Dr. Davis’s 1QQs Physiology Fall 2011

1. Dr. Davis’s 1QQs Physiology Fall 2011

2. 1QQ # 2 Name on top edge, back side of paper Answer on blank side of paper.If the statement is true, mark it true. If false, replace the underlined word to make it a true statement. • For the negative feedback loop for thermoregulation • The hypothalmus is an afferent pathway • Somatic nerves are the efferent pathway to sweat glands • Skeletal muscle tone would be increased as a response to a drop in core body temperature • Peripheral nerves are the afferent pathway that convey skin temperature information • Cutaneous arterioles would dilate in response to a drop in core body temperature.

3. 1QQ # 3 8:30 Section • Which of the following are true during the absorptive phase? (Circle all correct responses.) • Amino acids are taken up by muscle tissue. • The liver converts glucose to a-ketoacids. • Muscle cells polymerize glucose to glycogen. • Excess amino acids are converted to triglycerides in the liver in a multi-stop enzymatic process • As plasma glucose levels rise, so does the secretion of insulin. • Adipose tissue converts excess glucose to triglycerides. • Almost all cells use glucose as metabolic fuel. • 1 a b c d e f g

4. 1QQ # 3 9:30 Section • Which of the following are true during the absorptive phase? (Circle all correct responses.) • Amino acids are released by muscle tissue. • The liver converts glucose to a-ketoacids. • Muscle cells polymerize glucose to glycogen. • Excess amino acids are converted to triglycerides in the liver in a multi-stop enzymatic process • As plasma glucose levels rise, secretion of insulin is diminished. • Triglycerides enter adipose tissue cells. • Almost all cells use fatty acids as their main metabolic fuel. • 1 a b c d e f g

5. 1QQ # 4 8:30 am • What changes in hepatocyte metabolism are produced by glucagon? • A) What advise would you give to a person who is a reactive hypoglycemic and B) provide the reasons for your advise. • Your patients plasma glucose level is 45 mg/dl. A) What hormone is responsible for her rapid heart rate, pale clammy skin, and irritability? B) Why does she have a headache?

6. 1QQ # 4 9:30 am • Explain in some detail how beta cells of the Islets of Langerhans are affected by anticipating an excellent meal. • A) Describe a situation that would lead to the activation of the sympathetic nervous system. B) How does sympathetic stimulation affect the secretion from beta cells in the Islets of Langerhans? C) Why is this beneficial for the person in terms of fuel supply? • After an overnight fast, a patient arrives for an Oral Glucose Tolerance Test. The first blood sample (even before ingestion of the Tru-Glu cola shows a plasma glucose concentration of 150 mg/dl. A) Do you have the patient drink the Tru-Glu? Why or why not? B) What might you do next to determine what is “wrong” with your patient?

7. 1QQ # 5 for 8:30 Each True/False Question counts 2 points. Answer all five. • Epinephrine is an amine hormone. • If you don’t know which category a hormone belongs to, the best guess is “peptide.” • The thyroid hormones and steroid hormones have intracellular receptors and affect gene expression and have long-lasting effects in their target cells. • All amine and peptide hormones are transported in the plasma in two forms: bound and free. • Thyroid hormones and steroid hormones are stored in vesicles and secreted later.

8. 1QQ # 5 for 9:30 Each True/False Question counts 2 points. Answer all five. • Dopamine is an amine hormone. • If you don’t know which category a hormone belongs to, the best guess is “steroid.” • The thyroid hormones and steroid hormones have cell-surface receptors and usually have long-lasting effects in their target cells. • T3 and T4 and peptide hormones are transported in the plasma in two forms: bound and free. • Catecholamines and peptide hormones are stored in vesicles and secreted later.

