MCQ-Physiology-ANS PDF

## ANS **DIRECTIONS** (Questions 1 through 172): Each of the numbered items or incomplete statements in this section is followed by answers or by completions of the statement. Select the ONE lettered answer of completion that is BEST in each case. 1. The brain and spinal cord comprise the: a...

## ANS **DIRECTIONS** (Questions 1 through 172): Each of the numbered items or incomplete statements in this section is followed by answers or by completions of the statement. Select the ONE lettered answer of completion that is BEST in each case. 1. The brain and spinal cord comprise the: a) Central nervous system. b) Peripheral nervous system. c) Peripheral ganglia. d) Spinal nerves. 2. Autonomic motor nerves do NOT innervate: a) Smooth muscle. b) Skeletal muscle. c) Cardiac muscle. d) Glands. 3. Which of the following is the correct sequence in a typical reflex arc: a) Receptor, afferent neuron, efferent neuron, integration center, effector. b) Effector, efferent neuron, integration center, afferent neuron, receptor. c) Receptor, afferent neuron, integration center, efferent neuron, effector. d) Receptor, efferent neuron, integration center, - afferent neuron, effector. 4. The following reflexes are all autonomic EXCEPT: a) Micturition. b) Defecation. c) Salivary secretion. d) Flexion of the arm following a painful stimulus. 5. Preganglionic autonomic fibers are of: a) Type A (alpha). b) Type A (delta). c) Type B. d) Type C. 6. --------fibers have relatively slower nerve conduction because they are thin & unmyelinated. a) Preganglionic autonomic sympathetic. b) Postganglionic autonomic sympathetic. c) Preganglionic somatic. d) Postganglionic somatic. 7. The autonomic nervous system: a) Is always excitatory. b) Innervates skeletal muscle. c) Is not usually under conscious control. d) Has a single nerve extending from the spinal cord. 8. All of the following characterize the ANS EXCEPT: a) A two-neuron efferent chain. b) Innervation of skeletal muscles. c) Presence of neuron cell bodies in the CNS. d) Presence of neuron cell bodies in the ganglia. 9. Which of the following is a characteristic of the somatic nervous system? a) It operates under voluntary control. b) It secretes both acetylcholine and norepinephrine. c) It innervates glands, smooth muscle, and cardiac muscle. d) It consists of two nerve fibers that synapse at a ganglion before reaching a target organ. 10. The paravertebral and collateral ganglia are associated with the -------- division of the autonomic nervous system. a) Parasympathetic. b) Sympathetic. c) Somatic. d) Sensory. 11. Parasympathetic ganglia are located: a) In the brain. b) In the dorsal roots of spinal nerves. c) In a chain parallel to the spinal cord. d) Next to or within the organs innervated. 12. The autonomic ganglia: a) Are 5 types. b) Are located inside the CNS. c) Are the site of relay of afferent neurons. d) Function as distributing centers. 13. Concerning the autonomic ganglia, all the following is true EXCEPT: a) They are 3 types. b) They acting as distributing centers. c) Their chemical transmitter is acetyl choline. d) Their receptors are specifically blocked by atropine. 14. The autonomic ganglia have all the following characters EXCEPT: a) Are sites of relay of autonomic preganglionic and postganglionic fibers. b) Are three types: lateral, collateral and terminal. c) Are all present adjacent to the spinal cord. d) Are functioning as distributing centers. 15. The sympathetic preganglionic nerve fibers: a) Originate at the autonomic ganglia. b) Show minimal divergence in the autonomic ganglia. c) Leave the spinal cord in the grey rami communicantes. d) Are myelinated nerve fibers belonging to the B group of nerve fibers. 16. What occurs when one sympathetic preganglionic neuron synapses on several postganglionic neurons? a) Convergence. b) Cooperation. c) Divergence. d) All apply. 17. The neurotransmitter released at terminal ganglia is: a) Acetylcholine. b) Norepinephrine. c) Epinephrine. d) Dopamine. 