Physiology Lecture 12 MCQ & SEQ PDF

Physiology Questions LECTURE (12) – MCQ & SEQ DR. El-Sawy 1  Physiology Question...

Physiology Questions LECTURE (12) – MCQ & SEQ DR. El-Sawy 1  Physiology Questions 1) Sympathetic blockers can be used in the treatment of the following diseases except: a) hypertension. C b) Angina pectoris. c) Peptic ulcer. d) All of the above 2) All the following statements are true except: a) Vagotomy may cause the heart rate to increase. b) Arteriolar V.C. present at rest may be due to a basal secretion of C catcholamines from the adrenal medulla. c) Noradrenaline is not secreted by the adrenal medulla. d) Adrenaline is secreted by the adrenal medulla. 3) About the chemical transmission in the symp. N.S: a) Noradrenaline is released by both the. pregang. & postgang. Symp. Nerve fibers. b) Noradrenaline contributes to 80% of the secretion of the suprarenal C medullae c) The alpha-adrenergic stimulators cause contraction of the plain muscles in the seminal vesicles & vas deferens. d) Noradrenaline is released by. Pregang postgang. Symp. Nerve fibers. 4) Drugs which block beta adrenoceptors is likely to Cause: a) Relaxation of sphincters in the alimentary tract. b) Dilatation of the bronchi. C c) A decrease in the force of myocardial contraction in someone with heart failure. d) None of the above DR. El-Sawy 2  Physiology Questions 5) Drugs that block alpha adrenergic receptors is likely to cause: a) A reduction in sweat production. b) Slowing of the heart. C c) Failure of mydriasis in emotions. d) All of the above 6) A drug which blocks beta adrenergic receptors causes: a) Dilatation of the bronchial muscle. b) Relaxation of the sphincters in the alimentary canal. C c) Inhibition of cardiac properties. d) All of the above 7) The alpha-adrenergic receptors: a) Are not stimulated by epinephrine. b) When stimulated, they reduce the gastrointestinal (GI) motility. B c) Are blocked by propranolol. d) Are 5 types 8) A drug that blocks the beta-adrenergic receptors in likely to cause: a) Relaxation of the sphincters of the GIT. b) An increase in the cardiac properties C c) Bronchoconstriction. d) Contraction of GIT walls 9) Epinephrine produces all the following effects except: a. Bronchoconstriction., b. Coronary V.D. A c. Glycogenolysis. d. inhibition of pancreatic scretion DR. El-Sawy 3  Physiology Questions 10) Stimulation of the alpha-adrenergic receptors produces: a) Increase gastrointestinal motility. b) Bronchodilatation. C c) Contraction of the spleen capsule. d) All of the above 11) The alpha-adrenergic receptors mediate all the following effects except: a) Vasoconstriction. C b) Spleen contraction. c) increased cardiac activity. d) All of the above 12) An increased secretion of epinephrine causes a) Increased myocardial contraction & V.D. b) decreased myocardial contraction & V.D. A c) decreased myocardial contraction & V.C. d) All of the above 13) A physiological action of epinephrine produced by contact with the beta-adrenergic receptors is a) Dilatation of the pupil. C b) Intestinal contraction. c) Increased strength of myocardial contraction. d) All of the above 14) Blockage of alpha adreno-receptors is likely to cause: a) A reduction in sweat production. b) Constriction of the bronchi. C c) A reduction in the arterial blood pressure due to arterial V.D. d) All of the above DR. El-Sawy 4  Physiology Questions 15) Alpha adrenoreceptors: a) Are present in the myofilaments of skeletal muscle cells. b) Can be distinguished from beta receptor using the electron microscope. C c) Are stimulated by both adrenaline and noradrenaline. d) Are main receptors in the heart 16) Epinephrine is: a) Synthesized in the adrenal medulla by methylation of norepinephrine. b) The chemical transmitter of most sympathetic postganglionic nerve A fibers. c) More powerful as a pressor agent than norepinephrine. d) All of the above 17) The alpha-adrenergic receptors: a) Are not stimulated by epinephrine. b) When stimulated, they reduce the gastrointestinal motility. B c) Are blocked by propranolol. d) All of the above 18) A drug which blocks the beta-adrenergic receptors causes: a) Dilatation of the bronchial muscle. b) Relaxation of the sphincters in the alimentary canal. C c) Fall in the cardiac output. d) All of the above 19) Noradrenaline (norepinephrine) : a) Is liberated by symp. preganglionic fibers that supply adrenal medulla B b) Is released by the symp. postganglionic neurons that supply the heart. c) Acts only on the alpha-adrenergic receptors. d) Acts only on the beta-adrenergic receptors. DR. El-Sawy 5  Physiology Questions 20) About norepinephrine (noradrenaline): a) It release is inhibited by ephedrine and stimulated by guanethidine. b) chemical transmitter of parasympathetic postganglionic nerve fibres. C c) It is inactivated by MAO (monoamine oxidase enzyme). d) All of the above 21) alpha adrenergic receptors mediate all effects except: a) Vasoconstriction. b) Spleen contraction. C c) Increased cardiac activity. d) All of the above 22) drug that blocks the alpha-adrenergic receptors is likely to cause: a) A reduction in sweat production. b) A fall in the arterial blood pressure due to slowing of the heart. C c) Failure of mydriasis in emotions. d) None of the above 23) A drug that blocks the alpha-adrenergic receptors is likely to cause: a. A reduction in sweat production. b. A fall in the arterial blood pressure due to slowing of the heart. C c. Failure of mydriasis in emotions. d. None of the above 24) Excessive sweating in a certain region can be relieved by: a) Drugs that interfere with transmission at adrenergic nerve fibers. b) Drugs that interfere with transmission at cholinergic nerve fibers. B c) Division of the parasympathetic neurons that supply the affected region. d) All of the above DR. El-Sawy 6  Physiology Questions 25) physiological action of epinephrine produced by contact with the beta-adrenergic receptors is: a) V.C. in skeletal muscles. C b) Dilatation of the pupil. c) Increased strength of myocardial contraction d) None of the above 26) Blockade of alpha adrenoceptors is likely to cause a reduction in: a) Sweat production. b) Bronchus diameter. C c) Total peripheral resistance. d) None of the above 27) Which autonomic receptor mediates an increase in heart rate? a. Adrenergic α1receptors b. Adrenergic β 1 receptor B c. Adrenergic β 2 receptors d. Muscarinic receptors 28) Which adrenergic receptor produces its stimulatory effects by the formation of inositol1,4,5-triphosphate (IP3) and an increase in intracellular [Ca2+]? a) α1 Receptors A b) α 2 Receptors c) β1 Receptors d) Β3 Receptors DR. El-Sawy 7  Physiology Questions 29) Which autonomic receptor mediates secretion of epinephrine by the adrenal medulla? a) Adrenergic β1 receptors C b) Adrenergic α 1 receptor c) Cholinergic nicotinic receptors d) Adrenergic α 2 receptors 30) Which of the following autonomic drugs acts by stimulating adenylate cyclase? a) Atropine C b) Clonidine c) Norepinephrine d) Muscarine 31) Activation of which of the following receptors increases total peripheral resistance (TPR)? a. α 1 Receptor A b. β 1 Receptor c. β 2 Receptor d. Muscarinic receptors 32) Removal of norepinephrine at postganglionic sympathetic fibers occurs by: a) Reuptake back into the terminal sympathetic nerve endings b) Transformation into epinephrine. A c) The action cholinestrase enzyme. d) A demethylation action. e) Transformation into choline. DR. El-Sawy 8  Physiology Questions 33) Noradrenaline a) Increases intestinal motility. b) Is the neurotransmitter in the alpha-adrenergic receptors B c) Is released by both pre- & postganglionic sympathetic nerve endings. d) is a potent vasodilator e) Hydrolyzed by cholinestrase enzyme. 