9. 1QQ # 6 for 8:30 Write the number of the one question you choose to answer. • TSH stimulates • The thyroid gland to take up iodide • the synthesis and secretion of thyroglobulin • The uptake of thyroglobulin from the colloid • Follicular cells of the thyroid gland to grow • The hypothalamus to secrete more TRH. OR • In response to a drop in blood pressure • Juxtaglomerular cells of the kidney secrete less renin • Elevated levels of aldosterone stimulate thirst • Newly-formed angiotensin I causes vasoconstriction • Elevated levels of aldosterone promote Na+ retention by the kidneys • The liver produces more Angiotensin II.

10. 1QQ # 6 for 9:30 Write the number of the one question you choose to answer. • TSH stimulates • The thyroid gland to take up iodide • the synthesis and secretion of thyroglobulin • The uptake of thyroglobulin from the colloid • Its target cells to incorporate more Na+/K+ ATPase into their membranes • The hypothalamus to secrete more TRH. OR • In response to a drop in blood pressure • Juxtaglomerular cells of the kidney secrete less renin • Elevated levels of Angiotensinogen stimulates thirst • Newly-formed angiotensin I causes vasoconstriction • Elevated levels of aldosterone promote Na+ retention by the kidneys • The liver produces more Angiotensin II.

11. 1QQ # for 8:30 Write the number of the one question you choose to answer. 1) Suppose the portal vessel that connects the median eminence to the adenohypophysis was completely occluded (blocked.)  Which hypothalamic hormone(s) could not reach their target cells? a) ACTH   b) CRH   c) DA    d) Prolactin      e) TRHf) TSH g) FHS     h)  T3      i) GnRH     j) ADH OR 2A Name the hormone normally secreted by hepatocytes. 2B Name the hormone secreted by cells in the adenohypophysis that stimulates the secretion of the “liver” hormone. 2C Suppose liver cells form a tumor that secretes the “liver” hormone in an unregulated manner. Assuming cells in the adenohypophysis are behaving normally, would the levels of the tropic hormone from the anterior pituitary be normal, high, or low?

12. 1QQ # for 9:30 Write the number of the one question you choose to answer. 1) Suppose the portal vessel that connects the median eminence to the adenohypophysis was completely occluded (blocked.)  Which hypothalamic hormone(s) could not reach their target cells? a) Oxytocin   b) Prolactin   c) DA    d) CRH      e) TRHf) TSH g) FHS     h)  T3   i) GnRH     j) ADH OR 2 Cells in the anterior pituitary gland that secrete TSH a) have receptors for TRH in their cell membranesb) can sense the levels of T3 and T4 in the plasmac) will release more TSH as levels of TRH rise d) Should release less TSH after a person has been treated with radioactive iodine e) Should release less TSH if a person is dosed with exogenous TH.

13. 1QQ # 8 for 8:30 1) A woman presents with elevated plasma levels of ACTH and Cortisol. Which other symptoms are expected: • Low levels of plasma fatty acids • Heightened resistance to infection • High blood pressure • Enlargement of facial bones and hands and feet • Random episodes of intense sweating with no apparent “trigger.”

14. 1QQ # 8 for 9:30 1) During a visit with her physician, a woman complains of random episodes of intense sweating with no apparent “trigger,” high susceptibility to infection, and very irregular menstrual cycles. She has elevated blood pressure ( 140/90) and elevated levels of fatty acids in her plasma. You realize these symptoms are characteristic of • menopause • acromegaly • Primary adrenal insufficiency • Hypercortisolemia • Primary hypothyroidism.

15. 1QQ # 9 for 8:30 class • A) List the four categories of glia cells of the central nervous system and B) state which category you would choose to eliminate from your CNS if you were forced to do so, being sure to C) give your reasons for your selection. • A) Describe the location and purpose of a growth cone and B) how axonal transport is associated with growth cones.

16. 1QQ # 9 for 9:30 class • A) List the four categories of glia cells of the central nervous system and B) state which category you would choose to eliminate from your CNS if you were forced to do so, being sure to C) give your reasons for your selection. • A) Describe the location and purpose of a growth cone and B) how axonal transport is associated with growth cones.