18. The parasympathetic division of the autonomic nervous system: a) Has long postganglionic neurons. b) Has relatively short preganglionic neurons. c) Has a single neuron arising from the spinal cord. d) Has terminal ganglia embedded in the visceral effectors. 19. The sympathetic division of the autonomic nervous system (ANS) is characterized by: a) Short postganglionic fibers. b) Adrenergic preganglionic fibers. c) Localized actions affecting few systems. d) Thoracolumbar outflow from the spinal cord. 20. Which of the following is a feature of the sympathetic, but NOT the parasympathetic nervous system? a) Long preganglionic neurons. b) Ganglia located in the effector organs. c) Preganglionic neurons release acetylcholine (A Ch). d) Preganglionic neurons originate in the thoracolumbar spinal cord. 21. The effects of sympathetic and parasympathetic fibers are cooperative in: a) The eyes. b) The heart. c) The genital system. d) The digestive system. 22. All the following structures are supplied by sympathetic system only EXCEPT: a) Skin. b) Adrenal medulla. c) Ventricles of the heart. d) Constrictor pupillae muscle. 23. A tissue innervated only by the sympathetic division is the: a) Heart. b) Urinary bladder. c) Gastrointestinal tract. d) Blood vessels of skeletal muscle. 24. Which of the following organs receive both sympathetic & parasympathetic: a) Lungs. b) Sweat glands. c) Adrenal medulla. d) Ventricular cardiac muscle. 25. The white ramus communicans contains: a) Preganglionic sympathetic fibers. b) Postganglionic sympathetic fibers. c) Preganglionic parasympathetic fibers. d) Postganglionic parasympathetic fibers. 26. The gray ramus communicans contains: a) Somatic motor fibers. b) Parasympathetic motor fibers. c) Sympathetic preganglionic fibers. d) Sympathetic postganglionic fibers. 27. The preganglionic sympathetic that innervate the eye originate from: a) Ciliary ganglion. b) Superior colliculi. c) Superior cervical ganglion. d) Thoracic segments of spinal cord. 28. Horner's syndrome results from a lesion involving: a) Pelvic nerve. b) Vagus nerve. c) Lumbar spinal cord. d) Superior cervical ganglion. 29. A lesion in the cervical sympathetic chain (Horner's syndrome) causes: a) Increased sweating. b) Mydriasis (dilatation of the pupil). c) Dropping of the upper eyelid (ptosis). d) Vasoconstriction of the skin blood vessels (leading to pallor). 30. All of the following about Horner's syndrome is true EXCEPT: a) Causes pallor of skin due to VC. b) Manifested by dryness & redness of skin. c) Group of signs including ptosis & miosis. d) Is due to injury of LHCs present in thoracic 1-2 spinal segments. 31. Postganglionic sympathetic starting from cervical and upper four thoracic ganglia causes: a) Dilatation of the coronary vessels. b) Contraction of the splenic capsule. c) Narrowing of the respiratory passages. d) Secretion of the adrenomedullary hormones. 32. Stimulation of sympathetic to abdomen produces: a) Increased motility of the plain muscles of the stomach. b) Excessive secretion of the gastric juice by the stomach. c) Decreased blood levels of both glucose & free fatty acids. d) Secretion of epinephrine & norepinephrine by the adrenal medulla. 33. Stimulation of sympathetic to abdomen produces: a) Inhibition of micturition. b) Increased motility of the stomach. c) VC of the blood vessels in the erectile tissue. d) Increased blood level of both glucose & catecholamines. 34. Stimulation of sympathetic to abdomen produces: a) Decreased blood volume. b) Increased blood glucose level. c) Increased gastrointestinal motility. d) Secretion of epinephrine 20% & norepinephrine 80% from adrenal medulla. 35. Stimulation of sympathetic to abdomen produces all the following EXCEPT: a) Increased blood glucose level. b) Decreased gastrointestinal motility. c) Increased gastric and pancreatic secretions. d) Secretion of catecholamines from the suprarenal medulla. 36. Which of these does NOT result from sympathetic stimulation? a) Piloerection. b) Digestive secretion. c) Dilation of the pupil. d) Acceleration of the heart. 37. Stimulation of sympathetic to pelvis causes: a) Erection. b) Ejaculation. c) Micturition. d) Defecation. 