1. You are recording an action potential from
an unidentified nerve. Which of the following is true?
A. By looking at the shape of the action potential you can determine
that you are recording from a motor neuron.
B. The action potential is a graded potential C.* You can not distinguish the type of nerve you are
recording from by looking at the action potential.
D. You can only recorded action potentials from glial cells.
E. No two action potentials would ever look the same. 2. During an action potential the following events
occur.
A. Voltage gated sodium channels open and sodium flows out of
the cell.
B. Voltage gated sodium channels open and sodium flows into the
cell.
C. Voltage-gated potassium channels open and K flows out to repolarize
the cell.
D. Both A. and C. occur E.* Both B. and C. occur 3. Synaptic transmission occurs between a neuron
and another neuron, or a muscle or a gland. Which statement about
synaptic transmission is incorrect?
A. Most synaptic transmission is chemical.
B. In chemical synapses the synaptic cleft is 20 nm and is the
distance a neurotransmitter must diffuse.
C. Receptors on the post synaptic cell determine if a response
is excitatory or inhibitory. D.* Calcium is not needed for synaptic transmission.
E. It is important to remove a neurotransmitter from the synaptic
cleft after it has been used for synaptic transmission. 4. You are studying synaptic transmission by recording
from a post-synaptic neuron. Under control conditions you stimulate
the presynaptic neuron and record an EPSP in the post-synaptic
cell. You have discovered a new compound from an exotic rain forest
plant that prevents the fusion of synaptic vesicles with the presynaptic
membrane. How will this drug affect your recordings?
A. There will be no effect.
B. You will now record an IPSP. C.* You will record no post synaptic potential.
D. You will enhance the size of the EPSP.
E. You will increase the duration of the EPSP. 5. In class we discussed three organizing principles
for understanding nervous systems: divergence, convergence and
reflex arcs. Which of the following statements is true?
A.* In convergence a target cell receives the sum of information
from many presynaptic cells. B. In divergence a target cell receives the sum of information
from many presynaptic cells.
C. A reflex arc involves many responses to sensory stimuli. It
involves the brain and complex processing.
D. Interneurons are basically sensory neurons and have receptors
that interact directly with the environment.
E. None of the above (A. - D.) is true. 6. Myelin has the following function.
A.* It helps increase the speed at which an action potential
travels. B. It prevents the neuron from heating up after an action
potential.
C. Neurotransmitters are synthesized in the myelin.
D. Myelin has no known function.
E. The voltage-gated sodium channels that underlie an action potential
are located in the myelin. 7. Rod, cone and ganglion cells are involved in
which sensory system.
A. Chemoreception
B. Mechanoreception C.* Photoreception D. Thermoreception
E. Pain reception 8. All sensory systems have a common plan. Which
statement about sensory systems is incorrect?
A. Receptor potentials are graded.
B. Sensory systems can adapt.
C. The strength of a stimulus is encoded in the frequency of the
action potentials it produces. D.* The strength of a stimulus is encoded in the size
of the action potentials it produces. E. Sensory receptors detect changes in a stimulus. 9. Steroid and nonsteroid hormones are similar
because they both
A. activate genes that lead to the synthesis of new proteins.
B. bind with receptors on the plasma membrane of target cells.
C. use second messengers to activate enzymes in the cytoplasm
of target cells. D.* are chemical messengers that are distributed to non-adjacent
target cells by the circulatory system.
E. B. and C. both make correct statements. 10. Parathyroid glands secrete a hormone, PTH,
that stimulates bone cells to release calcium and also activates
vitamin D which enhances calcium absorption from ingested food.
From your general understanding of the control of hormone secretion,
which one of the following statements is most likely to be correct?
A. PTH release is stimulated when bones grow too large.
B. The secretion of PTH is inhibited when bones lose too much
calcium.
C. According to the principle of negative feedback control, PTH
secretion is stimulated when the calcium concentration in the
blood drops below normal, homeostatic levels. D.* According to the principle of negative feedback control,
PTH secretion is inhibited when the calcium concentration of the
blood increases above normal levels.
E. Parathyroid glands require iodine to function properly. 11. Which of the following statements is(are) true?
A. The posterior pituitary peptides oxytocin and ADH are neurohormones
secreted by hypothalamic neurosecretory cells.
B. Endocrine cells in the anterior pituitary secrete releasing
hormones that act on other endocrine glands.
C. A special portal system carries releasing hormones from the
hypothalamus to the anterior pituitary. D.* A. and C.
E. B. and C.
[Note: A. was also accepted for version 0 of the exam, since
the textbook does not define the term "portal."]
12. The medulla of the adrenal gland develops
from neural tissue. In response to a "threatening" situation,
cells of the adrenal medulla produce ______ and secretion is controlled
by ______.
A. cortisol; ACTH (adrenocorticotropic hormone) B.* epinephrine (adrenaline) and norepinephrine; sympathetic
nerves. C. cortisol; ACh (acetylcholine)
D. epinephrine and norepinephrine; ACTH
E. ACTH; ACh 13. _____ muscle tissue occurs in the walls of
many internal organs except the heart.
A. Skeletal
B. Cardiac C.* Smooth D. Striated
E. Autonomic 14. According to the sliding filament model of
muscle contraction,
A.* if a resting muscle fiber is "overstretched"
so that its thin and thick filaments do not overlap at all, the
sarcomeres cannot contract when the muscle fiber stimulated. B. thick and thin filaments shorten up to 70% during
sarcomere contraction.