17. 1QQ # 10 for 8:30 class • At resting membrane potential • The concentration gradient favors the entry of Na+ • The electrostatic driving force favors the entry of Na+ • The concentration gradient favors the exit of K+ • The electrostatic driving force favors the exit of K+ • The membrane is more permeable to Na+ than to K+. • Suppose you have a cell with the normal concentrations of Na+ and K+ on either side of the membrane, and you were able to make the membrane absolutely and completely impermeable to Na+. A) What would the membrane potential be? (include the units.)B) What equation would you use to calculate the membrane potential?

18. 1QQ # 10 for 9:30 class • At the equilibrium potential for Na+ • The concentration gradient favors the entry of Na+ • The electrostatic driving force favors the entry of Na+ • The concentration gradient favors the exit of K+ • The electrostatic driving force favors the exit of K+ • The membrane is more permeable to Na+ than to K+. • Suppose you have a cell with the normal concentrations of Na+ and K+ on either side of the membrane, and you were able to make the membrane absolutely and completely impermeable to K+. A) What would the membrane potential be. (include the units.)B) What equation would you use to calculate the membrane potential?

19. 1QQ # 11 for 8:30 class • Why doesn’t an action potential reach + 60 mV? • Voltage- gated Na+ channels open and spontaneously close quickly • Voltage-gated K+ channels open a little later than the Na+ channels • Na+ K+ ATPase quickly pumps out the Na+ that enters during an AP • As the membrane approaches +60 mV, the driving force for Na+ entry is weaker • Na+ is not the only permeable ion. • Which are the accurate statements regarding V-gated K+ channels? • The more the membrane is depolarized, the more K+ channels will open, and the membrane will depolarize even more, generating a positive feedback cycle. • These channels inactive after a short open time and can only reopen if the membrane potential returns to negative values. • These channels are “blocked” by lidocaine, xylocaine, and novocaine. • These channels close as the membrane repolarizes.

20. 1QQ # 11 for 9:30 class • Why doesn’t an action potential reach + 60 mV? • Voltage- gated Na+ channels would be forced “shut” at + 60 mV • Voltage-gated K+ channels open a little sooner than the Na+ channels. • Na+ K+ ATPase quickly pumps out the Na+ that enters during an AP • As the membrane approaches +60 mV, the driving force for Na+ entry is weaker • Na+ channels open only briefly and then quickly inactivate. • Which are the accurate statements regarding V-gated K+ channels? • The more the membrane is depolarized, the more K+ channels will open, and K+ will leave the cell, contributing to repolarization. • These channels inactive after a short open time and can only reopen if the membrane potential returns to negative values. • These channels are “blocked” by lidocaine, xylocaine, and novocaine. • These channels open shortly after the V-gated Na+ channels open.

21. 1QQ # 12 for 8:30 class • Which could cause a larger response in a post-synaptic cell? • Keep V-gated Ca++ channels open longer in the presynaptic cell • Very high frequency of action potentials in the presynpatic cell • Block the reuptake of neurotransmitter from the synpatic cleft • Enhance the reuptake of neurotransmitter from the synaptic cleft into the presynaptic cell or astrocytes • Block the action of enzymes in the synpatic cleft that degrade neurotransmitters. • Which are CORRECT concerning chemical synapses? • Chemical synapses are bi-directional. • Chemical synapses are ideally suited to synchronize the activity of many cells. • Chemical synapses are far more common than electrical synapses in the CNS of humans. • Chemical synapses depend upon the influx of Ca++ to releaseneurotransmitters. • At a chemical synapse, the response of the post-synaptic cell is invariable.

22. 1QQ # 12 for 9:30 class • Which could cause a smaller response in a post-synaptic cell? • Keep V-gated Ca++ channels open longer in the presynaptic cell • Very high frequency of action potentials in the presynapatic cell • Increase the reuptake of neurotransmitter from the synapatic cleft • Enhance the reuptake of neurotransmitter from the synaptic cleft into the presynaptic cell or astrocytes • Block the action of enzymes in the synapatic cleft that degrade neurotransmitters. • Which are CORRECT concerning chemical synapses? • Chemical synapses are unidirectional. • Chemical synapses are ideally suited to synchronize the activity of many cells. • Chemical synapses are far less common than electrical synapses in the CNS of humans. • Chemical synapses depend upon the influx of Ca++ to releaseneurotransmitters. • At a chemical synapse, the response of the post-synaptic cell is invariable.

