1. For EITHER smooth endoplasmic reticulum or Golgi apparatus, say ONE function.

steroid synthesis, detoxifying (liver microsomal fraction), calcium ion cistern

2. In an equivalent circuit of the axon membrane, in ADDITION to batteries and resistors, what other component is found (hint, the component that changes voltage as a function of time).

capacitors

3. What affect does cortisol have on the anterior pituitary gland?

negative feedback, inhibit ACTH release

4. "Cells of an exocrine gland release their product into a duct." Where do cells of an endocrine gland release their product?

the blood stream (capillaries)

5. "The capillary beds in the hypothalamus and anterior pituitary are 'wired' together in series; there are similar systems in the kidney and connecting the intestine with the liver." What is the term used for this kind of blood vessel or system?

portal vessel

6. Thyroid gland (answer either) (1) Who would have an enlarged thyroid gland? OR (2) What is that enlarged thyroid gland called?

someone deficient in dietary iodine, goiter

7. For rhodopsin, what is it that turns the otherwise colorless protein into a pigment?

retinaldehyde, the aldehyde of vitamin A is the chromophore

8. "You can see two sides of the membrane in transmission electron microscopy and you can see membrane proteins with the freeze fracture technique." Well, that's obviously an oversimplification. What is it that actually creates the electron density?

heavy metal, osmium, platinum, lead, uranium

9. Say one of the things that needed to be done to make phospholipids show up on an audioradiogram of a thin layer chromatography plate.

label them with radioactive phosphate, expose film

10. In terms of the biochemical constituents of the cell membrane, answer either (1) Why do membranes have high resistance? or (2) Despite the high resistance, why is there at least some conductance across the membrane?

hydrophobic interior fatty acids, channels

11. Describe the trick to record the electrical current from a single nicotinic acetylcholine receptor.

put a patch clamp electrode up against the channel

12. What membrane protein uses energy derived from ATP to move sodium and potassium ions across the cell membrane?

sodium pump = sodium potassium pump = Na+K+ATPase

13. "At the axon hillock (the beginning of the axon), there is a decision as to whether there is enough net excitation to fire off an action potential." If there were an excitatory graded potential at the dendrite, why might there not be enough net excitation at the hillock?

maybe there was also an IPSP, also EPSP spreads decrementally

14. Cole and Curtis showed that the resistance decreased during the action potential. What happens to what channels to mediate this resistance decrease?

conductance increases, sodium channel first, then potassium channel (channels open, activate)

15. Although it is close to the truth, and very useful in the derivation of the Nernst equation, in what way was the equilibrium assumption not completely true?

ions do flow down their concentration gradient when the channel is open even though electrical potential should be equal and opposite to chemical gradient

16. In the equivalent circuit of the Goldman equation, why are the chloride vs sodium batteries in reverse polarity even though their ion gradient is the same (high outside, low inside)?

because sodium is a cation and chloride is an anion

17. "You can't have more current flowing into one place than flows out of that place," is my casual wording of one of (whose?) laws that applies to circuits.

Kirchoff

18. An axon goes past a cell body, called a pseudounipolar neuron. That cell body is located in the dorsal root ganglion near the spinal cord. In the knee-jerk reflex, answer ONE of the following: (1) What kind of information is carried in this axon? OR (2) What does this nerve cell connect to?

stretch of muscle, spinal motor neuron

19. In the peripheral nervous system, the action potential... (answer either) (1) jumps from one (fill in the blank) to the next OR (2) in other words, it jumps past (what?).

node of Ranvier, Schwann cell = patch of myelin

20. "Each spinal motor neuron connects to a whole bunch of muscle cells called a motor unit." In Halstead's paper on post-polio syndrome, how is this connectivity affected (answer either) (1) during recovery after polio strikes, OR (2) later in life when symptoms get bad again?

1-more muscle cells per muscle unit supported by surviving axons, 2 extra sprouts are lost

21. Why did Sherrington use the word "final" when he referred to the spinal motor neuron as the "final common pathway in the integrative action of the nervous system?"

since yhe motor end plate only has excitation, there can be no integration further out (at the neuro-muscular junction)

22. How did calcium ions become available to bind to the synaptic vesicle protein synaptotagmin?

they came in through the voltage gated calcium channel at the terminal upon arrival of the action potential

23. "Vagus-stuff slows the heart." Answer one of the following. (1) What major subdivision of the autonomic nervous system does vagus-stuff come from? (2) What chemical is vagus-stuff?