C. cross bridges that form between adjacent myosin molecules provide
the energy that causes actin filaments to shorten.
D. thin filaments slide past thick filaments during sarcomere
contraction because troponin molecules push the Z lines towards
each other.
E. myosin heads attach to actin binding sites and bend in a power
stroke that pulls thin filaments away from the center of the sarcomere. 15. The ATP needed for contraction of skeletal
muscle during prolonged, moderate exercise
A. is provided mainly by an anaerobic pathway (lactate fermentation)
in which glucose is broken down to lactate.
B. is provided mainly by aerobic respiration.
C. is derived first from the breakdown of glucose that comes from
the glycogen stored inside the muscle fibers, and later from glucose
and fatty acids delivered by the bloodstream.
D. is derived mainly from the dephosphorylation of creatine phosphate. E.* both B. and C. make correct statements. 16. Blood provides an internal bulk transport
system that carries nutrients, gases and waste products from sites
of absorption or production to sites of utilization or excretion.
It is composed of water, solutes (including proteins and ions),
cells, and formed elements. What is not found in blood?
A. hormones
B. glucose
C. antibodies D.* glycogen E. platelets 17. In humans a blood cell initially found in the
right pulmonary vein will encounter which part of the circulatory
system next?
A. left ventricle
B. capillary in the right lung
C. right pulmonary artery D.* left atrium E. right atrium 18. When one listens to the heart with a stethoscope,
two main heart sounds can be heard, lub-dup, which repeat rhythmically
[...lub-dup...lub-dup...lub-dup...etc.]. The first heart sound,
lub, is low-pitched, not very loud, and fairly long-lasting. It
is caused mainly by the _______, and marks the beginning of _______.
A. closing of the semilunar valves (aortic and pulmonary valves);
ventricular systole B.* closing of the AV valves; ventricular systole C. closing of the AV valves; ventricular diastole
D. contraction of the ventricles; ventricular systole
E. closing of the semilunar valves; ventricular diastole 19. The lymphatic system picks up excess fluid
from the tissues and removes unwanted biota and cellular debris
from the lymph. Where does the "excess fluid" come from?
A. It is produced in the bone marrow.
B. It is secreted by tissue cells.
C. It is absorbed across the wall of the small intestine whenever
we take a drink of water. D.* It leaks out of the capillaries due to hydrostatic
pressure of the blood. E. It is pulled out of the capillaries due to the high
osmotic pressure of the interstitial fluid. 20. When we inhale,
A.* the size of our thoracic (chest) cavity increases
due to contraction of our respiratory muscles. B. the pressure within the lungs is less than the pressure
within the thoracic cavity.
C. our diaphragm contracts causing it to move upward and become
more curved.
D. all the oxygen in the air in our alveoli diffuses into our
blood.
E. all of the above (A. - D.) make correct statements 21. Rate and depth of breathing in humans is controlled
by respiratory centers in the reticular formation of the brain
that signals our breathing muscles to contract and relax. The
respiratory centers receive input from sensory receptors that
monitor . They cause us to breath faster and more deeply .
A. our heartrate; whenever our heartrate increases
B. the concentration of O2 in our blood; when the partial pressure
of O2 in our lungs declines C.* the concentration of hydrogen ions in our blood; when
the pH of our blood declines D. the partial pressure of CO2 in our blood; when the
concentration of H2CO3 (carbonic acid) in our blood declines
E. blood pH; when blood pH increases 22. Which of the following statements regarding
gas exchange and transport in humans is (are) true?
A.* Carbon dioxide in metabolically active tissue diffuses
into the blood because the partial pressure of carbon dioxide
is higher in the tissue fluid than in the blood entering the capillaries. B. Carbon dioxide diffuses into the blood because its
partial pressure is greater at the start of the systemic capillaries
than at the start of the systemic veins.
C. Most of the oxygen carried in the blood to body tissues is
bound to red blood cell membranes.
D. Almost all of the carbon dioxide transported in the blood is
either dissolved in plasma or bound to hemoglobin.
E. C. and D. 23. The pancreas is an accessory organ of the digestive
system that
A. secretes insulin and glucagon into the digestive tract to aid
in the breakdown of polysaccarides.
B. secretes enzymes into the digestive tract that help break down
all major food macromolecules.
C. secretes bicarbonate into the small intestine to neutralize
HCl from the stomach. D.* B. and C. make correct statements E. A., B. and C. all make correct statements 24. Most enzymatic digestion takes place in the
A. mouth (oral cavity)
B. stomach C.* small intestine D. large intestine
E. liver 25. Products of the digestive process such as monosaccarides
and amino acids, are absorbed in the _____ by means of active
transport or facilitated diffusion and pass into ______ . Triglycerides
are reassembled inside intestinal cells, are packaged into chylomicrons
and enter ______.
A. stomach; blood capillaries; the lymph system B.* small intestine; blood capillaries in intestinal villi;
lymph vessels in the villi C. stomach; the small intestine; blood capillaries in
intestinal villi
D. large intestine; blood capillaries; lymph vessels
E. villi; the interstitial fluid; blood capillaries in microvilli