23. 1QQ # 13 for 8:30 class • Which will activate muscarinic acetylcholine receptors? • acetylcholine • nicotine • muscarine • curare • atropine. • Nicotinic acetylcholine receptors • Are metabotropic receptors. • Can be activated with nicotine. • Can be activated with acetylcholine. • Can be blocked with muscarine. • Can be activated with atropine.

24. 1QQ # 14 for 8:30 class • Pain and temperature information • Is carried in the spinothalamic tract • Is carried in the dorsal column/medial lemniscal tract • Crosses (decussates) in the spinal cord • Is relayed to the somatosensory cortex via 3rd order neurons in the thalamus • Is carried in the anterolateral tract. • Which are true of touch and proprioception pathways? • Second order neurons are located in the dorsal column nuclei • Axons of first order neurons travel in the spinothalamic tract • Axons of first order neurons decussate (cross the midline) in the spinal cord • Axons of second order neurons travel in the medial lemniscus. • Axons of first order neurons ascend in the dorsal columns and synapse onto second order neurons in the dorsal column nuclei.

25. 1QQ # 13 for 9:30 class • Which will block muscarinic acetylcholine receptors? • acetylcholine • nicotine • muscarine • curare • atropine. • Muscarinic acetylcholine receptors • Are metabotropic receptors • Can be activated with nicotine • Can be activated with acetylcholine • Can be blocked with muscarine • Can be activated with atropine.

26. 1QQ # 14 for 9:30 class • Pain and temperature information • Is carried in the anterolateral tract • Is carried in the dorsal column/medial lemniscal tract • Crosses (decussates) in the medulla • Is relayed to the somatosensory cortex via 3rd order neurons in the thalamus • Is carried in the spinothalamic tract. • Which are true of touch and proprioception pathways? • First order neurons are located in the dorsal column nuclei • Axons of first order neurons travel in the spinothalamic tract • Axons of first order neurons decussate (cross the midline) in the spinal cord • Axons of second order neurons travel in the medial lemniscus. • Axons of first order neurons ascend in the dorsal columns and synapse onto second order neurons in the dorsal column nuclei.

27. 1QQ # 15 for 8:30 class • Why would you insist that an epidural injection of lidocaine not be given in the region of cervical vertebra? • Describe the challenges that face neuroscientists who wish to replace dying or damaged neurons in the brain with cells donated from elsewhere. • You suspect that the neurons in Nucleus X are communicating with their target cells by releasing NE as their neurotransmitter. Describe an experiment that would allow you to test your hypothesis. • Use your knowledge of cortical neuroanatomy to explain why stroke victims very often have deficits involving the face and hands.

28. 1QQ # 15 for 9:30 class • Describe the challenges that face neuroscientists who wish to replace dying or damaged neurons in the brain with cells donated from elsewhere. • You suspect that the neurons in Nucleus Z are communicating with their target cells by releasing ACh as their neurotransmitter. Describe an experiment that would allow you to test your hypothesis. • Use your knowledge of cortical neuroanatomy to explain why stroke victims very often have deficits involving the face and hands.

29. 1QQ # 16 for 8:30 class • Which of the following are correct statements: a) Most sympathetic postganglionic axons release NE.b) Most parasympathetic postganglionic axons release ACh.c) the urinary bladder will relax if exposed to ACh.d) axons of parasympathetic neurons are found in thoracic and lumbar spinal nerves. e) NE and EPI can cause contraction of arterioles. • Which of the following are correct statements: a) Most sympathetic preganglionic axons release NE.b) Most parasympathetic postganglionic axons release ACh.c) intestinal motility and secretion will increase as parasympathetic activity increases. d) The vagus nerve provides parasympathetic innervation to the rectum and urinary bladder. e) Smooth muscles of arterioles have adrenergic and mucarinic receptors.