38. Choose the correct statement: a) Sympathetic supply to the lungs causes bronchoconstriction. b) Sympathetic nervous system supplies every organ in the body. c) Stimulation of sympathetic to abdomen results in adrenomedullary secretion. d) Postganglionics starting from the superior cervical ganglion causes constriction of the pupils. 39. Choose the correct statement: a) Sympathetic supply to the lungs causes bronchodilatation. b) Sympathetic nervous system supplies every organ in the body. c) Stimulation of sympathetic to pelvis results in adrenomedullary secretion. d) Postganglionics starting from the superior cervical ganglion causes constriction of the pupils. 40. Increased activity of the sympathetic nervous system causes: a) Penile erection. b) Pupillary constriction. c) Bronchiolar dilatation. d) Accommodation for near vision. 41. Stimulation of the sympathetic nervous system causes: a) Bronchoconstriction. b) Decreased glycogenolysis & lipolysis. c) Generalized actions affecting many systems. d) Contraction of the ciliary muscle for near vision. 42. Activation of sympathetic nervous system causes: a) Sweat secretion. b) Pupillary constriction. c) Cutaneous vasodilatation. d) Bradycardia (decreased heart rate). 43. Generalized sympathetic stimulation causes: a) Inhibition of sweating. b) Increased gastric motility. c) Decreased blood sugar levels. d) Increased arterial blood pressure. 44. Activation of sympathetic nervous system produces the following EXCEPT: a) Bronchodilatation. b) Mydriasis (dilatation of pupil). c) Tachycardia (increased heart rate). d) Contraction of detrusor muscle of urinary bladder wall. 45. The alarm response is accompanied by all of the following, EXCEPT: a) Rise of blood glucose level. b) Pupillo-dilatation (mydriasis). c) High level of circulating adrenaline. d) Hypotension (decreased arterial blood pressure). 46. The sympathetic response in fight reaction causes an INCREASE in all the following, EXCEPT: a) The size of the pupil. b) The resistance of airways. c) The arterial blood pressure. d) Blood glucose concentration. 47. During the fight reaction, the following effect takes place: a) Bradycardia. b) Dilatation of the pupil. c) Decreased blood flow to the skeletal muscle. d) Increased motility of the gastrointestinal tract. 48. The sympathetic supply CAN'T be responsible for: a) Erection of hair. b) Bronchodilatation. c) Constriction of the pupil. d) Dilatation of skeletal muscle blood vessels. 49. Concerning adrenal medulla, all the following is true EXCEPT: a) It acts only in emergency conditions. b) It is a modified sympathetic ganglion. c) It receives postganglionic sympathetic nerve supply. d) It secretes epinephrine 80% and norepinephrine 20%. 50. The parasympathetic nerves: a) Are catabolic in their actions. b) Are important in emergency conditions e.g. fight & flight reactions. c) Generally, exert opposite effects to those of the sympathetic nerves. d) Tend to have longer postganglionic fibers than preganglionic fibers. 51. Which of the following statements is NOT true? a) Sympathetic origin is craniosacral; parasympathetic is thoracolumbar. b) Sympathetic ganglia are within a few centimeters of the CNS; parasympathetic are close to visceral organs served. c) Sympathetic division has short preganglionic and long postganglionic fibers; parasympathetic has long preganglionic and short postganglionic fibers. d) Sympathetic has extensive branching of preganglionic fibers; parasympathetic has minimal branching of preganglionic fibers. 52. Over 90% of all parasympathetic fibers are derived from cranial nerve number: a) V. b) VII. c) X. d) XII. 53. Salivary secretion increases on stimulation of: a) Vagus nerve. b) Trigeminal nerve. c) Hypoglossal nerve. d) Glossopharyngeal nerve. 54. Brain swelling from a head injury can compress this nerve and interfere with the ability of the pupils to react to light. a) Optic. b) Facial. c) Olfactory. d) Oculomotor. 55. Contraction of ciliary muscle during accommodation of the eye for near vision is controlled by: a) Optic nerve. b) Trochlear nerve. c) Oculomotor nerve. d) Sympathetic fibers that reach the eye. 56. The functions of parasympathetic innervation to the salivary glands are: a) VC & secretion. b) VD & secretion. c) VD & inhibition of secretion. d) Secretion of scanty viscid saliva. 