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Human Physiology/Appendix 1: answers to review questions

This appendix does not provide answers to the review questions posted at the end of each chapter; it is a collection of questions provided at the end of each chapter.

Homeostasis
1. Meaning of Homeostasis:
 * A) contributor and provider
 * B) expanding
 * C) same or constant
 * D) receiver

2. What is the normal pH value for body fluid?
 * A) 7.15-7.2556
 * B) 7.35-7.45
 * C) 7.55- 7.65
 * D) 7.00-7.35
 * E) 6.5-7.5

3. An example of the urinary system working with the respiratory system to regulate blood pH would be
 * A) When you hold your breath the kidneys will remove CO2 from your blood
 * B) If you exercise a lot your urine will become more acidic
 * C) If you develop emphysema the kidneys will remove fewer bicarbonate ions from circulation
 * D) If you hyperventilate the kidneys will counteract the alkalinity by adding hydrogen ions into the blood stream
 * E) None of the above-the urinary system never works with the respiratory system

4. The urge to breathe comes in direct response to:
 * A) How long it has been since you last took a breath
 * B) The oxygen concentration of your surrounding environment
 * C) The buildup of nitrogen within your blood stream
 * D) The pH of your blood
 * E) The buildup of blood pressure that occurs when you don't breathe

5. In response to a bacterial infection my body's thermostat is raised. I start to shiver and produce more body heat. When my body temperature reaches 101 degrees, I stop shivering and my body temperature stops going up. This is an example of:
 * A) Negative feedback
 * B) A malfunctioning control system
 * C) Positive feedback
 * D) A negative impact

6. Which of the follow is an example of a positive feedback?
 * A) Shivering to warm up in a cold winter storm
 * B) A cruise control set on your car applies more gas when going up a hill
 * C) You sweat on a hot summer's day and the blood vessels in your skin vasodilate
 * D) You get cut and platelets form a clot. This in turn activates the fibrin clotting system and more blood forms clots

7. Where is the body's "thermostat" found?
 * A) Within the nervous system, in the Hypothalamus
 * B) Within the integumentary system, in the skin
 * C) Within the brain, in the corpus callosum
 * D) Within the Urinary system, in the kidneys

8. What system has little to contribute to the homeostasis of the organism?
 * A) Urinary System
 * B) Reproductive System
 * C) Respiratory System
 * D) Nervous System

Cell physiology
1. List 2 functions of the cell membrane:

 * Separates internal metabolic events from the external environment.
 * Controls the movement of materials into and out of the cell.

Questions 2 - 6 Match the following organelles with their function:

2. Mitochondria C

3. Vacuoles D

4. Cilia A

5. Smooth ER B

6. Golgi Apparatus E 7. The diffusion of H2O across a semi permeable or selectively permeable membrane is termed
 * A. Active transport
 * B. Diffusion
 * C. Osmosis
 * D. Endocytosis

8. Oxygen enters a cell via?
 * a. Diffusion
 * b. Filtration
 * c. Osmosis
 * d. Active transport

9. The term used to describe, "cell eating" is?
 * a. Exocytosis
 * b. Phagocytosis
 * c. Pinocytosis
 * d. Diffusion

10. Which of the following requires energy?
 * a. Diffusion
 * b. Osmosis
 * c. Active transport
 * d. Facilitated diffusion

11. Protein synthesis occurs at the
 * a. Mitochondria
 * b. Lysosomes
 * c. Within the nucleus
 * d. Ribosomes

12. Which of the following is not found in the cell membrane?
 * a. Cholesterol
 * b. Phospholipids
 * c. Proteins
 * d. Galactose
 * e. Nucleic Acids

13. What is a cell?
 * a. The largest living units within our bodies.
 * b. Enzymes that "eat" bacteria
 * c. Microscopic fundamental units of all living things.
 * d. All of the above.

Integumentary System
1. Name all of the parts of the integumentary system.
 * The integumentary system consists of the skin, the subcutaneous tissue below the skin, hair, nails, and assorted glands.

2. Name the cells that produce melanin and describe its function.
 * Melanocytes
 * These are cells located in the bottom layer of the skin's epidermis and in the middle layer of the eye, the uvea. Through a process called
 * melanogenesis, these cells produce melanin, a pigment in the skin, eyes, and hair.

3. Name and describe the importance of the cutaneous senses.
 * The cutaneous senses are touch, pressure, heat, cold and pain. Their purpose is to provide the central nervous system with information about the external environment and its effect on the skin.

4. Explain how sweating helps maintain normal body temperature.
 * Eccrine sweat glands are coiled tubular glands derived from the outer layer of skin but extending into the inner layer. The sweat glands are
 * controlled by sympathetic cholinergic nerves which are controlled by a centre in the hypothalamus. The hypothalamus senses core
 * temperature directly, and also has input from temperature receptors in the skin and modifies the sweat output, along with other thermoregulatory processes.

5. Explain where on the body hair has important functions, and describe these functions.
 * Hair on the scalp provides insulation from cold for the head.
 * The hair of eyelashes and eyebrows helps keep dust and perspiration out of the eyes.
 * Hair in our nostrils helps keep dust out of the nasal cavities.
 * Any other hair on our bodies no longer serves a function, but is an evolutionary remnant.

6. What is a melanoma?
 * a. The outermost layer of skin
 * b. A type of nail disease
 * c. A malignant tumor that originates in melanocytes
 * d. The lower most layer of skin

The Nervous System
1. The junction between one neuron and the next, or between a neuron and an effector is called:
 * A ) A synapse
 * B ) A dendrite
 * C ) A neuotransmitter
 * D ) A ventricle
 * E ) None of the above

2. A fast excitatory synapses follows this order:
 * A ) (1) neurotransmitter released  (2) diffused across the synaptic cleft to a receptor protein (3) binding of the transmitter opens pores in the ion channels and positive ions move in.
 * B ) (1) neurotransmitter released  (2) diffused across the synaptic cleft to a receptor protein (3) binding of the transmitter opens pores in the ion channels and negative ions move in.
 * C ) (1) neurotransmitter released  (2) diffused across the synaptic cleft to a receptor amino acid (3) binding of the transmitter opens pores in the ion channels and positive ions move in.
 * D ) (1) diffused across the synaptic cleft to a receptor protein (2) neurotransmitter released  (3) binding of the transmitter opens pores in the ion channels and positive ions move in.
 * E ) None of the above

3. Resting potential is
 * A ) excess positive ions accumulate inside the plasma membrane
 * B ) excess negative ions accumulate inside the plasma membrane
 * C ) excess positive ions accumulate outside the plasma membrane
 * D ) both b & c
 * E ) both a & c

4. Sensory neurons have:
 * A ) A short dendrite and a long axon
 * B ) A short dendrite and a short axon
 * C ) A long dendrite and a short axon
 * D ) A long dendrite and a long axon
 * E ) Their axons and dendrites may be either long or short

5. ________blocks Acetylcholine receptor sites causing muscle relaxation.
 * A ) Novocain
 * B ) curare
 * C ) Nicotine
 * D ) Nerve gases

6. Transmission across a synapse is dependent on the release of _______?
 * A ) neurotransmitters
 * B ) synaptic vesicle
 * C ) neurons
 * D ) receptor proteins

7. Motor neurons take messages
 * A ) from the muscle fiber to the central nervous system
 * B ) away from the central nervous system to the central nervous system
 * C ) that are classified
 * D ) away from the central nervous system to muscle fiber

8. The medulla oblongata helps to regulate which of the following:
 * A ) Breathing
 * B ) Heartbeat
 * C ) Sneezing
 * D ) Vomiting
 * E ) All of the above

9. The nervous systems main components are what?
 * A ) The Synapses and Sprinal cord
 * B ) The neurons and the synapses
 * C ) The brain and the neurons
 * D )The brain and the spinal cord

10. Explain what LTP does to enhance communication between two neurons, on the postsynaptic end.
 * More receptors, such as AMPA receptors, are added and existing ones are sensitized via phosphorylation. Dendritic spine number and surface area is increased as well.

11. Explain what LTP does to communication between two neurons, on the presynaptic end.
 * If the retrograde messenger theory is correct, presynaptic cells participate in the enhancement by increasing the probability of synaptic vesicle release. (Please remember the retrograde messenger is theoretical, I just thought it should be included here)

Critical Thinking: Vision
1. Explain why you are normally unaware of your blind spot.
 * Since your eyes are looking from different angles, they see each other's blind spot and your brain combines the two images.

2. Stare at a bright light for 10 seconds and then stare at a white sheet of paper. What do you observe and why?
 * You should observe a negative afterimage. This happens when the rod/cone (mostly cone) cells in your eye adapt to the stimulus and lose their sensitivity, leaving you with the negative of the color that was adapted to.

3. What is it that makes things "disappear" when you are staring at them at night, and how do you make them reappear?
 * There are no rods in the fovea, so little light is picked up when you stare directly at the object. To make it reappear, just don't look right at it.

4. Name what rods are sensitive to and also what cones are sensitive to.
 * Rods are more sensitive to lower light levels, but lack color-seeing ability. Cones work in brighter light and perceive color (blue, green, red).

5. Explain how Deadly Nightshade works
 * Normally, the parasympathetic nervous system constricts the pupil as needed with acetylcholine. The atropine in nightshade is a competitive agonist on the same receptor as the one that accepts acetylcholine. Basically: the atropine takes up all of the places for acetylcholine to bind, and the pupils dilate.

Critical Thinking: Hearing
1. Explain how the pitch of sound is coded. How is the loudness of sound coded?

2. What do the three semicircular canals in the inner ear enable us to do? How do they accomplish this?
 * Each of the three fluid filled canals is on a different plane. Movement is detected on these planes when the fluid inside moves around, vibrating cilia on the cupula which sends it on to the brain.

3. What does the eustachian tube do? What does the eustachian tube have to do with a middle ear infection?
 * The eustachian tube is to keep pressure in the middle ear the same as atmospheric pressure. If the tube is blocked, the gases in the ear will diffuse back into the surrounding tissues and a vacuum will be made. Eventually, this will pull fluid in and if it becomes infected... You have an ear infection.