30. 1QQ # 16 for 9:30 class • Which of the following are correct statements: a) Sympathetic preganglionic axons use NE as their neurotransmitter.b) Most parasympathetic postganglionic axons release ACh.c) the urinary bladder will contract if exposed to NE.d) Some cranial nerves have preganglionic sympathetic axons. e) Smooth muscles and glands typically have adrenergic and muscarinic receptors. • Which of the following are correct statements: a) Most sympathetic preganglionic axons release NE.b) Most parasympathetic postganglionic axons release ACh.c) intestinal motility and secretion will increase as parasympathetic activity increases. d) The vagus nerve provides parasympathetic innervation to the rectum and urinary bladder. e) Smooth muscles of arterioles have adrenergic and mucarinic receptors.

31. 1QQ # 17 for 8:30 class • Which of the following are correct statements: a) The intensity of a stimulus is proportional to the size of the graded potential in the receptive membrane.b) The modality of a stimulus is encoded by which type or types of sensory receptors are activated. c) The intensity of a stimulus is encoded by the frequency of action potentials. d) Some ascending spinal neurons receive synaptic inputs from more than one part of the body. e) Each taste receptor cell has at least two different categories of tastant receptor proteins. • What is the meaning of labeled line in the context of sensory physiology?

32. 1QQ # 17 for 9:30 class • Which of the following are correct statements: a) The intensity of a stimulus is proportional to the size of the generator potential.b) The modality of a stimulus is encoded by which type or types of sensory receptors are activated. c) The intensity of a stimulus is encoded by the frequency of graded potentials. d) Some ascending spinal neurons receive synaptic inputs from skin and internal organs. e) Each hair receptor cell has mechanically-gated and voltage-gated ion channels. • What is the meaning of the term “adequate stimulus” and what is the adequate stimulus for a taste receptor cell?

33. 1QQ # 18 for 8:30 am A B C D Four first-order sensory neurons with receptive membranes at bottom. 1. If the stimulus is applied at the black bar, which sensory neuron will have the highest frequency of action potentials and why? 2. If the stimulus is applied at the black bar, which sensory neuron will have the lowest frequency of action potentials and why? 3. What happens at the region of the membrane indicated by the arrow? Stimulus

34. 1QQ # 18 for 9:30 am Consider the four second-order sensory neurons (A- D) across the top of the diagram. Assume there are interneurons arranged in a typical pattern that interconnects these neurons. A C B D 1. If the stimulus is applied at the black bar, which 2nd order neuron will have the highest frequency of action potentials and why? 2. If the stimulus is applied at the black bar, which 2nd order neuron will have the lowest frequency of action potentials and why? Stimulus

35. 1QQ # 19 Write a question that you were prepared to answer today and provide the answer to that question. A more challenging/sophisticated/thought-provoking question with its correct answer earns more points than a simple memorization-type question.

36. 1QQ # 20 for 8:30 section Answer one question. • Which are characteristics of Slow-Oxidative myofibers? • Abundant capillaries nearby • ATP is hydrolyzed relatively quickly • Abundant glycogen • Abundant myoglobin • Belong to large motor units. 2. Name the three classes of skeletal myofibers and indicate which type isbest suited to serve as a postural muscle and why.

37. 1QQ # 20 for 9:30 section Answer one question. • Which are characteristics of glycolytic myofibers? • Abundant capillaries nearby • ATP is hydrolyzed relatively quickly • Abundant glycogen • Abundant myoglobin • Belong to large motor units. 2. Would a marathon runner benefit from supplementing with creatine? Why or why not?