57. All of the following organs receive their parasympathetic innervation via the vagus nerves EXCEPT: a) Gall bladder. b) Atria of the heart. c) Proximal half of large intestine. d) Distal half of large intestine. 58. Parasympathetic functions include all of the following, EXCEPT: a) Dilation of the airways. b) Constriction of the pupils. c) Stimulation of urination. d) Stimulation of defecation. 59. Vagal stimulation causes: a) Tachycardia (increased heart rate). b) Dilatation of the bronchi and bronchioles. c) Increase in gastric and pancreatic secretion. d) Inhibition of plain muscles in stomach and small intestine. 60. Disorders involving the vagus nerve might cause: a) Increased sweating. b) A drop in blood pressure. c) Constriction of the pupils. d) Food to remain in your stomach longer. 61. Stimulation of the pelvic nerve (sacral autonomic) causes: a) Stoppage of prostatic secretion. b) Contraction of the bronchial muscle. c) VD of the blood vessels in the external genitalia. d) Contraction of the internal urethral & anal sphincters. 62. Stimulation of the pelvic nerve (sacral autonomic) produces: a) Ejaculation of semen. b) Relaxation of the wall of rectum. c) Contraction of the urinary bladder wall. d) VC of the blood vessels in the external genitalia. 63. Concerning the pelvic nerve (sacral autonomic), all the following is true EXCEPT: a) It is the nerve of erection. b) It is motor to the wall of gall bladder. c) It is inhibitory to both the internal anal & urethral sphincters. d) It is motor to the wall of urinary bladder & distal half of large intestine. 64. All of the following about pelvic nerve (sacral autonomic) is true EXCEPT: a) It is the nerve of defecation. b) It is the nerve of micturition. c) It is the nerve of ejaculation. d) It relays in terminal ganglia. 65. Concerning the cranial parasympathetic outflow: a) They cause bronchodilatation. b) They contract the wall of gall bladder & relax the sphincter of Oddi. c) Preganglionic outflow in the oculomotor nerve arises from the ciliary ganglion. d) Preganglionic outflow in the glossopharyngeal nerve arises from superior salivary nucleus. 66. Which one of the following statements concerning the parasympathetic nervous system is CORRECT? a) It controls the secretion of the adrenal medulla. b) It uses norepinephrine (NE) as a neurotransmitter. c) It is involved in accommodation of near vision, movement of food, and urination. d) Its postganglionic fibers are long compared to those of the sympathetic nervous system. 67. Which of the following may be produced by parasympathetic stimulation? a) Dilatation of the pupil. b) Acceleration of the heart. c) VD of skeletal muscle blood vessels. d) Contraction of the urinary bladder wall. 68. Which of the following is one of the actions of the parasympathetic division of the autonomic nervous system? a) Increases heart rate. b) Stimulates sweat glands. c) Inhibits intestinal motility. d) Constricts bronchial tubes. 69. Which of these is NOT a neurotransmitter in the autonomic nervous system? a) Muscarine. b) Epinephrine. c) Acetylcholine. d) Norepinephrine. 70. Acetylcholine (ACh) is secreted at all the following sites EXCEPT: a) Preganglionic sympathetic nerve terminals. b) Postganglionic parasympathetic nerve terminals. c) Postganglionic sympathetic adrenergic nerve terminals. d) Postganglionic sympathetic nerve terminals at skeletal muscle blood vessels. 71. The neurotransmitter of preganglionic sympathetic fibers is: a) Dopamine. b) Epinephrine. c) Acetylcholine. d) Norepinephrine. 72. The neurotransmitter at the neuromuscular junction is: a) Dopamine. b) Epinephrine. c) Acetylcholine. d) - Norepinephrine. 73. All preganglionic axons of the autonomic nervous system release: a) Dopamine. b) Adrenaline. c) Noradrenaline. d) The same transmitter as the one released by parasympathetic postganglionic axons. 