4. What is the advantage of having a oval window?

Sound transducted from air to a more dense medium (endolymph, in scala media where the organ of cortis is placed) would be partially reflected and greatly weakened if not for the ossicular bones that transfer the vibration from membrana tymphani trough malleus, incus and stapes to the foramen ovale where it puts the liquids of cochlea in motion. This motion is then transfered trough membrana vestibularis to membrana basilaris, which in turn puts the haircells in motion. This leads to a bending of the stereocills, fastened to membrana tectori, and as a result; a depolarization of the afferent sensory fibre receptor of n. cochlearis through release of glutamate. The loss of energy in transduction is partially re-gained by the size of membr. tympani compared to the size of foramen ovale and the rotation of the ossicular bones.

Review Questions
1. Located under the hardest bone in the body, these control not only hearing but also a sense of gravity and motion:
 * A) The incus and the stapes
 * B) The pinna and the ear drum
 * C) the vestibular nerve and the semi circular canals
 * D) The eustachian tube and the stapes

2.  The retina does the following;
 * A) allows vision in light and dark, using cones and rods
 * B) Gives depth perception using binocular vision
 * C) Contains the ciliary muscles that control the shape of the lens
 * D) Protects and supports the shape of the eye

3. This is the reason that we stop feeling the clothes that we are wearing
 * A) Merkel’s Discs are somewhat rigid in structure, and the fact that they are not encapsulated, causes them to have a sustained response
 * B) Meissner’s corpuscle are rapidly adapting or phasic, the action potentials generated quickly decrease and eventually cease
 * C) Ruffini corpuscles is a class of slowly adapting mechanoreceptor
 * D) Pacinian corpuscles allow sodium ions to influx in, creating a receptor potential

4. When eating a piece of candy, I will use the following to sense that it is sweet
 * A) Fungiform papillae
 * B) Filiform papillae
 * C) Foliate papillae
 * D) Circumvallate papillae
 * E) All of the above

5. If I have a cold, food may not taste as good to me because
 * A) The nerve fibrils are not functioning properly
 * B) My food will taste the same; taste and smell have nothing in common
 * C) Papilla become blocked by mucus and are unable to function
 * D) Olfaction, taste and trigeminal receptors together contribute to the flavor of my food

6. Walking from a well lit room into a dark room would cause the following to occur
 * A) The sclera in the eye to open and eventually allow me to see in the dark
 * B) The extraocular muscles in the eye to open and eventually allow me to see in the dark
 * C) The cones in the eye to open and eventually allow me to see in the dark
 * D) the rods in the eye to open and eventually allow me to see in the dark

7. Hair cells in the ear
 * A) Are the actual sensory receptors that will fire off action potentials when they are disturbed
 * B) Show a graded response, instead of the spikes typical of other neurons
 * C) “Rub” against the overhanging tectorial membrane
 * D) All of the above

8. Eyesight decreases with age because
 * A) Older eyes receive much less light at the retina
 * B) There are numerous eye diseases that can affect an older eye
 * C) The extent to which the pupil dilates decreases with age
 * D) all of the above

9. Teens walking off of a roller coaster in Magic Mountain seem to have vertigo because
 * A) The fluid in the auricle has not stopped moving causing conflicts with the information coming from your vision
 * B) the fluid in the cochlea has not stopped moving causing conflicts with the information coming from your vision
 * C) The fluid in the tympanic membrane has not stopped moving causing conflicts with the information coming from your vision
 * D) The fluid in the stirrup has not stopped moving causing conflicts with the information coming from your vision

10. These receptors react to foods treated with monosodium glutamate
 * A) Salt
 * B) Sour
 * C) Bitter
 * D) Sweet
 * E) Umami

The Muscular System
1. Smooth Muscle is
 * A) Voluntary and Spindle Shaped
 * B) Voluntary and Striated
 * C) Involuntary and Spindle Shaped
 * D) Involuntary and Striated

2. Skeletal Muscle is
 * A) Voluntary and Spindle Shaped
 * B)Voluntary and Striated
 * C) Involuntary and Spindle Shaped
 * D) Involuntary and Striated

3. Cardiac Muscle is
 * A) Voluntary and Spindle Shaped
 * B) Voluntary and Striated
 * C) Involuntary and Spindle Shaped
 * D) Involuntary and Striated

4. Which type of muscle cell is multinucleated?
 * A) Cardiac
 * B) Smooth
 * C) Skeletal
 * D) All of the Above

5. What is an example of a smooth muscle?
 * A) Masseter (Face)
 * B) Bladder
 * C) Heart
 * D) Pronator Teres (Forearm)
 * E) Rectus Abdominis (belly)

6. Each myosin filament is surrounded by ____ actin filaments.
 * A) Two
 * B) Four
 * C) Six
 * D) Eight
 * E) Seven

7. The muscular system is controled by what system?
 * A) The cardiovascular system
 * B) The integumentary System
 * C) The Nervous system
 * D) None of the above

8. How many types of muscle are there?
 * A) Two
 * B) Three (cardiac, smooth and skeletal)
 * C) Four
 * D) Five

Blood Physiology
1. Taking aspirin every day can reduce the risk of heart disease because:
 * A) it is a powerful vasodilator
 * B) it blocks pain receptors in heart tissue
 * C) it stops ventricular fibrillation
 * D) it loosens plaque on arterial walls

2. A hematocrit measures percentage of:
 * A) White blood cells
 * B) Plasma
 * C) Platelets

3. Fred's blood type is O- and Ginger's is B+. Fred and Ginger have a son who is AB+. What do you conclude?
 * A) If they have a second child Ginger needs to have RhoGam shot
 * B) There is no risk to a second child, unless it has a negative blood type
 * C) If the child needs a blood transfusion Fred could provide it safely, but not Ginger

4. Which blood component plays the largest role in maintaining the osmotic pressure of blood?

 * B) carbon dioxide
 * C) white blood cells
 * D) fibrinogen
 * E) globulins

5. If you hold your breath for one minute
 * A) The kidneys will increase sodium ion reabsorption

 * C) Your heart rate will greatly slow
 * D) Hemoglobin will bind to oxygen more strongly

6. Most of the carbon dioxide produced by tissues is transported to the lungs as:
 * A) Small gas bubbles in the plasma
 * B) Gas bound to hemoglobin in the red blood cells

 * D) Gas bound to white blood cells and albumin
 * E) Gas transported through the lymphatic system

7. To prevent blood loss after a tissue injury, blood vessels first
 * A) Form a platelet plug
 * B) Form a clot
 * C) Initiate the coagulation cascade

8. You take a blood sample from a male cyclist at the end of a long race. The hematocrit is 60%. The most likely conclusion is:
 * A) This is within normal range for most adult males
 * B) This cyclist is anemic
 * C) This low of a hematocrit could indicate liver damage or leukemia

 * E) The cyclist has been taking pharmaceutical erythropoietin

9. In a normal blood sample, which of the following cells will be the most abundant?

 * B) Basophils
 * C) Eosinophils
 * D) Monocytes
 * E) Lymphocytes

10. A bag of donated blood does not clot because
 * A) There is not enough oxygen
 * B) It cannot dry out
 * C) It is kept refrigerated
 * D) There is no free calcium
 * E) All of the above

The cardiovascular system
1. This conducts electricity like nerves
 * A) Epicardium
 * B) Pericardium
 * C) Myocardium
 * D) Subvalaular Apparatus
 * E) None of these, only nerves conduct electricity

2. This carries the most blood at any given time in the body
 * A) Veins
 * B) Capillary Beds
 * C) Veins
 * D) Aorta
 * E) Vena Cava

3. The following contract together to pump blood
 * A) Right atrium with the right ventricle and left atrium with the left ventricle
 * B) Right atrium with left atrium and right ventricles with left ventricle
 * C) Tricuspid valve and mitral valve
 * D) Aorta and pulmonary artery
 * E) Aorta, pulmonary artery and pulmonary vein

4. This is the pacemaker of the heart
 * A) AV node
 * B) Purkinje fibers
 * C) AV Bundle
 * D) SA node
 * E) None of these, a pacemaker is surgically inserted

5. When reading an EKG, this letter shows the depolarization from the AV node down to the AV bundle
 * A) S
 * B) P
 * C) U
 * D) T
 * E) Q

6. The T wave in an EKG shows
 * A) Resting potential
 * B) Atrial depolarization
 * C) SA node excitation
 * D) Ventricle repolarization
 * E) Purkinje Excitation

7. Blood pressure is the measure of
 * A) Pressure exerted by the blood on the walls of the blood vessels
 * B) Pressure exerted by the blood on the arteries
 * C) Pressure exerted by the blood on the veins
 * D) Pressure exerted by the blood on the aorta

8. Systolic Pressure is
 * A) An average of 120 mm Hg
 * B) Lowers steadily during ventricle systole
 * C) The highest when blood is being pumped out of the left ventricle into the aorta
 * D) An average of 80 mm Hg
 * E) Both A and C
 * F) Both B and D

9. The heart has how many chambers?
 * A) One
 * B) Two
 * C) Three
 * D) Four (two ventricles and two atria)
 * E) Five

10. End diastolic volume in human
 * A)120mL
 * b)50mL
 * c)70mL
 * d)100mL

The Immune System
1-When neutrophils and macrophages squeeze out of capillaries to fight off infection it is called:
 * A) phagocytosis
 * B) hemolysis
 * C) interleukin
 * D) diapedesis
 * E) folliculitis

2-During a great battle between your WBC's and an aggressive microbe, an inflammatory response has been initiated. Reddness and edema has kicked in what else does the body do to protect itself?
 * A) Histamine cause vasodilation
 * B) Hypothalmus raises the thermostat
 * C) Neutrophils engulf and destroy the microbe
 * D) Living and dead WBC and bacteria accumulate
 * E) All of the above

