Select (Encircle) the one lettered answer that is best for each question. Q1) The structure of the SA node and the AV node represents with which one of the following structures: abcd- A collection of nerve cell bodies. A collection of axon terminals. A collection of modified cardiac cells with gap junctions. A collection of lymphoid mass with electrolytes. Q2) Out of 60% of the body weight, the % of water constitutes intracellular fluid: abcd- 20 40 60 70 Q3) In which of the following conditions, the heart rate becomes high: abcd- Emotions. Physical exercise. Fever. All of the above are correct. Q4) Which one of the following is the outer layer of the heart: abcd- Epicardium. Pericardium. Endocardium. Protocardium. Q5) Which of the following factors increases the length of the cardiac muscle fiber: abcd- When the person assume a standing posture. When there is an increased total blood volume. When there is an increased intra-pericardial pressure. When there is a decreased ventricular volume. Q6) Myocardial contractility is best correlated with intracellular concentration of: a- Na+ b- K+ c- Ca+2 d- ClQ7) Which one of the following structures is the only conducting pathway for an impulse between the atria and ventricles: abcd- Cardiac muscle fibers. Atrioventricular node. Purkinji fibers. Atrioventricular septum. Q8) Which one of the following is the reason for the first heart sound: abcd- Vibrations caused by the closure of aortic valve. Vibrations caused by the closure of bicuspid and tricuspid valves. Vibrations caused by the closure of the pulmonary valve. Vibrations caused by the closure of aortic and pulmonary valves. Q9) Which one of the following sections of the blood vessels occupies the largest cross-sectional are in the human body: abcd- Capillary. Arteriole. Artery. Aorta. Q10) Which one of the following facts is true about the velocity of blood flow: abcd- It is higher in capillaries than arterioles. It is higher in veins than arteries. It is higher in veins than venules. It falls to zero in the descending aorta during diastole. Q11) Which one of the following increases with the increase of arteriolar radius: abcd- Capillary blood flow. Systolic blood pressure. Diastolic blood pressure. Viscosity of blood. Q12) The intrinsic rate of discharge of the S.A node is: abcd- 60 beats/minute. 80 beats/minute. 100 beats/minute. 120 beats/minute. Q13) Q wave of the ECG recording represents: abcd- Depolarization of the apex of the heart. Depolarization of the interventricular septum. Depolarization of the base of the left ventricle. Depolarization of the base of the right ventricle. Q14) Blood pressure for a healthy 20 year old male at rest is: abcd- 100 mmHg at systole and 50 mmHg at diastole. 120 mmHg at systole and 70 mmHg at diastole. 140 mmHg at systole and 90 mmHg at diastole. 150 mmHg at systole and 90 mmHg at diastole. Q15) The terms vasoconstriction and vasodilation are used in respect with which one of the following: abcd- Large Arteries. Arterioles Venules. Capillaries. Q16) Which one of the following is greatly reduced at a heart rate above 200 beats/minute : abcd- The atrial filling period. The atrial relaxation period. The ventricular systole period. The ventricular diastole period. Q17) The short-term mechanism for regulation of arterial blood pressure is achieved by the: abcd- Carotid chemoreceptors. Carotid baroreceptors. Aortic chemoreceptors. Renin-angiotensin system. Q18) The third heart sound is caused by: abcd- Closure of the atrioventricular valves. Closure of the aortic valve. Blood turbulence during ventricular filling. Blood turbulence during atrial systole. Q19) The normal venous return to the heart during rest is: abcd- 2 liters/minutes. 2 liters/minutes. 4 liters/minutes. 5 liters/minutes. Q20) Which one of the following increases when viscosity of blood increases: abcd- Central venous pressure. Capillary blood flow. Radius of arterioles. Mean arterial blood pressure. Q21) Which one of the following does not help in inspiration: abcd- Increased intrathoracic volume. Decreased intrapleural pressure. Decreased pressure in the airway. Lungs recoil activity. Q22) Which one of the following produces surfactant: abcd- Type I alveolar cell. Type II alveolar cell. Alveolar macrophage. Pulmonary capillary endothelial cell. Q23) External respiration: abcd- Is a process of ATP production. Is known as cellular respiration. Involves gas exchange between pulmonary capillary blood and tissues. All of the above are correct. Q24) The normal inspiratory reserve volume in adult male is: abcd- 1000 ml of air. 1200 ml of air. 2200 ml of air. 3000 ml of air. 25) During quiet respiration the volume of air remains in the lungs at the end of expiration: abcd- Zero. 0.5 liter. 1.2 liter. 2.2 liter. 26) The main expiratory muscles during heavy ventilation is: abcd- Diaphragm. Sternocleidomastoid muscles. Abdominal muscles. Scalene muscles. 27) The ciliated epithelium in the airway is present up to which one of the following structures: abcd- Alveolar ducts. Alveolar sacs. Alveoli. Respiratory bronchioles. 28) The normal respiratory rate under resting condition is: abcd- 10 breath/minute. 16 breath/minute. 26 breath/minute. 36 breath/minute. 29) The main inspiratory muscle is the: abcd- External intercostal muscle. Scalene muscle. Pectoralis minor muscle. Diaphragm. 30) Which one of the following structures is not included in the respiratory zone: abcd- Alveoli. Alveolar duct. Terminal bronchioles. Respiratory bronchioles.