74. Cholinergic fibers include all the following EXCEPT: a) Somatic motor nerve fibers. b) Sympathetic nerve fibers to adrenal medulla. c) Postganglionic nerve fibers to dilator pupillae muscle. d) Sympathetic & parasympathetic preganglionic nerve fibers. 75. Which of the following statements concerning the preganglionic neurons of the ANS is TRUE? a) All sympathetic preganglionic neurons secrete norepinephrine. b) All parasympathetic preganglionic neurons secrete acetylcholine. c) Only sympathetic preganglionic neurons secrete norepinephrine. d) Only parasympathetic preganglionic neurons secrete acetylcholine. 76. Which of the following statements CORRECTLY describes cholinergic fibers? a) Cholinergic fibers secrete acetylcholine. b) Cholinergic fibers secrete norepinephrine. c) Cholinergic fibers include the preganglionic fibers of the parasymp. division only. d) Cholinergic fibers include the postganglionic fibers of the symp. and parasymp. divisions. 77. About acetylcholine, all the following is true EXCEPT: a) Inactivated by cholinesterase enzyme. b) It is synthesized in the adrenal medulla. c) Released by all postganglionic parasympathetic nerves. d) Released by the sympathetic cholinergic postganglionic nerve fibres. 78. About acetylcholine, all the following is true EXCEPT: a) It is broken down enzymatically by the cholinestrase enzyme. b) It makes reading difficult because of relaxation of the ciliary muscle. c) It is the chemical transmitter released by the preganglionic nerve fibers. d) It is synthesized & released by some sympathetic postganglionic nerve fibers. 79. About acetylcholine, all the following is true EXCEPT: a) Its muscarinic action can be blocked by atropine. b) Its nicotinic actions can be blocked by large doses of nicotine. c) It is not secreted by any sympathetic postganglionic nerve fibers. d) Its synthesis is catalyzed by the choline acetyltransferase (CAT) enzyme. 80. Muscarine-like action of acetyl choline is present in all the following EXCEPT: a) Somatic neuromuscular junction. b) Parasympathetic postganglionic nerve endings to the heart. c) Sympathetic postganglionic supplying the eccrine sweat glands. d) Sympathetic postganglionic supplying the skeletal muscle blood vessels. 81. Acetylcholine action at the autonomic ganglia is: a) Nicotine like action. b) Muscarinic like action. c) Blocked by atropine. d) Blocked by muscarine. 82. Nicotinic receptors: a) Are blocked by atropine. b) Are found in sympathetic ganglia. c) - Are not sensitive to accetylcholine. d) Accept nicotine released by nerve endings near the receptor. 83. Throughout the autonomic nervous system, the neurotransmitter released by the preganglionic fiber binds to --------receptors on the postganglionic neuron. a) Nicotinic. b) Muscarinic. c) Beta adrenergic. d) Alpha adrenergic. 84. The receptors found at synapses between preganglionic and postanglionic neurons of the sympathetic system are: a) Nicotinic. b) Muscarinic. c) Beta adrenergic. d) Alpha adrenergic. 85. Which autonomic receptor mediates secretion of epinephrine by the adrenal medulla? a) Adrenergic a receptor. b) Adrenergic ẞ receptor. c) Cholinergic nicotinic receptor. d) Cholinergic muscarinic receptor. 86. Regarding the nicotinic cholinergic receptors, all of the following is true, EXCEPT: a) They are blocked by atropine. b) They are present at the motor end plate. c) They are found in the suprarenal medulla. d) Are members of ligand-gated ion channels. 87. Muscarinic receptors bind: a) Epinephrine. b) Norepinephrine. c) Acetylcholine. d) Cholinesterase. 88. The receptors facing the postganglionic parasympathetic fibers are: a) Nicotinic. b) Muscarinic. c) Alpha adrenergic. d) Beta adrenergic. 89. Which of the following responses is mediated by parasympathetic muscarinic receptors? a) Erection. b) Ejaculation. c) Dilation of bronchiolar smooth muscle. d) Contraction of gastrointestinal (GI) sphincters. 90. The eccrine sweat glands are innervated by: a) - Adrenergic preganglionic sympathetic fibers. b) Adrenergic postganglionic sympathetic fibers. c) Cholinergic postganglionic sympathetic fibers. d) Cholinergic postganglionic parasympathetic fibers. 