1. Consider a sample of normal human blood that contains approximately 60% plasma. This blood would… a. have a hematocrit of about 40. b. would contain about 40% erythrocytes by volume c. would contain about 40% platelets by volume. d. Would contain about 40% leukocytes by volume e. a and b $ 2. In the systemic circulation the distribution of total blood volume is such that… a. The Capillaries have the highest blood volume because, even though they are very small in diameter and relatively short in length, they are very numerous. b. The Arteries have the highest blood volume because they are very elastic. c. The Veins have the highest blood volume because they are very compliant over a normal range of transmural pressures. $ d. All of the above e. None of the above 3. Application of a drug which increased K+ (potassium) permeability during phase 4 of the Sino-Atrial nodal action potential would be expected to… a. increase the slope of the pacemaker potential. b. cause an increase in heart rate. c. cause a positive inotropic response in SA nodal cells. d. a and b e. none of the above $ 4. Considering all the potentially self-excitatory tissue in the heart, the Sino-Atrial node is the normal cardiac pacemaker because… a. phase zero of the SA nodal action potential is caused by rapid Na+ (sodium) influx. b. increased Ca++ (calcium) permeability causes repolarization of SA nodal cells. c. the SA node has the highest natural rate of spontaneous action potential generation of all potentially self-excitatory cardiac tissues. $ d. the SA node is the only potential cardiac pacemaker innervated by motor nerves. e. none of the above 5. Cardiac muscle differs from skeletal muscle in that…a. there is no release of Ca++ (calcium) from the SR (Sarcoplasmic Reticulum) during excitation-contraction coupling in cardiac myofibers. b. cardiac myofibers are innervated by autonomic nerve fibers. c. the force of cardiac muscle contraction can not be summated as a result of an increase of frequency of stimulation. d. all of the above e. b and c $ 6. Consider the following values for a systemic capillary: Pcap = 30 mmHg; Pint = 2 mmHg; COPcap = 20 mmHg; COPint = 2 mmHg; permeability is normal and body temperature = 37q C. One would expect… a. net capillary filtration $ b. net capillary reabsorption 7. During the normal cardiac cycle the period of time that elapses from the closure of the AV (Atrio-Ventricular) valves until the closure of the semilunar valves … a. Is characterized by ventricular filling. b. Is the period of ventricular Systole. c. Is the period of isovolumetric ventricular relaxation. d. Includes the ejection of the stroke volume. e. b and d $ 8. Consider the normal effects of exercise on a whole skeletal muscle. As a result of a modest increase in frequency and force of contraction, one would expect… a. the intracellular PCO2 in the muscle’s myofibers to decrease from the level it had when the muscle was at rest. b. total vascular resistance in the muscle to increase as a result of increased sympathetic nervous system (SNS) activity. c. blood flow in the muscle to increase from its resting level as a result of metabolic vasodilation. $ d. all of the above e. a and c 9. Blood will not clot in the absence of… a. Thrombin b. Fibrinogen c. sunlight d. a and b $ e. All of the above10. In compensation for a significant fall in mean systemic arterial blood pressure, such as could be caused by hemorrhage, one would expect… a. An increase in sympathetic nervous system (SNS) activity. b. Positive inotropism in the myocardium. c. decreased renal and intestinal vascular resistance. d. all of the above e. a and b $ 11. Human Red Blood Cells (Erythrocytes)… a. contain hemoglobin. b. are produced in bone marrow. c. are the most abundant cellular type in blood. d. all of the above $ e. a and c 12. Systemic Capillaries… a. provide significant resistance to blood flow because of the high density of sympathetic (SNS) innervation of the vascular smooth muscle present within the capillary wall. b. Are more permeable to plasma proteins than blood gases. c. Are relatively impermeable to H2O. d. All of the above e. None of the above $ 13. The major physiological means of decreasing heat loss in response to cold environmental temperature is? a. skin vasoconstriction $ b. muscle vasoconstriction c. shivering d. increasing metabolic activity, i.e. exercising. e. a and c 14. Which of the following would result in increased mean systemic arterial blood pressure in an otherwise normal resting individual … a. increased adrenal release of epinephrine. $ b. An increase in the frequency of firing of carotid sinus and aortic arch barorecptors. c. bradycardia d. all of the above e. a and b15. Consider a blood vessel in which the upstream blood pressure is 30 mmHg, the downstream blood pressure is 20 mmHg, and the blood flow rate is 5ml/min. The vascular resistance in this vessel would be? a. 0.2 mmHg/ml/min b. 2.0 mmHg/ml/min $ c. 20.0 mmHg/ml/min d. 25 mmHg e. none of the above 16. The primary hormone which stimulates Red Blood Cell production is produced in the… a. bone marrow b. adrenal gland c. kidney $ d. posterior pituitary gland e. none of the above 17. Consider an individual who is spontaneously breathing a gas mixture containing 10% Oxygen (O2) with the balance Nitrogen. One would expect… a. The O2 saturation of Hemoglobin to fall to less than 10% of its normal value. b. O2 content of arterial blood to increase. c. increased ventilatory rate due to peripheral chemoreceptor stimulation. $ d. none of the above e. a and c 18. Central Chemoreceptors … a. Are located in the right atrium of the heart. b. Are Important in the regulation of arterial PCO2. c. Respond to changes in their intracellular H+ concentration. d. All of the above e. b and c $ 19. Consider the mammalian heart… a. The atria are thin-walled, contractile chambers which are important in setting ventricular end diastolic volume. $ b. Cardiac electrical activity normally passes directly from atrial myocardial cells to ventricular myocardial cells during activation of the heart.c. Both ventricles pump arterial blood. d. Cardiac metabolic activity is unaffected by the Autonomic Nervous System (ANS). e. none of the above 20. As a result of