1 四川大学期末考试试题 I. Explain the following terms (24 points, 3 for each) 1. action potential ： A rapid, reversible and conductible fluctuation of the membrane potential of cell when stimulated.2. gastrointestinal hormones: Biologically active polypeptides secreted by the endocrine cells in gastrointestinal tract which influence the motility and secretion of gastrointestinal tract. 3. cardiac cycle: The period from the beginning of heart contraction to the beginning of next is called a cardiac cycle (consisting of a period of contraction called systole followed by a period of relaxation called diastole). 4. visual acuity: The smallest image on the retina distinguished by the human eyes. 5. thermal equivalent of food: The amount of energy liberated by oxidation or combustion of 1g of food. 6. pulmonary ventilation: The process that O2 and CO2 move into and out of the lung by the respiratory tract. 7. blood types: Types of specific antigens expressed on blood cells 8. reflex: The regular response made by the body to stimulation under control of central nervous system. II. Fill in the blanks (22 points, 1 for each) 1. In the automatic control system, the controlled part send (feedback signal) to controlling system to adjust its previous activities. 2. For skeletal muscle cell, the ion with the highest permeability at rest which makes greatest contribution to the resting potential is（ K+） . 3. In transmission of excitation at neuromuscular junction, the Ca 2+ uptake of prejunctinal terminal causes （ACh release）. 4. The digestion of proteins begins at （stomach）. 5. One of the properties of contraction of the myocardium is that the atria or ventricle contracts as a functional（syncytium）. 6. The ratio of the stroke volume to the ventricular end-diastolic volume is called （ejection fraction ）. 2 7. The norepinephrine in the circulating blood mainly comes from （adrenal medulla） and （adrenergic nervous terminals）. 8. The commmonly used method of measuring energy metabolism is （indirect calorimetry）. 9. Two or more substances connect with a transporter and are transported together across the membrane at the same direction, this transport is called （symport）. 10. Angiotensin will increase the secretion of （aldosterone） of the zona cells in the andrenal cortex. 11. The intensity of stimulus can be distinguished by （the frequence） of action potential generated on the afferent neuron. 12. According to the statement about the optical mechanism of refractive system, the focus point is located on the （retina）. 13. Respiratory chemoreceptors in the medulla are mainly responsive to alteration in arterial （PCO2）. 14. The vast majority of carbon dioxide is carried by （HCO3-） in blood. 15. The volume which has to be ventilated but does not participate in gas exchange is called （dead space）. 16. Blood coagulation refers to the process of conversion of fibrinogen to （fibrin）. 17. The summation of membrane potential caused by successive discharges from a single presynaptic terminal is called （temporal summation）. 18. The sense organ of the stretch reflex is the （muscle spindle）. 19. Functions of the specific projection system include （production of specific sensation） and （triggering of efferent impulses）. 20. The phenomena that a single instantaneous input signal cause a sustained signal output usually occurred in （oscillatory） circuit. III. Fill in the blanks with the best choice (34 points, 1 for each) 3 1. Transmission of excitation at neuromuscular junction is mediated by ( C ). A. epinephrine B. norepinephrine C. acetylcholine D. somatostatin 2. Which component is shared by skeletal muscle and cardiac muscle for exitation-contraction coupling ? ( A ) A. intracellular Ca2+ B. extracellular Ca2+ C. intracellular and extracellular Ca2+ D.Ca2+ in blood 3. Which of the following statements about G protein is correct? ( D ) A. can bind to ligand directly B. there are two subunits C. only binds to GTP D. active G protein can activate the effector molecules, enzymes or channels 4. The principal paracrine secretion involved in the negative feedback regulation of gastric acid secretion is ( B ). A. acetylcholine B. somatostatin C. histamine D. gastrin 5. Slow waves in small intestinal smooth muscle cells are ( D ). A. phasic contraction B. action potential C. tonic contraction D. fluctuation of membrane potential on RP 6. The baroreceptor reflex is ( D ) A. not sensitive at the level of around the mean blood pressure B. not sensitive to a rapid change in the blood pressure C. not sensitive to pulsative change in the blood pressure D. no doubt always important for the regulation of the blood pressure 7. The work performed by the left ventricle is substantially greater than that performed by the right ventricle because in the left ventricle ( D ). A. the contraction is slower B. the stroke volume is greater C. the preload is greater D. the afterload is