91. Which of the following is used in treatment of myasthenia gravis: a) Curare. b) Eserine. c) Atropine. d) Prostigmine. 92. Administration of physostigmine, a drug that inhibit acetyl choline esterase, would be expected to produce all the following, EXCEPT: a) Slowing of the heart. b) Inhibition of micturition. c) An increase of gastric secretion. d) An increase of adrenaline secretion from adrenal medulla. 93. Administration of physostigmine, a drug that inhibits acetylcholine esterase, would be expected to produce all the following EXCEPT: a) Cause hypotension & bradycardia. b) Produce lacrimation & bronchodilatation. c) Increase the secretion of gastric & pancreatic juices. d) Increase the rate of epinephrine secretion from adrenal medulla. 94. Administration of prostigmine, a drug that inhibits acetylcholine esterase, would be expected to: a) Cause retention of urine. b) Inhibit salivary secretion. c) Produce dilatation of pupil. d) Increase the secretion of gastric juice. 95. About prostigmine (neostigmine), all are true EXCEPT: a) Inhibits cholinesterase enzyme. b) Is an irreversible anticholinesterase. c) Acts specifically at motor end plate. d) Is used in treatment of myasthenia gravis. 96. The antidote of eserine is: a) Atropine. b) Ergotoxine. c) Amphetamine. d) Noradrelanine. 97. Which is the most important drug in the treatment of organophosphate poisoning (Malathion poisoning): a) Atropine. b) Adrenaline. c) Pilocarpine. d) Prostigmine. 98. Atropine injection causes, all the following EXCEPT: a) Pupillodilatation. b) Increased heart rate. c) Diminished salivary secretion. d) Relaxation of skeletal muscles. 99. Atropine injection causes, all the following EXCEPT: a) Pupillo-dilatation. b) Difficult micturition. c) Constriction of the bronchi. d) An increase in the heart rate. 100. Atropine blocks the action of ACh at the following sites EXCEPT: a) Heart. b) Sweat glands. c) Adrenal medulla. d) Constrictor pupillae muscle. 101. Atropine blocks the action of ACh on receptors located in the following areas, EXCEPT: a) Iris. b) Heart. c) Motor end plate. d) The gastric glands secreting HCl. 102. Administration of atropine, a drug that blocks muscarinic receptors, would be expected to produce: a) Constriction of the pupil. b) Slowing of the heart rate. c) Decrease of gastric secretion. d) An increase contractility of ventricular muscle. 103. Atropine causes dry mouth by inhibiting which of the following receptots? a) a receptor. b) ẞ receptor. c) Nicotinic receptor. d) Muscarinic receptor. 104. Atropine causes: a) Bradycardia during rest. b) Dryness of mouth & skin. c) Contraction of ciliary muscle. d) Bronchodilatation & increases bronchial secretion. 105. Atropine: a) Stimulates sweat secretion. b) Stimulates bronchial secretion. c) Decreases gastric acid secretion. d) Increases the tone & motility of GIT. 106. Atropine is given before surgical operations to: a) Decrease heart rate. b) Relax skeletal muscle. c) Prevent bronchial secretion. d) Induce bronchoconstriction. 107. Curare: a) Causes relaxation of smooth muscles. b) Blocks the neuromuscular transmission. c) Competes with acetyl choline at autonomic ganglia. d) Prevents the release of acetyl choline at motor end plate. 108. Which autonomic receptor is blocked by hexamethonium at the ganglia, but not at the motor end plate? a) Adrenergic ẞı receptors. b) Adrenergic ẞ2 receptors. c) Cholinergic nicotinic receptors. d) Cholinergic muscarinic receptors. 109. Acetyl choline: a) Release is blocked by curare at motor end plate. b) Synthesis is catalyzed by cholinesterase enzyme. c) Action at motor end plate is blocked by atropine. d) Is secreted by some sympathetic postganglionic nerve fibers. 110. Which of the following is NOT synthesized in postganglionic sympathetic neurons: a) Dopamine. b) Epinephrine. c) Acetylcholine. d) Norepinephrine. 111. Epinephrine is secreted by: a) The adrenal medulla. b) Sympathetic preganglionic fibers. c) Sympathetic postganglionic fibers. d) Parasympathetic postganglionic fibers. 