3-Specificity and memory are associated with which body defense mechanism?
 * A) inflammatory response
 * B) phagocytosis by macrophages and neutrophils
 * C) interferon
 * D) T cell and B cell responses
 * E) anatomical barriers in the body

4-An additional chemical defense found in tears and saliva?
 * A) T lymphocytes
 * B) saline
 * C) lysozyme
 * D) EFC

5-Which of the following does complement protein perform
 * A) They cause antibody release
 * B) T cell development
 * C) The release if histamine
 * D) Promotes tissue repair
 * E) Mast cell degranulation

6-Which substance induces fever?
 * A) Pyrogen
 * B) Pus
 * C) Monocytes
 * D) Edema
 * E) Interferon

7-Major function(s) of the lymphatic system is/are?
 * A) provide route for return of extracellular fluid
 * B) act as drain off for inflammatory response
 * C) render surveillance, recognition, and protection against foreign materials via lymphocytes, phagocytes, and antibodies.
 * D) a and c
 * E) all of the above

8-An antigen is:
 * A) a chemical messenger that is released by virus infected cells
 * B) a lymphocyte responsible for cell-mediated immunity
 * C) something that coats the inside of lungs, causing infection
 * D) a protein or other molecule that is recognized as non-self
 * E) a thick yellow-white fluid

9-A foreign substance, usually a protein, that stimulates the immune system to react, such as by producing antibodies is a ______________.
 * A) allergen
 * B) antigen
 * C) histamine
 * D) mast cell
 * E) interferon

10-When a macrophage ingests an invading bacteria and takes the antigen to a lymph node, what happens next?
 * A) the macrophage will present it to the first B-cell it encounters, and the B-cell will in turn change its surface receptors to match the antigen
 * B) a B-cell will only become activated if it already has a match for the antigen
 * C) a matching B-cell will become activated into a cytotoxic T-cell
 * D) the cells of the lymph node will release histamine
 * E) the lymph node will increase production of neutrophils

11-What is the most common portal of entry for diseases, into the body?
 * A) Respiratory system
 * B) Endocrine system
 * C) Hematacrit system
 * D) Any opening into the body.

12-This gland shrinks in size during adulthood, and has hormones that function in maturation of T-lymphocytes:
 * A) lymph nodes
 * B) thymus
 * C) spleen
 * D) GALT
 * E) tonsils

13-Which of the following is not a mechanical factor to protect the skin and mucous membranes from infection?
 * A) Layers of cells
 * B) Tears
 * C) Saliva
 * D) Lysozyme
 * E) None of the above

14-Where is the site of maturation for a B cell?
 * A) thymus
 * B) bone marrow
 * C) pancreas
 * D) cortex

15-Nonspecific resistance is
 * A) The body's ability to ward off diseases.
 * B) The body's defenses against any kind of pathogen.
 * C) The body's defense against a particular pathogen.
 * D) The lack of resistance.
 * E) None of the above.

16-What is an Antibody?
 * A) An antimicrobial substance applied to a living tissue to prevent infection.
 * B) Programmed cell death
 * C) A protein generated by the immune system in response to a foreign substance.
 * D) A chemical involved in inflammation.

The Urinary System
1. While reading a blood test I notice a high level of creatinine, I could assume from this that
 * A) There is a possibility of a UTI
 * B) There is a possibility of diabetes
 * C) There is a possibility of kidney failure
 * D) There is nothing wrong, this is normal

2. Direct control of water excretion in the kidneys is controlled by
 * A) Anti-diuretic hormone
 * B) The medulla oblongata
 * C) Blood plasma
 * D) Sodium amounts in the blood
 * E) Cells

3. Nephrons
 * A) Eliminate wastes from the body
 * B) Regulate blood volume and pressure
 * C) Control levels of electrolytes and metabolites
 * D) Regulate blood pH
 * E) All of the above

4. If I am dehydrated, my body will increase
 * A) ATP
 * B) CDP
 * C) Diluted urine
 * D) ADH

5. Which part of the nephron removes water, ions and nutrients from the blood?
 * A ) vasa recta
 * B ) loop of henle
 * C ) proximal convoluted tubule
 * D ) peritubular capillaries
 * E ) glomerulus

6.Kidneys have a direct effect on which of the following
 * A ) Blood pressure
 * B ) How much water a person excretes
 * C ) Total blood volume
 * D ) pH
 * E ) all of the above

7. Why do substances in the glomerulus enter the Bowman's capsule?
 * A ) the magnetic charge of the Bowman's capsule attracts the substances
 * B ) the substances are actively transported into the Bowman's capsule
 * C ) blood pressure of the glomerulus is so great that most substances in blood move into capsule
 * D ) little green men force it in with their ray guns

8. What happens in tubular excretion?
 * A ) urine bonds are formed between the wastes
 * B ) wastes are diffused from the tubule
 * C ) wastes move into the distal convoluted tubule from the blood
 * D ) blood pressure forces wastes away from the kidney

9. The countercurrent exchange system includes_________and_________.
 * A ) glomerulus and macula densa
 * B ) proximal convoluted tubule and distal convoluted tubule
 * C ) loop of  Henle and collecting tubule
 * D ) afferent arteriole and efferent arteriole
 * E ) ureters and bladder

10. The function of the loop of the nephron in the process of urine formation is:
 * A ) reabsorption of water
 * B ) production of filtrate
 * C ) reabsorption of solutes
 * D ) secretion of solutes

The respiratory system
1. This is total lung capacity :*A) Vital capacity :B) Tidal volume :C) Expiratory reserve volume :D) Inspiratory reserve volume 2. Involuntary breathing is caused by the
 * A) Pituitary gland :B) Exocrine gland :C) Cerebral cortex :*D) Medulla oblongata :E) Endocrine gland 3. Carbon monoxide is dangerous because :*A) It binds strongly to hemoglobin, making it unavailable to oxygen :B) It binds strongly to plasma, making it unavailable to carbon dioxide :C) It raises the blood’s pH level, causing a person to hyperventilate :D) Carbon monoxide is not harmfull, we have it in our bodies normally 4. Clubbing of the fingers could be a sign of :A) A viral infection :B) An upper respiratory infection :*C) Chronic Obstructive Pulmonary Disease :D) Nothing, it’s inherited 5. The need to breathe is caused by :*A) A decrease in blood pH :B) An increase in blood pH :C) A decrease in blood oxygen levels :D) A decrease in carbon dioxide levels 6. A person more susceptible to Chronic Obstructive Pulmonary Disease would be :A) A long time smoker :B) A long time fireman :C) A child whose parents smoke :D) A farmer that deals with pesticides :*E) All of the above

7. The exchange of gases between the blood within the capillaries and tissue fluid surrounding the body's cells is called? :A) external respiration :B) cell metabolism :C) cellular respiration :*D) internal respiration 8. The medulla oblongata and pons regulate and measure what?
 * A) The pH level of your blood
 * B) Your body temperature
 * C) The amount of O2 in your blood
 * D) The amount of air in your lungs

9. About how many alveoli are there in the lungs?
 * A) 300 million
 * B) 300 billion
 * C) 300 trillion
 * D) 300 thousand
 * E) None of the above 10. In relation to atmospheric pressure, intrapleural pressure is: :A) more pressurized :*B) less pressurized :C) about the same

11. Hemoglobin gives up oxygen when the environment is more _______. :*A)Acidic :B)Alkaline :C)Icey :D)Open 12. The sac that surrounds your lungs is called what? :A) Diaphragm :*B) Visceral Pleura :C) Pulmonary Thorax :D) None of the above 13. In what cellular organelle is the oxygen actually consumed and carbon dioxide produced?
 * A) Nucleus
 * B) Cytoplasm
 * C) Microfilaments
 * D) Mitochondria

14. Which of these are protective reflexes?
 * A) Hiccuping
 * B) Sobbing
 * C) Sneezing
 * D) Itching

15. Where does gas exchange take place?
 * A) Bronchioles
 * B) Conchae
 * C) Pulmonary Capillaries
 * D) Roots of the Lungs

16. When you hyperventilate you release large amounts of CO2 and drop your O2 levels. As a result you loose the urge to breathe and may pass out. This is called what? :A) Chronic Obstructive Pulmonary Disease :B) Asthma :*C) Shallow water black out :D) Pulmonary Fibrosis 17. Acidosis is when you blood pH is below ? :A) 7.05 :B) 7.15 :C) 7.25 :*D) 7.35 18. When we exhale deeply some air is still left in the lungs, this air left is called? :A) Tidal Volume :B) Vital Capacity :C) Expiratory reserve Volume :*D) Residual Volume

The gastrointestinal system
1. This is released in the duodenum in response to acidic chyme
 * A) Cholecystokinin
 * B) Gastrin
 * C) Secretin
 * D) Peptide

2. In the GI tract, this layer is responsible for absorption and secretions
 * A) Mucosa
 * B) Sub mucosa
 * C) Muscularis
 * D) Serosa

3. This digestive enzyme is produced in the salivary glands and the pancreas
 * A) Maltase
 * B) Amylase
 * C) Pepsin
 * D) Nuclease
 * E) Lipase

4. This keeps the chyme in the stomach until it reaches the right consistency to pass into the small intestine
 * A) Esophageal sphincter
 * B) Intrinsic sphincter
 * C) Cardiac sphincter
 * D) pyloric sphincter

5. The site where most of the chemical and mechanical digestion is carried out
 * A) Pylorus
 * B) Fundus
 * C) Stomach
 * D) Large intestine
 * E) Small intestine

6. Parietal cells secret
 * A) Serotonin
 * B) Mucus
 * C) Pepsinogen
 * D) Hydrochloric Acid
 * E) Gastrin

7. The cells at the base of fundic or oxyntic glands
 * A) Chief cells
 * B) G cells
 * C) Argentaffin cells
 * D) Goblet cells
 * E) Parietal cells