38. 1QQ # 21 for 8:30 section Answer one question. • Which are characteristics of cardiac myofibers? • Ca++ for excitation-contraction coupling originates fromintracellular and extracellular sources • Cardiac myofibers have a twitch duration longer than smooth myofibers. • Produce action potentials that allow the influx of Ca++ for more than 100 ms. • Conduct action potentials to neighboring cells via gap junctions of intercalated disks • Produce tension in proportion to the amount of cytosolic Ca++. 2. What type of myofiber can enter a latch state and what are the advantagesof the latch state?

39. 1QQ # 21 for 9:30 section Answer one question. • Which are characteristics of multi-unit smooth myofibers? • Each myofiber is individually innervated by autonomic neurons • Can be excited or inhibited by somatic motoneurons • Often have pacemaker potentials that result in periodic contractions • Are found in the walls of small-diameter blood vessels • Belong to large motor units. 2. Which properties of smooth muscle cells make them much better suited for their role in the walls of hollow organs than skeletal myofibers?

40. 1QQ 27 for 8:30 • Beginning with a loss of 1 liter of blood, diagram the sequence of events that leads to a change in the frequency of action potentials in baroreceptors. (No abbreviations allowed.)

41. 1QQ 27 for 9:30 • Beginning with a loss of 1 liter of blood, diagram the sequence of events that leads to a change in the frequency of action potentials in baroreceptors. (No abbreviations allowed.)

42. 1QQ 28 for 8:30 • What is the partial pressure of oxygen in atmospheric air at sea level? What about in the alveolus? What are these values not identical? • Which has the highest partial pressure of oxgyen and why: pulmonary arterial blood, pulmonary venous blood, system arterial blood? • How are bronchioles and arterioles similar?

43. 1QQ 28 for 9:30 Inspiration is an “active” event whereas a normal expiration is a “passive” event. What does this mean in terms of muscle activity, and what is responsible for expiration if muscles aren’t contracting? How would you calculate the partial pressure of oxygen in the atmosphere at the summit of Mt. Everest? How are arterioles and bronchioles similar?

44. 1QQ 29 for 8:30 • For a given bronchopulmonary segment, by what mechanism is blood flow (Q) matched to air flow (V)? • What is the location and function of goblet cells?

45. 1QQ 29 for 9:30 Describe how a person’s ventilation would be affected if he had a severely reduced amount of cartilage in the wall of his airways. Suppose a region of the lung has very little air flow (V). How is blood flow (Q) affected to that region, and by what mechanism is this accomplished? What is a treatment for obstructive sleep apnea?

46. 1QQ 30 for 8:30 What would alveolar minute ventilation be in a person who is breathing 10 breaths per minute and has a typical tidal volume and typical dead space volume? Show your work. Suppose a 25 year old man were unable to produce sufficient levels of surfactant. Would he have difficulty inhaling? Exhaling? Why or why not?

47. 1QQ 30 for 9:30 What would alveolar minute ventilation be in a person who is breathing 20 breaths per minute and has a typical tidal volume and typical dead space volume? Show your work. Why do prematurely born infants have difficulty inhaling but not exhaling?

48. 1QQ 31 for 8:30 What is the partial pressure of oxygen in the tissues surrounding systemic capillaries and list three conditions lower the affinity of hemoglobin for oxygen as it passes through these systemic capillaries. At what arterial partial pressure of oxygen does ventilation steeply increase in response to further drops in PO2. Why is this so? Why aren’t the central chemoreceptors stimulated by lactic acid when metabolism increases?

49. 1QQ 31 for 9:30 What is the partial pressure of oxygen in the tissues surrounding systemic capillaries and list three conditions lower the affinity of hemoglobin for oxygen as it passes through these systemic capillaries. At what arterial partial pressure of oxygen does ventilation steeply increase in response to further drops in PO2. Why is this so? What are the several roles of hemoglobin?

50. 1QQ 32 for 8:30 What evidence indicates that the abrupt increase in ventilation at the onset of exercise is not the result of negative feedback? Why is the negative feedback system more sensitive to changes in PaCO2 than PaO2? How is it that hyperventilating immediately before diving allows a pearl diver to hold his breath for a longer interval that he would otherwise be able to?