parasympathetic, acetylcholine

24. Why is it NOT correct to refer to acetylcholine as an agonist or an antagonist?

those terms are for drugs, not the real transmitter

25. Why would you die if your acetylcholinesterase were inhibited?

too much acetylcholine would stop the heart

26. Vesicle membrane is retrieved. Answer either (1) What is this process, cell drinking, called? OR (2) What do these pits that pinch off to vesicles look like in the electron microscope?

pinocytosis or endocytosis, they are called "coated" because a fuzzy coat of clathrin is electron dense

27. Norepinephrine is a neurotransmitter, and it is, chemically, an amine. In it's biosynthetic pathway, name one of the precursors or one of the enzymes.

tyrosine tyrosine hydroxylase l-DOPA dopa decarboxylase dopamine dopamine beta hydroxylase

28. In contrast with the mechanism to terminate cholinergic transmission (involving acetylcholinesterase) what keeps norepinephrine or epinephrine from stimulating the receptor forever?

reuptake

29. "Caffeine potentiates the 'upper' action of epinephrine and norepinephrine by..." answer either (1) inhibiting the breakdown of what molecule? OR (2) inhibiting what enzyme?

cAMP, PDE

30. Some cranial nerves are part of the autonomic nervous system. Which subdivision of the autonomic nervous system?

parasympathetic (cranio-sacral)

31. There are acetylcholine receptors that are channels. In addition, there are acetylcholine receptors that are G protein-coupled receptors that are called (what?), named on the basis of pharmacology.

muscarinic

32. For both branches of the autonomic nervous system, an axon exits the central nervous system and makes a synapse in a ganglion. What is the receptor for the neurotransmitter in the ganglion?

nicotinic

33. Why would an alpha-1 adrenergic agonist be useful as a nasal decongestant?

mediate vasoconstriction

34. Why is a muscle weaker when it is fully extended than when it is shorter?

less overlap of actin and myosin

35. ATP binds to what muscle protein?

myosin

36. Reducing calcium ions in the extracellular fluid bathing the neuromuscular junction would do (what?) to the vesicle release?

decrease (to 0, 1, or 2 per nerve impulse)

37. For myasthenia gravis, answer either (1) Why do the patients experience muscular weakness? OR (2) What would be given to help the patient?

to few nicotinic channels, neostigmine (acetylcholinesterase inhibitor)

38. A channel to what ion mediates the action potential of the T tubules?

calcium

39. Say something (else) about the properties of the type of muscle fiber that is sometimes called fast twitch.

white meat, anaerobic, strong but not enduring

40. What is the difference in stimulation that makes the force bumpy in incomplete tetanus (as opposed to complete tetanus)?

incomplete -> complete as the frequency of nerve stimulations goes up

41. Give a source of muscle energy other than glucose and glycogen.

fat, fatty acids

42. MLCK (myosin light chain kinase) [answer either] (1) does what to myosin light chain? OR (2) functions in what kind of muscle? OR (3) functions to activate what process?

phosphorylates it, cross bridge activation, contraction

43. There is an axon terminal that releases acetylcholine at the neuromuscular junction. By contrast, what is the geometry of neurotransmitter release from the postganglionic neuron in the autonomic nervous system as smooth muscle is activated or inactivated?

varicosities like beads on a string

44. What is so special about carbon that makes it the common denominator of all organic molecules?

it makes 4 bonds

45. What molecule (or what kind of molecule) is the precursor of prostaglandins, mediators of inflammation?

arachidonic acid, a polyunsaturated fatty acid

46. Urea is created (answer either) (1) to get rid of what waste? Which is created because (2) what kind of molecule is being used by catabolism for energy?

ammonia (nitrogen), amino acids

47. Answer either: (1) Under what circumstances do you create lactic acid to regenerate NAD? or (2) What is the immediate precursor from which lactic acid is made?

when aerobic metabolism is not sufficient, pyruvic acid

48. By activation of the beta adrenergic receptor in the liver cell, adenylate cyclase must chop (what? and how much?) off of ATP as cAMP is made.

two phosphates

49. Energy is ultimately needed when sodium ions "drive" a co-transporter for glucose, but not by this transporter molecule. Where is energy used?

by the sodium pump

50. "The third phosphate of ATP is is not just broken off as inorganic phosphate, but is actually delivered to a molecule." Regarding the action of the insulin receptor, what molecule acquires phosphate from ATP?

the receptor is phosphorylated at a tyrosine residue (then other cascade molecules)

return to syllabus

return to stark home page