8. The movement and the flow of chemicals into the stomach is controlled by
 * A) Nervous system
 * B) Pancreas
 * C) Various digestive system hormones
 * D) Liver
 * E) Both the nervous system and various digestive system hormones

9. The function of the Ileum is
 * A) Absorb nutrients
 * B) Absorb vitamin B12 and bile salts
 * C) To introduce bile and pancreatic juices
 * D) Absorb alcohol and aspirin

10. The liver does this
 * A) Glycogen storage
 * B) Plasma protein synthesis
 * C) Bile production
 * D) Drug detoxification
 * E) All of the above

11. How many layers is the G.I tract composed of?
 * A)Two
 * B)Three
 * C)Four (mucosa, submucosa, muscularis, serosa)
 * D)Five

12. Name the 7 accessory organs.
 * Salivary glands, parotid gland, submandibular gland, sublingual gland, tongue, teeth, liver, gallbladder, pancreas, vermiform appendix

Nutrition
1. Nonessential amino acids
 * A) are stored in the body
 * B) are only needed occasionally
 * C) can be produced in the body
 * D) can be taken in supplements

2. Micronutrients include
 * A) minerals and vitamins
 * B) lipids and fatty acids
 * C) amino acids and proteins
 * D) vitamins and minerals

3. The body requires amino acids to
 * A) produce new red blood cells
 * B) produce new protein
 * C) replace damaged red blood cells
 * D) replace damaged protein
 * E) A and C
 * F) B and D

4. The function of lipids
 * A) store energy
 * B) organ protection
 * C) temperature regulator
 * D) emulsifiers
 * E) all of the above

5. This vitamin is a vital component of the reproductive process and lowers the risk of getting cancer
 * A) B12
 * B) Folic Acid
 * C) Niacin
 * D) Thiamine
 * E) Retinol

6. This vitamin is needed to make red blood cells
 * A) B1
 * B) B2
 * C) B6
 * D) B12

7. This participates in the synthesis of hemoglobin and melanin
 * A) Copper
 * B) Chloride
 * C) Calcium
 * D) Iron
 * E) Iodine

8. I go to visit my grandmother and see that she has multiple bruises- from this I may assume that
 * A) she has a vitamin A deficiency
 * B) she is old and just clumsy
 * C) she has a vitamin K deficiency
 * D) she has scurvy
 * E) she has rickets

9. As a pirate I may get scurvy because
 * A) I am not getting enough vegetables on the ship
 * B) I am not getting enough fruit on the ship
 * C) I am eating too much fish on the ship
 * D) I am getting too much sun on the ship
 * E) I am drinking too much rum on the ship

10. I am taking anticoagulant medication and it doesn’t seem to be working, this could be because
 * A) I have too much vitamin A
 * B) I have too much B12
 * C) I have too much sodium
 * D) I have too much vitamin E
 * E) I have too much vitamin K

11. Which of these are fat soluable?
 * A) Vitamin K
 * B) Vitamin E
 * C) Vitamin D
 * D) Vitamin A
 * e) All of the above

The Endocrine System
1. My child just fell and was hurt, the anxious feeling that I feel is caused by
 * A) glucagon
 * B) insulin
 * C) epinephrine                       ANS=C
 * D) adrenocorticotropic
 * E) None of these

2. All of Bob’s life he has had to take insulin shots, this is caused because
 * A) his beta cells don’t function correctly                                ANS= A
 * B) his alpha cells don’t function correctly
 * C) his DA hormone isn’t functioning correctly
 * D) his GHRH hormone isn’t functioning correctly

3. The reason iodine is in salt is
 * A) to prevent diabetes
 * B) to prevent simple goiters
 * C) to prevent addison’s disease
 * D) to prevent cushing syndrome

4. All hormones react to a negative feedback except
 * A) progesterone
 * B) estrogen
 * C) prolactin
 * D) oxytocin
 * E) none of these                           ANS =E

5. If I have a high blood calcium level it may be due to
 * A) calcitonin
 * B) parathyroid
 * C) glucocorticoids
 * D) glucagon

6. Hormones that are lipids that are synthesized from cholesterol
 * A) protien
 * B) amino acid-derived
 * C) polypeptide
 * D) steroids                              ANS =D
 * E) eicosanoids

7. This type of hormone must bind to a receptor protein on the plasma membrane of the cell
 * A) water soluble
 * B) lipid soluble              ANS=E
 * C) steroid
 * D) polypeptide
 * E) a and d
 * F) b and c

8. Endocrine glands release hormones in response to
 * A) Hormones from other endocrine glands            ANS =C
 * B) Chemical characteristics of the blood
 * C) Neural stimulation
 * D) All of the above

9. The anterior pituitary secretes
 * A) oxytocin
 * B) endorphins
 * C) ADH                ANS C
 * D) TRH

10. Chief cells produce
 * A) epinephrine
 * B) glucagon
 * C) insulin             ANS A
 * D) mineralocoticoids
 * E) parathyroid hormone

11. Name the eight major endocrine glands.
 * Pituitary gland, thyroid gland, parathyroid gland, pancreas, testes/ovaries, adrenal gland, pineal gland
 * Pituitary gland, thyroid gland, parathyroid gland, pancreas, testes/ovaries, adrenal gland, pineal gland

12. Name the four major groups hormones can be chemically classified into.
 * Amino acid-derived, polypeptides/proteins, steroids, eicosanoids, glycoprotein, amines
 * Amino acid-derived, polypeptides/proteins, steroids, eicosanoids, glycoprotein, amines

The male reproductive system
1. This is needed to make immature sperm mature
 * A) FHS
 * B) LH
 * C) FSH
 * D) HL

2. These become engorged with blood in an erection
 * A) corpora cavernosa
 * B) fibrous envelope
 * C) septum pectiniforme
 * D) integument
 * E) dorsal veins

3. The difference between male and female sperm
 * A) female sperm have a larger head
 * B) male sperm are lighter
 * C) female sperm are faster
 * D) male sperm are weaker
 * E) A and B
 * F) C and D

4. The entire process of sperm formation takes about
 * A) 5-6 weeks
 * B) 7-8 weeks
 * C) 3-4 weeks
 * D) 9-10 weeks

5. Hyper Activation occurs when
 * A) the sperm are introduced into the urethra
 * B) the sperm are ejaculated into the vaginal canal
 * C) the sperm begin to interact with the fertilizing layer of an egg cell
 * D) the sperm reach the cervix

6. It takes sperm ___________ weeks to travel through the epididymis
 * A) 6-8
 * B) 1-3
 * C) 2-4
 * D) 4-6

7. While singing in the choir, Ben suddenly notices his voice is constantly cracking. This is caused by
 * A) androgens
 * B) LH
 * C) FSH
 * D) Ben’s inability to sing

8. In sexual homology, the glans penis in the male is equal to _____________ in the female
 * A) clitoral hood
 * B) clitoris
 * C) clitoral glans
 * D) clitoral crura

9. In sexual homology, the ___________ in the male is equal to the fallopian tubes in the female
 * A) testis
 * B) appendix testis
 * C) vas deferens
 * D) seminal vesicle
 * E) efferent ducts

10. Joe has a bulge in the groin area that seems to get worse when he lifts things. This most likely is
 * A) epididymitis
 * B) testicular cancer
 * C) varicocele
 * D) hydrocele
 * E) inguinal hernia

The female reproductive system
1. In homology, the __________ in the female is equal to the penis in the male
 * A) labia majora
 * B) clitoral hood
 * C) clitoris
 * D) labia minora
 * E) none of the above

2. This contains some of the strongest muscles in the human body
 * A) uterus
 * B) clitoris
 * C) cervix
 * D) labia majora

3. This protects the vaginal and urethral openings
 * A) labia majora
 * B) labia minora
 * C) clitoris
 * D) urethra

4. Sally has noticed that her cervical mucus has changed and now resembles egg whites- from this Sally could assume
 * A) her period will begin soon
 * B) nothing, this is a normal occurrence
 * C) she has a yeast infection
 * D) she is ovulating

5. Debbie recently went to the OBGYN and was diagnosed with PCOD (polycystic ovary syndrome) because of this she has
 * A) nothing, its normal in women
 * B) antisperm antibodies
 * C) an overproduction of LH
 * D) leaking of milk from her mammary glands
 * E) problems becoming pregnant

6. Angie went to the doctor because she has had pain in her leg recently- this could be caused by
 * A) ovulation pain
 * B) her period that will be starting tomorrow
 * C) premenstrual syndrome
 * D) a blood clot resulting from her birth control pill

7. Sue recently started her period and has noticed that they are very heavy and painful, and that they are inconsistent in their timing. One explanation could be
 * A) endometriosis
 * B) ovarian cancer
 * C) candidiasis
 * D) toxic shock syndrome
 * E) amenorrhea

8. Mary is getting married and is not ready to become a mother- she chooses this birth control because of its high effectiveness
 * A) natural family planning
 * B) a diaphragm
 * C) contraceptive injections
 * D) a spermicide foam

9. The release of LH in woman causes
 * A) menstration
 * B) ovulation
 * C) increase of endometrial lining
 * D) decrease of endometrial lining
 * E) nothing LH only does something in the male reproductive system

10. When the ovaries stop producing estrogen, this occurs
 * A) ovulation
 * B) implantation
 * C) premenstrual syndrome
 * D) menopause

11. Infertility affects what percentage of couples?
 * A) 5%
 * B) 10%
 * C) 15%
 * D) 20%

12. What is the only 100% effective form of birth control?
 * A) Tubal ligation
 * B) IUD
 * C) Natural family planning
 * D) Abstinence

Pregnancy and birth
1. Is at this stage that an egg implants in the uterine lining
 * A) morula
 * B) zygote
 * C) blastocyst
 * D) embryoblast

2. Which part of the embryoblast will become the central nervous system in development
 * A) ectoderm
 * B) mesoderm
 * C) endoderm

3. This hormone is only produced in the human body when a woman is pregnant
 * A) estrogen
 * B) HCG
 * C) progesterone
 * D) FSH
 * E) LH