34) Alpha 1 adrenergic receptors : a) Present in the myofilaments of skeletal muscle cells b) Can be distinguished from beta receptors using the microscope C c) Stimulated by both adrenaline and noradrenaline d) Mediate acceleration of the heart e) Help neuromuscular transmission 35) Activation of alpha-1 adrenergic receptors would : a) Increase rennin secretion from kidney b) Constrict pulmonary arterioles. B c) Constrict bronchioles d) Dilate cerebral arterioles 36) Blockade of alpha-1 adrenergic receptor is likely to cause: a) Contraction of bladder and GIT sphincters. b) Constriction of the bronchi D c) Dilatation of pupil. d) A reduction in the arterial blood pressure due to arterial vasodilatation DR. El-Sawy 9  Physiology Questions 37) Stimulation of alpha-1 adrenergic receptors a) Dilates skeletal muscle blood vessels. b) Ejaculate semen B c) Helps neuromuscular transmission d) Helps transmission in autonomic ganglia 38) Stimulation of alpha-1 adrenergic receptors a) Contracts dilator pupillae muscle.. b) Dilates skeletal muscle blood vessels. A c) Helps neuromuscular transmission d) Helps transmission in autonomic ganglia DR. El-Sawy 10  Physiology Questions Sites of release of Catecholamines: 1. All sympathetic postganglionic fibers except : Sweat glands. Skeletal muscle Blood vessel. 2. Adrenal Medulla: Adrenaline (80%) Noradrenaline (40%) 3. Some Synapses in the CNS. Synthesis of Catecholamines:  In liver: Hydroxylation Phenyl-alanine Tyrosine  In axoplasm of adrenergic nerve fibers: Hydroxylation Tyrosine DOPA ( Di-hydroxy phenyl-alanine) Decarboxylation DOPA Dopamine  Dopamine is transported into vesicles into nerve ending : Dopamine + OH Noradrenaline  In SRM and CNS neurons: This reaction goes one step to form adrenaline. + CH3 Noradrenaline Adrenaline DR. El-Sawy 11  Physiology Questions Mechanism of action of Catecholamines :  Catecholamines binds to receptors on postsynaptic membrane it either : 1. ↑ permeability to Na and Ca → Na and Ca influx → Depolarization (stimulation ) 2. ↑ permeability to K and Cl → K efflux and Cl influx → Hyper-polarization ( inhibition) 3. Stimulation of adenyl-cyclase : → Conversion of ATP into C-AMP (initiate many intracellular activities) Explain Removal of catecholamines : Neuronal uptake Extra neuronal uptake Excretion in urine Accounts for removal Account for removal of 15% Very small of 85 % Destroyed by C.O.M.T. amount Either stored or destroyed by M. A.O Compare ( ) Mono-amino-oxidase & Catecholamine o- methyle transferase. MOA COMT Neuronal uptake. Extra -neuronal uptake. Produce oxidation Produce methylation Remove 85%. Remove 15%. Present in mitochondria of Present in all tissues especially adrenergic fibers , liver & kidney kidney & brain DR. El-Sawy 12  Physiology Questions Compare ( ) alpha 1 and alpha 2 Adrenergic receptors: Alpha Alpha  Postsynaptic membrane on  Pre-synaptic sympathetic effector organ nerve ending & ganglion Site cells (auto receptors)  Post-synaptic membrane of effector organ  Activation of protein G→  Activation of protein G a. ↑Intracellular IP3 → inhibit Adenyl cyclaze MOA b. ↑intracellular Ca enzyme  Ca & IP3 act as second → ↓ C-AMP messenger  Mainly Excitatory :  Mainly inhibitory : 1. V.C of blood vessels 1. Pre-synaptic : 2. Contraction of pilo-erector ms. -ve feedback 3. Contraction of splenic capsule. inhibition of more 4. Contraction of seminal vesicle & Nor-adrenaline ejaculatory duct. release Action 5. Contraction of bladder and GIT 2. Post-synaptic : sphincters V.C of some vessels 6. Adrenergic sweating on palm. CNS inhibition.  May be inhibitory : ↓ lipolysis 1. Intestinal relaxation ↓ Insulin secretion. 2. Inhibition of insulin secretion Peripheral platelet aggregation Agonist Adrenaline & Nor-Adrenaline Sensitivity Equal to both Adrenaline & Nor-Adrenaline DR. El-Sawy 13  Physiology Questions Compare ( ) beta 1 and beta 2 Adrenergic receptors: Beta Beta  Post-synaptic membrane  Post-synaptic membrane in in effector organs as : effector organs as smooth ms of: 1) Heart. 1) Skeletal ms blood vessels Site 2) Intestine. 2) Bronchial wall 3) Kidney. 3) Bladder wall 4) Fat cells. 4) GIT wall  Activation of protein G MOA → Stimulation of Adenyl cyclaze enzyme → ↑ C-AMP  Mainly Excitatory :  Mainly inhibitory : 1. ↑ all cardiac 1. Smooth muscle relaxation properties Intestinal, bladder 2. ↑ rennin secretion relaxation 3. ↑ lipolysis. Vaso-dilatation 4. ↓ platelet aggregation Broncho-dilation Action 2. Stimulation of liver and ms glycogenolysis. 3. Stimulation of insulin secretion 4. Increased blood fibrinogen level. Agonist Adrenaline & NA Adrenaline Equal to both Adrenaline & Sensitivity More sensitive to Adrenaline Nor-Adrenaline DR. El-Sawy 14