112. Concerning Epinephrine, all the following is true EXCEPT: a) Helps in treatment of bronchial asthma. b) Is less potent than norepinephrine as a pressor (VC) agent. c) Is synthesized in adrenal medulla by methylation of norepinephrine. d) Is the chemical transmitter of adrenergic postganglionic sympathetic fibers. 113. Epinephrine is: a) Synthesized in the adrenal medulla by methylation of norepinephrine. b) Hydrolyzed by the cholinestrase enzyme. c) The chemical transmitter of most symp. postganglionic nerve fibers. d) More powerful as a pressor agent than norepinephrine. 114. Noradrenaline: a) Is a potent vasodilator. b) Increases intestinal motility. c) Is the neurotransmitter at the alpha-adrenergic receptors. d) Is released by both pre- & postganglionic sympathetic nerve endings. 115. Concerning norepinephrine, all is true EXCEPT: a) Secreted under stressful conditions. b) Contributes to 20% of the suprarenal medulla secretion. c) Is released by both pre- & postganglionic sympathetic nerve endings. d) It is the chemical transmitter at most sympathetic postganglionic fibers. 116. Removal of norepinephrine at postganglionic sympathetic fibers occurs by: a) A demethylation reaction. b) Transformation into epinephrine. c) The action of transaminase enzyme. d) Reuptake back into the terminal sympathetic nerve endings. 117. Which of these fibers release norepinephrine? a) Preganglionic parasympathetic fibers. b) Postganglionic parasympathetic fibers. c) - Postganglionic sympathetic fibers in the heart. d) Postganglionic sympathetic fibers in sweat glands. 118. Epinephrine produces all the following effects EXCEPT: a) Coronary VD. b) Cutaneous VC. c) Glycogenolysis. d) Bronchoconstriction. 119. Which of these results from stimulation of alpha-adrenergic receptors? a) Increased heart rate. b) Sweat gland secretion. c) Dilation of bronchioles. d) Constriction of cutaneous blood vessels. 120. Stimulation of a adrenoceptors produces all the following EXCEPT: a) Ejaculation of semen. b) Contraction of dilator pupillae muscle. c) - Constriction of cutaneous blood vessels. d) Dilatation of skeletal muscle blood vessels. 121. The a-adrenoceptors mediate all the following effects EXCEPT: a) Pupil dilatation. b) Vasoconstriction. c) Spleen contraction. d) Increased cardiac activity. 122. The a-adrenergic receptors: a) Are blocked by propranolol. b) Are not stimulated by epinephrine. c) When stimulated, they accelerate the heart. d) When stimulated, they reduce the gastrointestinal (GI) motility. 123. Giving alpha blocking drugs; a) Impairs ejaculation. b) Increases heart rate. c) Promotes bronchodilatation. d) Increases secretion of sweat glands. 124. Which adrenergic receptor produces its stimulatory effect through increasing intracellular Cat: a) a receptors. b) a2 receptors. c) ẞı receptors. d) ẞ2 receptors. 125. A fall in cyclic AMP within the target cell occurs when norepinephrine binds to which of adrenergic receptors? a) a receptors. b) a2 receptors. c) ẞı receptors. d) ẞ2 receptors. 126. Alpha2 adrenergic receptors on presynaptic axon terminals, when stimulated, cause: a) Increased release of epinephrine. b) Increased release of norepinephrine. c) Decreased release of epinephrine. d) Decreased release of norepinephrine. 127. A drug that serves as an agonist for a2 receptors can be used to: a) Increase the heart rate. b) Decrease the heart rate. c) Constrict the bronchioles. d) Constrict the blood vessels. 128. Which autonomic receptor mediates an increase in the heart rate? a) Adrenergic ẞı receptors. b) Adrenergic ẞ2 receptors. c) Cholinergic nicotinic receptors. d) Cholinergic muscarinic receptors. 129. Concerning adrenoceptors, all the following is true EXCEPT: a) Stimulation of alpha adrenoceptors causes bronchodilatation. b) Stimulation of ẞ, receptors causes renin secretion & lipolysis. c) Activation of ẞ1 & B2 adrenoceptors result in activation of adenyl cyclase. d) Stimulation of ẞ, adrenoceptors increases the force & rate of cardiac contraction. 130. Sympathetic postganglionic neurons innervating the heart release the neurotransmitter that binds to --------receptors. a) Acetylcholine, muscarinic (M2). b) Norepinephrine, adrenergic (βι). c) Norepinephrine, adrenergic (B2). d) Norepinephrine, muscarinic (M2). 13