4. By this week of pregnancy, the beginnings of all major organs have formed
 * A) 4
 * B) 7
 * C) 5
 * D) 6
 * E) 8

5. Stem cells are found in the embryoblast and use of them is very controversial, another place to find stem cells that are usable to treat leukemia and other disorders is the
 * A) morula
 * B) chorion
 * C) amnion
 * D) amniotic fluid
 * E) umbilical cord

6. The cervix dilates on an average of ______ per hour in the active phase of labor
 * A) 2 mm
 * B) 2 cm
 * C) 1mm
 * D) 1 cm

7. The contractions of the uterus are stimulated by the release of
 * A) oytocin
 * B) FSH
 * C) LH
 * D) prolactin
 * E) estrogen

8. A sign of pre-labor is
 * A) irregular contractions
 * B) pain in the front only
 * C) loss of the mucus plug
 * D) contractions stop during rest

9. This is the most common complication of pregnancy
 * A) preclampcia
 * B) miscarriage
 * C) smoking
 * D) Rh factor
 * E) teratogens

10. Sue decides to breastfeed because she has been told that colostrum contains
 * A) high protein
 * B) low fat
 * C) immunoglobulins
 * D) all of the above
 * E) none of the above

11. What is the first milk, after birth, called?
 * A) thrush
 * B) mastitis
 * C) colostrum
 * D) milk let down

Genetics and inheritance
1. DNA is found on
 * A) mitochondria
 * B) ribosomes
 * C) chromosomes
 * D) cytoplasm

2. Even though each cell has identical copies of all of the same genes, different cells __________ or ___________ different genes
 * A) express, repress
 * B) genotype, phenotype
 * C) dominate, recessive

3. In diploid organisms, a dominant allele on one chromosome will
 * A) show the expression of a recessive allele
 * B) mask the expression of a recessive allele
 * C) show that there are dominant alleles on both chromosomes
 * D) none of the above

4. Transcription occurs in the
 * A) cytoplasm
 * B) gogli apparatus
 * C) mitochondria
 * D) nucleus

5. This is the start codon and is found at the beginning of each mRNA
 * A) AGU
 * B) GAU
 * C) UAG
 * D) GUA
 * E) AUG

6. Sara was born with cystic fibrosis, from this we could assume that
 * A) all of her siblings also have cystic fibrosis
 * B) only her dad is a carrier
 * C) only her mom is a carrier
 * D) both of her parents are carriers

7. Jesse was born with a flattened face, almond eyes and less muscle tone; it could be assumed that he has
 * A) a chromosome abnormality on chromosome 21
 * B) a chromosome abnormality on chromosome 19
 * C) a chromosome abnormality on chromosome 20
 * D) a chromosome abnormality on chromosome 22
 * E) No chromosome abnormality, these are his inherited traits

8. The most common inherited disease is
 * A) hemochromatosis
 * B) cystic fibrosis
 * C) sickle cell anemia
 * D) hemophilia
 * E) all of the above

9. Being a carrier of sickle cell anemia means that the person will
 * A) also be a carrier of hemophilia
 * B) be resistant to malaria
 * C) have children that all have sickle cell anemia
 * D) have children that all have malaria
 * E) none of the above

10. Hemophilia is
 * A) a Y linked disease
 * B) an XY linked disease
 * C) an X linked disease

Development: birth through death
1. Growth is the most rapid in
 * A) puberty
 * B) childhood
 * C) infancy
 * D) adulthood
 * E) Growth is always the same

2. This hormone stimulates puberty
 * A) GnRH
 * B) LH
 * C) FSH
 * D) TSH

3. Compared to girls' early growth spurt, growth __________in boys and __________
 * A) is quicker, lasts longer
 * B) accelerates more slowly, lasts longer
 * C) is slower, shorter
 * D) None of the above

4. This quality symbolizes adulthood in most cultures
 * A) stability
 * B) method/tact
 * C) endurance
 * D) objectivity
 * E) all of the above

5. Susie has a very hard time keeping friends, according to Maslow, this could be because
 * A) as a child she had a supportive family
 * B) she likes to help solve the problems of others
 * C) as a teenager her self-esteem was low
 * D) as a baby she wasn’t breastfed
 * E) as a child she lived in an environment that never made her feel safe

6. According to Maslow, in order for me to reach my full potential of self-actualization I must first
 * A) feel safe
 * B) gain self-esteem
 * C) have friendship
 * D) have food
 * E) all of the above

7. Humans are one of the _________ developing species in the animal kingdom
 * A) slowest
 * B) quickest
 * C) average
 * D) none of the above

8. Jenny thinks that she might be going through menopause, a symptom of this is
 * A) bleeding
 * B) frequent urination
 * C) itchiness
 * D) none of the above
 * E) all of the above

9. It is estimated that 52 million people will be afflicted with this by 2010
 * A) Progeria
 * B) osteoporosis
 * C) Alzheimer’s
 * D) dementia

10. This is the leading cause of death for both men and women
 * A) progeria
 * B) cancer
 * C) congestive heart failure
 * D) osteoporosis
 * E) heart attack


text:
Human Physiology/Page List

This is an automatic page listing of all pages associated with this book.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Human Physiology/Page List


text:
User:JDowney

spladinkle@gmail.com

title: User:JDowney


text:
User:D.E. Wittkower

No real info here. Try my other userpage.

title: User:D.E. Wittkower


text:
User:SBJohnny/howto guidelines worksheet

Introduction

 * General definition of how-tos
 * How-to books are textbooks designed for use in a vocational setting. This setting might be a classroom, a family project, or for self-teaching. Topic areas include home economics, crafts, construction and repair, and so on.

 * Goals
 * Completed how-to books should provide clear and easy to understand instructions for the project at hand. These instructions should be accessible to a beginner, but detailed enough to be of use to an expert.

Standards
('Note - a good example is Cookbook
 * Accurate descriptions of processes, easy to follow step-by step instructions
 * Tools and materials well-described (linking to wikipedia may be acceptable in some instances)
 * Well-categorised
 * (In general, the how-to categories need to be cleaned up to allow for clear structure).
 * Suggested splits below
 * Well-defined topics
 * Particular modules should not describe more than one process. If there are alternative processes, perhaps use something like the disambig pages on wikipedia.
 * Not too narrow: unless a project has multiple stages that justify independent treatment (e.g.: "building a house"), it's better to keep the process on one page.
 * Flowcharts may be useful: some how-to modules may require flow charts for steps. This may override the preference for keeping all the steps on one page.

Transwikis

 * Transwikis should be cleaned up and then put into the proper (sub) categories. In the case of transwikied articles from wikipedia that contain how-to information only in part, it may be useful to create a page using the form MODULENAME/Transwiki, and use it as source material for the main module. The contribution history from the wikipedia side can be placed onto the talk page of the "/Transwiki" page.

Category structure

 * Vocational manuals
 * Cooking
 * Recipes
 * Ingredients
 * Equipment
 * Outdoor cooking
 * Barbecue
 * Campfire cooking
 * Gardening
 * Survival
 * Disasters
 * Camping
 * Shelters
 * Foraging
 * Campfire cooking
 * Construction
 * Crafts
 * Woodworking
 * Metalworking
 * Stoneworking
 * Cloth and fibre
 * Maintenence
 * Automotive maintenence
 * Home
 * Machine
 * Electronics
 * Self-help
 * Learning
 * Presentation


text:
Category:Book:Philately

ru:Категория:Филателия

title: Category:Book:Philately


text: Category:Book:Urban Calligraphy

title: Category:Book:Urban Calligraphy


text:
Talk:A-level Mathematics/Advanced/Basic Mechanics/Space and Time

I strongly think that relativity does not belong here. It should have a separate section for those that are interested in reading about it. However, from studying Edexcel modules M1 and M2, I am quite sure that A-level mechanics deals solely with Newtonian physics and laws! --FSHero 17:17, 7 August 2006 (UTC)

I wouldn't mind a few more paragraph breaks in the page. Otherwise quite informative. --195.137.75.44 (talk) 18:55, 27 March 2008 (UTC)


text: Category:Book:XHTML

title: Category:Book:XHTML


text:
Speech-Language Pathology/Stuttering/Defstut

 Anti-stuttering technology: DAF, MAF. Pocket-size. Monaural (one ear) or binaural (two ears). Website: http://www.defstut.com Price: US$295

Personal Experiences Using Defstut
Please read Speech-Language Pathology/Stuttering/How to Participate in this Wikibook before adding material.


text: Category:Book:YafaRay

title: Category:Book:YafaRay


text:
Speech-Language Pathology/Stuttering/VoiceAmp

 Anti-stuttering technology: ??? Pocket-size. Monaural (one ear)? Website: http://www.voiceamp.net Price: US$1850

Personal Experiences Using Defstut
Please read Speech-Language Pathology/Stuttering/How to Participate in this Wikibook before adding material.


text:
Human Physiology/Assignments

Group Assignments
This page is simply to help us keep track of which pages we are editing. Please enter your login id. If you switch groups then let me know and I will update the table. Provophys 17:49, 7 August 2006 (UTC)

title: Human Physiology/Assignments


text: Category:Book:ZK

title: Category:Book:ZK


text: Category:Book:ZZT-OOP

title: Category:Book:ZZT-OOP


text: Category:Book:Waves

title: Category:Book:Waves


text: Category:Book:Zoph

title: Category:Book:Zoph


text: Category:Book:Zulu

title: Category:Book:Zulu


text:
Radiation Oncology/NSCLC/Locally Advanced Unresectable/RT Only

 * See also: Early Stage RT alone (many of these trials included advanced stage patients also)
 * See also: Palliation section

RT vs. Placebo

 * VA Lung Group (VALG) PMID 4170866 -- "The survival of patients with inoperable lung cancer: a large-scale randomized study of radiation therapy versus placebo." (Roswit B, Radiology. 1968 Apr;90(4):688-97.)
 * Randomized. 800 patients. Localized but inoperable KPS 80-100 33%, KPS 50-70 55%, Treated with: 1) RT, 2) placebo, 3) chemo
 * RT: 90% treated with orthovolatage (200-260 kV), 10% with Cobalt-60. Target dose 40-50 Gy, but 33% received <40 Gy
 * Median OS: RT 4.6 months vs. 3.7 months; 1-year survival: RT 18% vs. placebo 14% (p=0.05).
 * Long-term survivors (top 25%): RT 10 monts vs. 7.6 months (SS)
 * Conclusion: RT does not impact median OS, but improves long-term survival

Dose and Fields

 * RTOG Review PMID 16015546 -- "A review of radiation dose escalation trials for non-small cell lung cancer within the Radiation Therapy Oncology Group." (Bradley J, Semin Oncol. 2005 Apr;32(2 Suppl 3):S111-3.)
 * Dose 60 Gy "standard" for the past 30 years; insufficient to control local disease
 * RT alone: 83.8 Gy using 3D-CRT tolerable, 90.3 Gy excess mortality (from RTOG 93-11)
 * RT with chemotherapy: maximum 70-74 Gy

 * RTOG 93-11 (1995–2001) -- dose escalation
 * Phase I/II dose escalation. 176 patients. Stage I-III NSCLC, SCV LN+ excluded ( Prior chemotherapy allowed, concurrent chemotherapy not allowed. 3D treatment planning . GTV = primary tumor and enlarged LN. No elective nodal irradiation. PTV = GTV + 1 cm minimum; verified on fluoroscopy because of breathing motion. Dose prescribed to ICRU reference point within GTV, 93% isodose line to cover PTV, maximum PTV dose <=107%, no heterogeneity correction. Patients grouped based on V20 value using 2.15 Gy/fx:
 * Group 1 (V20 <25%): 70.9/33 -> 77.4/36 -> 83.8/39 -> 90.3/42 (Stage I 53%, Stage III 38%)
 * Group 2 (V20 25-36%): 70.9/33 -> 77.4/36 -> 83.8/39 (Stage I 21%, Stage III 75%) (accrual stopped after 77.4 Gy due to opening of RTOG 0117)
 * Group 3 (V20 >36%): 64.5/30 -> 70.9/33 -> 77.4/36 (accrual stopped after 2 patients)
 * 2005 PMID 15667949 — "Toxicity and outcome results of RTOG 9311: a phase I-II dose-escalation study using three-dimensional conformal radiotherapy in patients with inoperable non-small-cell lung carcinoma." (Bradley J, Int J Radiat Oncol Biol Phys. 2005 Feb 1;61(2):318-28.) Minimum median F/U 13.4 months
 * Acute toxicity: minimal. Group 1 had 9% Grade 3 pneumonitis at 90.3 Gy; Group 2 had 8% Grade 3 pneumonitis at 77.4 Gy. Acute dose-limiting toxicity not reached
 * Late toxicity. Predictors for pulmonary toxicity: mean lung dose, V20
 * Group 1 had 13% Grade 3-5 lung and 6% Grade 3-5 esophageal toxicity (1 death of hemoptysis, 1 death of tracheoesophageal fistula) at 90.3 Gy; tolerable otherwise. Late dose-limiting toxicity at 90.3 Gy level.
 * Group 2 had 16% Grade 3-4 lung toxicity, and 4% esophagus toxicity. Late dose-limiting toxicity not reached.
 * Outcome: 2-year LR 50-78% (but small individual group sizes); LR sole site 18%, component 38%. Elective nodal failure <10%
 * Conclusion: For Group 1 (V20 <25%), 83.8 Gy safe; for Group 2 (V20 25-36%), 77.4 Gy safe using 2.15 Gy/fx
 * RTOG 73-01 (1973–78)
 * 447 pts. Unresectable Stage III (included T3N0). Randomized to 40 Gy split course (20 Gy in one week, 2 weeks rest, then 20 Gy in one week—total 4 weeks), 40 Gy continuous (over 4 weeks), 50 Gy, or 60 Gy. Included tumor + mediastinal + hilar LN. Used spinal cord block to limit dose to cord.
 * PMID 6991092, 1980 (No abstract) — "A prospective randomized study of various irradiation doses and fractionation schedules in the treatment of inoperable non-oat-cell carcinoma of the lung. Preliminary report by the Radiation Therapy Oncology Group." Perez CA et al. Cancer. 1980 Jun 1;45(11):2744-53.
 * PMID 6998937, 1980 (No abstract) — "Patterns of tumor recurrence after definitive irradiation for inoperable non-oat cell carcinoma of the lung." Perez CA et al. Int J Radiat Oncol Biol Phys. 1980 Aug;6(8):987-94.
 * Update (1982): PMID 6286087 (no abstract) — "Impact of irradiation technique and tumor extent in tumor control and survival of patients with unresectable non-oat cell carcinoma of the lung: report by the Radiation Therapy Oncology Group." Perez CA et al. Cancer. 1982 Sep 15;50(6):1091-9.
 * Update (1987): PMID 3032394 — "Long-term observations of the patterns of failure in patients with unresectable non-oat cell carcinoma of the lung treated with definitive radiotherapy. Report by the Radiation Therapy Oncology Group." Perez CA et al. Cancer. 1987 Jun 1;59(11):1874-81.
 * Analysis of RTOG 73-01 and 73-02
 * Conclusion: Determined 60 Gy in 2 Gy/fx to be optimal dose.
 * MGH PMID 6263449 1972-1977 -- "Improved survival of patients with unresectable non-small-cell bronchogenic carcinoma by an innovated high-dose en-bloc radiotherapeutic approach." (Choi NC, Cancer. 1981 Jul 1;48(1):101-9.)
 * Retrospective. 162 patients treated with RT. Initially 40-45 Gy small volume (AP/PA POP), evolved into 60-64 Gy large volume (Ap/PA POP plus AP-RPO-LPO) including regional lymphatics
 * Survival: Median survival independent of dose and volume, long-term (2-year) survival dose and volume dependent (36% vs. 10%). Local control also dose dependent
 * Failure: Squamous cell in primary/regional lymphatics, adeno in brain/bone

Concomitant boost:
 * RTOG 83-12
 * Phase I/II, T3-T4 NSCLC. Concomitant boost at 1.8 Gy/fx to 50.4 Gy (elective nodal). Primary tumor to 2.68 Gy/day to total of 75 Gy in 28 fx.
 * PMID 7860394 (1995)

Hypofractionated

 * QW vs. QD
 * 150 patients (120 evaluable). Locally advanced. Randomized to 1) 60 Gy at 5 Gy x 12 once a week, or 2) 60 Gy at 2 Gy std fractions. Average f/u 3 years
 * Final; 1988 PMID 2839442 -- "Once-a-week vs conventional daily radiation treatment for lung cancer: final report." (Slawson RG, 1: Int J Radiat Oncol Biol Phys. 1988 Jul;15(1):61-8.)
 * Comparable OS: 59% QW vs 49% QD at 1 year, 29% QW vs 23% QD at 2 years. No difference in late toxicity
 * Prelim; 1986 PMID 3519551 (1982–84) — "A prospective randomized trial comparing once-a-week vs daily radiation therapy for locally-advanced, non-metastatic, lung cancer: a preliminary report." Salazar OM et al. Int J Radiat Oncol Biol Phys. 1986 May;12(5):779-87.
 * No difference in outcome.

Hyperfractionation

 * RTOG 81-08 - feasibility study
 * 120 pts. 1.2 Gy BID to 50.4 Gy - 74.4 Gy.
 * Update: PMID 1650526, 1991
 * RTOG 83-11 (1983–87)
 * 848 pts. Unresectable Stage II-IV (without distant mets). 1.2 Gy BID to 60.0, 64.8, 69.6 Gy, 74.4 Gy or 79.2 Gy.
 * PMID 2167952, 1990 — "A randomized phase I/II trial of hyperfractionated radiation therapy with total doses of 60.0 Gy to 79.2 Gy: possible survival benefit with greater than or equal to 69.6 Gy in favorable patients with Radiation Therapy Oncology Group stage III non-small-cell lung carcinoma: report of Radiation Therapy Oncology Group 83-11." Cox JD et al. J Clin Oncol. 1990 Sep;8(9):1543-55.
 * Among 350 pts with good performance status, there was a dose response above 69.6 Gy (median 13.0 months; 2 yr OS 29%) significantly better than lower doses. No dose response above 69.6 Gy.
 * Kraków (Poland) 1992-1996 PMID 10630160 -- "[Radiotherapy for stage III, inoperable, asymptomatic small cell lung cancer. Final results of a prospective randomized study (240 patients)]" - [Article in French]. (Reinfuss M, Cancer Radiother. 1999 Nov-Dec;3(6):475-9.)
 * Randomized. 240 Stage III asymptomatic patients. RT 50/25 vs. split course 20/5 + 20/5 after 4 weeks vs. delayed RT 20/5. No chemo.
 * Median survival: 12 months vs. 9 months vs. 6 months (SS)
 * Conclusion: conventional schedule best

CHART

 * MRC CHART Trial (UK) 1990-1995
 * Stage IA-IIIB (60% Stage III)
 * Randomized 2:1. 563 patients to 1) 54 Gy in 1.5 Gy/fx TID continuously over 12 days vs 2) conventional 60 Gy in 2 Gy/fx over 30 days. No chemo. All non-operable, Stage III 61%, Stage I 30%. 81% Squamous cell.
 * RT: Large volume (tumor, mediastinum, 1 cm margin, ipsilateral hilar LN, paratracheal LN, but not contralateral LN, max AP field 240 cm2) to either 37.5 Gy or 44 Gy, followed by boost (tumor, known LN, 1 cm margin) to 54 Gy or 60 Gy total
 * Mature Update 1999 PMID 10577699 -- "Continuous, hyperfractionated, accelerated radiotherapy (CHART) versus conventional radiotherapy in non-small cell lung cancer: mature data from the randomised multicentre trial. CHART Steering committee." (Saunders M, Radiother Oncol. 1999 Aug;52(2):137-48.)
 * 2-year OS: 30% (CHART) vs. 21% (22% reduction in RR, SS), 3-yr OS 20% vs 13%; Local control 2-yr: 23% vs. 16% (21% reduction in RR, SS), 3-yr: 17% vs 12%. 61% of deaths due to primary tumor, 21% of deaths due to mets.
 * For squamous cell: 2-year OS: 33% vs. 20% (30% reduction in RR, SS), LC 27% reduction in RR
 * No difference in late toxicity
 * 1997: PMID 9250182 — "Continuous hyperfractionated accelerated radiotherapy (CHART) versus conventional radiotherapy in non-small-cell lung cancer: a randomised multicentre trial." Saunders M et al. Lancet. 1997 Jul 19;350(9072):161-5.
 * Dysphagia occurred earlier in CHART, was more severe, but resolved. Severe dysphagia: 19% (CHART) vs 3%.
 * 1996: PMID 8664112 — "Randomised multicentre trials of CHART vs conventional radiotherapy in head and neck and non-small-cell lung cancer: an interim report. CHART Steering Committee." Saunders MI et al. Br J Cancer. 1996 Jun;73(12):1455-62.
 * Conclusion: CHART superior to conventional RT in both 2-year OS and local control


text:
Modern Physics/Page List

This is a page listing for the Modern Physics book. Entries in italics are redirects and can probably be deleted.

title: Modern Physics/Page List


text: Engineering Tables/Table of Derivatives

title: Engineering Tables/Table of Derivatives


text: Engineering Tables/Properties of Derivatives


text: Engineering Tables/Properties of Integrals


text: User:ShakataGaNai

title: User:ShakataGaNai


text:
Nature/Law

What is a law of nature ? Introduction
During history of the human culture and science rules about nature were found and stored. Among those rules there were very simple laws, as for example the sentence:

On earth every held up object falls down to the ground, unless it can fly or it is lighter than air or it is fixed firmly.

Many of these rules were clear to everyone without big thinking: Nearly each human being knew that hungry lions are dangerous. Many of these rules had to be reformulated again and again, since they proved as partly wrong. Some rules were also completely rejected, since they were completely  wrong . A famous example of it was the idea: The earth is the center of the universe and the sun moves around the earth. This idea had to be overcome during a long painful process.

A big improvement in the development of scientific rules was the moment when the scientists started to ask questions and answered them by experiments. The speculations became less and less, the experiments and observations became more and more. Some parts of nature however where out of reach for  experiments , since the objects were too far away or too heavy.

A further improvement was the idea to formulate laws of nature mathematically. In particular physical laws were easily translated to mathematical statements. Chemistry and biology got along quite a time without mathematics.

Each science thus won a refined set of rules in the course of the time. Again and again contradictions emerged, which had to be fitted in.

It turned out that some events in the development of nature could just be described as a  historical  fact, but not as a physical law. Randomness was recognized as factor of influence for such historical events. So it is more or less random, when and where the earth was hit by meteorites and which influence such a meteorite impact on the development of the biological evolution took.

Since the term law of nature suggests safe knowledge, it should be used only critically.

title: Nature/Law


text:
Talk:Nature/Law

Part of this text is copied out of Wikipedia. See http://en.wikipedia.org/wiki/Physical_law As authors are listed among others:
 * Johnstone
 * Plastik
 * Jay
 * Cutler
 * Lexor
 * Tarquin
 * Fredbauder
 * Netesq
 * Seb
 * and many others

title: Talk:Nature/Law


text:
Self Interest and Social Behavior/Smart Choices and Models Based Upon Them

This chapter introduces you to the basics of decision theory and how it can be applied to improve your decisions. It starts with a review of material in Smart Choices, a book written by John Hammond, Ralph Keeney, and Howard Raiffa, experts from the Harvard Business School in the field of decision theory and its application in business. (An MBA program is largely the study of how to improve decisions important to business, and decision theory is a key component of this study.) It continues with a discussion of our goals for models intended to help us predict and explain social behavior. We see that our modeling focuses only upon the most important factors necessary to predict and explain, even if we must sacrifice a complete or accurate description of the individual’s actual decision making process.

Components of a Good Decision
We want the models that we will eventually build throughout this course to help us in predicting and explaining social behavior around us. Since we will be examining a class of models based upon individuals choosing alternatives that promote their self interest, it will be important for us to know what it means exactly for a choice to be rational and to which situations different levels of rationality might fruitfully be applied. To help us understand “rationality” better, to help us in modeling what decisions are actually made, we will first consider advice on improving the rationality of your decisions, or what decisions should be made. How should you decide to best meet your goals? What constitutes a rational choice?

Some decisions in your life will be fairly easy, but most of the important ones will be tough and complex with no obvious choice as the best. Even though a great deal may be at stake, for you and for those around you that you care about, with these tough decisions we risk anxiety from confusion and doubt and the fear of error, regret, and embarrassment. We want to provide you with an anxiety-reducing structure or process to help you with these important, tough decisions.

Find feasible alternatives
Decision theory separates the selection of choices to be considered feasible from how to choose among these choices. It, thus, separates the analysis of what is feasible from the analysis of what is good. Each of these two key steps can also be broken into key components. This divide-and-conquer approach is an important benefit from the use of decision theory. Your assumptions, data, and logic become clear, where they might not be otherwise. As we will see later, separating the analysis of the feasible from analysis of the good is a major benefit from the use of game theory as well.

Ideally, you want to consider all possible feasible alternatives, rank them in order of your preferences, and then choose the best. In practice, the set of all possible alternatives may not be obvious. Further, many feasible options may be clearly sub-optimal, so for simplicity’s sake you might omit them from consideration. Even so, the alternatives in your model represent the range of potential choices you will have for pursuing your objectives. Since you’ll eventually be choosing the best among the alternatives that you consider, make sure that you include all possible best alternatives.

Reconsider the scope of your problem
“A good solution to a well-posed decision problem is almost always a smarter choice than an excellent solution to a poorly posed one.” (16) Be creative about defining your problem; it is often broader than it first appears. The trigger that initiated the decision may suggest a relatively narrow problem, but upon reconsideration you learn that broader issues are involved and should be considered. For example, changes considered to deal with the trigger may open up complementary changes that would not be considered otherwise. (see p.18 for example)

In defining the problem consider the following: What is the trigger? What are the constraints to the problem? What are the essential elements of the problem? What decisions impinge on or hinge upon this decision? Can this problem be broken into smaller parts? After you have asked and answered these questions, talk with others about this problem, either experts that have a similar problem before or non-experts that have your interests at heart. You may gain insight just from your explaining your thinking, as well as from any advice itself.

Crafting an appropriate definition takes time, and it often can’t be done effectively in one sitting. Like the crafting of an introductory paragraph for a Freshman Studies paper, the problem definition often needs reworking as the body is developed. Like that introductory paragraph, keep revisiting it as your analysis proceeds. Reconsidering the problem definition is especially important when circumstances change rapidly or new information becomes available. Remember, if you have an inappropriate problem definition, at best, you may go very fast—but in the wrong direction.

 * use your objectives and work backwards — ask “how?” :Make sure that each of the constraints that limit your alternatives is real. If not, eliminate it. Even if they are real, can you find any ways around these constraints?
 * challenge constraints :Make sure that each of the constraints that limit your alternatives is real. If not, eliminate it. Even if they are real, can you find any ways around these constraints?
 * set aspirations high :“One way to increase the chance of finding good, unconventional alternatives is to set targets that seem beyond reach.” (51) Start with an alternative with a great outcome, but one that is also infeasible, and then modify it to make it feasible.
 * give your subconscious time to operate :Your mind doesn’t work just by direct attack. If you start on the problem early, you give yourself time to be reconsidering the problem in a “low” mode while doing something else (a shower? drifting off to sleep? working on another problem?). Sometimes good ideas come. Start early and give yourself the chance.

learn from others
Find out what you and others have done in similar situations. What lessons do you learn from these other situations? What could have been done better?

Others may be able to provide some insights from earlier experience with similar situations or they may suggest new paths that you haven’t considered. Also, keep an open mind during your conversations with others. The primary benefit may not be the specific ideas that others provide, but simply the insights that you gain from organizing your thoughts into explanations and from answering questions.

At the same time, talking with others first may limit you to their framework of the problem. Think about the problem first yourself, since you may find a new approach.

consider more alternatives

 * consider process alternatives :Especially when you need to justify your choice to others or have their approval, the best alternative may be a process for making a choice, rather than the choice itself. Could you use a voting mechanism? an auction? set standards that would then be applied after gathering more information?
 * search for win-win alternatives :Again, especially when you need to justify your choice to others or have their approval, you should consider alternatives that make them better off as well as you. Put yourself in their shoes, and ask yourself how they might choose. Create alternatives where you both win.
 * consider information-gathering alternatives :You may be dealing with important uncertainties. You might want to gather more information that would reduce this uncertainty. Another possibility is a choice that allows you to defer a complete decision that may allow you to gather useful information. Remember, though, that deferring a decision may mean other alternatives may disappear, and thus, have a price. (Consider how to deal with uncertainties and whether to gather more information with Chapters 7-9.)

For the most part you want to generate as many alternatives as possible to evaluate later. Be careful not to eliminate seemingly bad alternatives if they might be transformed into good ones. Even alternatives with a fatal flaw might be modified to eliminate the flaw and yield an exceptional candidate. Also, throughout the decision-making process keep looking for alternatives.

At the same time, some balance is needed here in considering new alternatives. You don’t want to spend time, money, and energy if there is no potential payoff. The model of your decision does not need to include all possible alternatives that may be taken—just all the possible best ones. Is the time, effort, and energy of this decision-making process with it? How much value and how much cost is likely to come from the extra effort?

Choose best among the feasible
Now that you’ve considered your decision problem and the alternative choices available to you, what do you really want to achieve? What are your goals? You need to know these goals to be able to evaluate your various alternatives.

a procedure for uncovering your objectives

write down all your concerns that you hope to address through your decision convert your concerns into succinct objectives; use short phrases with verb and object (e.g. maximize profit, raise chance of re-election, reduce pollution) separate ends from means to establish your fundamental objectives; these fundamental objectives will be used to evaluate the alternatives clarify what you mean with each objective test your objectives against several alternatives; are they consistent with your underlying feelings?

understand the consequences of each alternative
From the choice of any alternative will come consequences, first the physical consequences, and then the consequences in terms of all of the objectives of your decision problem.

 * Describe the physical consequences with appropriate accuracy, completeness, and precision
 * Describe the consequences in terms of each of the objectives with a consequences table
 * as much as possible, experience the consequences — try before you buy
 * use common scales as much as possible
 * use scales with the appropriate level of precision
 * don’t rely exclusively on hard data; subjective assessments are important too
 * make the most of available information
 * use experts wisely; understand their assumptions as well as their conclusions
 * address uncertainty head on

eliminate dominated alternatives
With two alternatives, if the first is better in some objectives and no worse in any, the second alternative cannot be the best choice, and thus, can be eliminated. In the job example below, Job B is better than Job E with four objectives and equal with two. Therefore, eliminate Job E.

make tradeoffs clearer by subtracting equals
In any comparison, since we are looking for differences to determine which is best, we can eliminate anything of equal value from all columns. We change the decision problem by substituting components of equal value, and then focus on differences, ignoring all parts of the outcomes that are of equal value. In the job example, we may eliminate $1800 of salary, health benefits, and 10 vacation days from all columns.

Try to subtract the most easily identified equals first. When evaluating the differences, is there a common scale for some of the objectives? When the difference in the number of vacation days is small, one additional vacation day may be worth $100 to Vincent. This would then mean that the monthly salary and vacation days rows can be combined by adding the salary and the value of the extra vacation days. With this change, Job A dominates Job D, and Job D can be eliminated.

Similarly, Vincent can hire someone to be with his ill father for those times that he could not be with him for $100 per month to make up the difference between low and high work schedule flexibility. After swapping $100 plus low flexibility for Job B with high flexibility for Job C, we find Job B now dominates Job C, and Job C can be eliminated.

Now all that remains of Vincent’s decision problem is to choose between Job A and Job B. Vincent needs to decide if the higher enjoyment, retirement benefits, and extra work schedule flexibility is worth more or less than an extra $400 in salary and better skill development. Vincent determines that the retirement benefits and extra work schedule flexibility are worth $200, so he must compare whether the remainder, the higher enjoyment with A is worth more or less than an extra $200 in salary and better skill development.

Often subtracting the most easily identified equals will allow enough alternatives to be eliminated that difficult tradeoffs may not be necessary to establish. Sometimes not, though. The tradeoffs may remain difficult. Unfortunately, no matter what choice you make, you are implicitly placing a value on these tradeoffs. You might as well confront the choices directly. Following the procedures above allows you to simplify your decision-making problem as much as possible to allow you to better understand the tradeoffs that you must face in your decision.

Modeling Behavior as Rational Decisions
Now we want to shift our focus. Instead of examining how some person should make a decision, we want to examine what decisions people actually make. We are most interested in predicting and explaining decisions that we see made in some social behavior of interest. To do this, we want to construct a model that incorporates the most important features of some social behavior of interest that would help us predict and explain what we see. In doing this, we are certainly willing to sacrifice a complete description of some people, their environment, or the resulting behavior, if we can describe in as simple a way as possible what will happen and why.

Create models that predict and explain behavior
One must always remember that a model is not intended to describe the fullness of actual behavior. It is only a stripped down version of the real thing, but one designed to determine how important factors influence observed behavior. The modeler consciously includes only those factors that he feels are most important. Especially at the beginning of an investigation, he keeps the model extremely simple. Once the effect of those few factors of an early model are understood, then he includes another to determine its effect, then another, and then another. To test the resulting logic, he adds and subtracts various factors, and applies his new models to various environments. And he compares his predicted results to actual choices made in similar environments. But even at the end, factors that at times may have some influence over some behavior may be left out. For the questions asked, these factors may add nothing of importance in predictive power and, in their inclusion, add such difficulty to obscure the essence of an appropriate explanation. These factors should not ever be included; the simplifying assumptions that omit these factors are to be encouraged. Note that a model that predicts and explains best always remains a simplified version of the world; it is not intended to be a description of the real thing.

Keeping a model simple not only improves the model's ability to explain, it also reduces the probability that mere chance explains the success of the model. A more parsimonious model, one that is more concise and simple, is more likely to be correct. We seek models that have parsimony.

A model with power, one that explains a large number of phenomena, also reduces the probability that mere chance explains the success of the model. A model with more power is more likely to be correct. We seek models that have more power.

 * What one generation of scientists knows, beyond any shadow of doubt, with a knowledge that is built into the very fabric of their world, is precisely what the succeeding generation will challenge and overturn. If you know something that strongly, you don't question it. If you don't question it, you're living by faith, not by science. — Ian Stewart

At the same time, these models are not used within a vacuum. Each discipline shares common views and assumptions that they find most useful for making progress in their discipline. Some of the disciplines that study social behavior share paradigms based upon models of individuals furthering their own self interest. Some do not.

An objective of this course is to demonstrate that, compared to other views that could be used in each discipline that studies social behavior, models of individuals furthering their own self interest appear to predict observed behavior reasonably well in many contexts, they seem to explain why this behavior is occurring relatively simply and with great power. These models have sufficiently wide applicability that they may offer a common paradigm for the study of all social behavior. For especially those disciplines where practioners do not now generally share this view, much work is needed to test this view against others and to reassess which views are likely to be the most useful for making progress in these disciplines. For these disciplines, we may be in the midst of paradigmatic revolution.

All models are wrong, but some are useful if . ..
As would be expected if texts are needed to teach people how to make rational decisions, many actual decisions are made that do not meet the standards of a rational choice model. “Virtually no one believes that anything approximating such a procedure is observed in any individual or organization. . . for any number of. . . decision tasks that confront them. . . . Pure rationality strains credulity as a description of how decisions actually happen.” (March, 1994, 5)

In many actual decisions, we find (March, 1994, 8-9):
 * Instead of considering all alternatives simultaneously, some decision makers appear to consider only a few of these alternatives and then look at them sequentially.
 * Some decision makers do not consider all of the consequences of their alternatives: they focus on some and ignore others.
 * Relevant information about consequences is not sought, and available information is often not used.
 * Some decision makers implicitly use preferences that are incomplete and inconsistent.
 * Some decision makers don’t choose their best alternative possible, but choose a choice that is good enough.

To make models more consistent with these concerns, modern decision theory sometimes modifies the rational choice model by changing the knowledge of the decision makers, the number of decision makers, loosening the restrictions on their preferences, or changing the decision rules that they use. Most importantly, they allow limited rationality. With this limited rationality, decision makers intend to be rational, but they are constrained by limited cognitive capabilities and incomplete information, and thus their actions may be less than completely rational, at least when compared to those that would be selected with costless decision making, in spite of their best intentions and efforts. The internal costs of making a decision lead them to decide in ways inconsistent with the rational choice model that does not include these internal costs.

Are these differences important for our purposes? Sometimes, sometimes not. For three reasons (or for combinations of these three reasons), the rational choice model can still remain appropriate.

In some decisions, the rational choice model may model the decision making process quite well. When a great deal is at stake, when the decision making environment is one in which the decision maker has a great deal of experience, and when the decision making environment is relatively simple, decisions may be made rationally. For these situations, certainly, the rational choice model is perfectly appropriate to predict and to explain observed behavior. Determining the situations to which this model applies then becomes a critical question.

In some other decisions, even when a decision maker does not decide as the rational choice model describes, she may act as if she does. For example, as a driver of an automobile, she may not know or understand all of the mechanics and physical forces at work in her car. Nevertheless, she has learned that when she moves her hands and feet in certain ways in certain situations, the car reacts in certain ways. With experience, she still may choose actions that maximize consistent preferences as if she understood all of this knowledge. The rational choice model would be perfectly appropriate to predict behavior in such situations. At the same time, it may be less valuable at explaining what is happening. The appropriateness of this model would then depend upon why we want to use it.

In other decisions, the rational choice model may not even be able to predict individual decisions very well, but aggregate behavior or average behavior may be quite accurate. For example, for some economic good, the quantities demanded by some individual consumers in this market may not always match the predictions from the rational choice model, but the aggregate over all consumers, the market demand, may be quite accurate. Some consumers may choose a bit more than the model predicts, while others choose a bit less, so that the aggregate is quite accurate. If our concern is this aggregate or average behavior, the rational choice model is useful. A more complete, limited rationality model may allow the observed “noise” around the rational-choice prediction, but if introducing this limited rationality doesn’t introduce any bias in the central tendency, the greater simplicity of the rational choice model may be valuable itself.

Remember that formal models have two purposes: We want to use them both to predict and to understand behavior under specified circumstances. These two purposes also have conflicting needs. Prediction usually improves if more and more factors that have any impact at all are included within the model. Understanding usually improves if fewer factors are included within the model. The goal then is to include only those factors that have an important effect without significantly changing the reasons behind the prediction. This means we always want to include any assumption that omits a factor that does not change the prediction of the model, a simplifying assumption, but for other assumptions, how "important" the effect has to be and how "significant" a change in the reasons behind the prediction for some factor to be included within the model depends upon the questions to be asked of it.

In any event, we will return later to consider how observed behavior sometimes does not match up with the predictions from our rational choice models. We reconsider situations where rational choice models seem more likely to apply, and how this might alter the models that we might want to use and when we might want to use them. Also, since we will be examining social behavior in many different contexts, we will look for similarities across many different types of social behavior. As a first attempt, we will assume that when reasonable people who have the same goals are put into similar situations, they tend to make similar choices.