ID: A 56. The chemoreceptors in the carotid bodies are particularly sensitive to
ID: 3505992 • Letter: I
Question
ID: A 56. The chemoreceptors in the carotid bodies are particularly sensitive tor a. b. hypoxia. c. a decrease in blood pHL. d. an increase in the hydrogen ion concentration of the blood 57. Which of the following is true of the conduction system of the a. It is made of cardiac muscle. b. It is made of nervous tissue. It continues its contractile roll even while conducting an impulse d. c. Both A and C are true of the conduction s system of the heart 58. Which part of the conduction system of the heart is referred to as the pacemaker? a. Purkinje fibers b. Sinoatrial node c. Atrioventricular node d. Atrioventricular bundles 59. Which of the following is not a means by which venous blood is returned to the heart? a. The semilunar valves in the vein b. Respiration, which reduces pressure in the thorax and increases pressure in the abdomen c. The contraction of skeletal muscles pushing blood through the veins d. All the above are means by which venous blood returns to the heart. Which of the following factors would cause fluid to leave the blood vessel at the arterial end of the capillary? a. High hydrostatic pressure of the blood b. High hydrostatic pressure of the interstitial fluid c. High colloid pressure of the plasma proteins d. All of the above 60. Which of the following factors venous end of the capillary? a. High hydrostatic pressure of the blood b. High colloid pressure of the plasma proteins c. Hydrostatic pressure of the interstitial fluid d. Both B and C 61. 62. The period bewenthe closure of the semilunar valve and the opening of the atrioventricular valves is called: a. atrial systole. b. isovolumetric ventricular contraction. c. isovolumetric ventricular relaxation. d. passive ventricular filling.Explanation / Answer
56) a) Hypercapnia – It is known as hypercarbia and carbon dioxide retention. In this condition, there is abnormal elevation in the level of the carbon dioxide in the blood. It is a serious condition and the carotid bodies in chemoreceptors are sensitive to the same.
57) d) Both A and C are true of the conduction system of the heart
The cardiac conduction system is basically a specialized system made of cardiac muscle cells and it helps in sending the signals to the heart muscle. This helps in contraction of the heart muscle. It conducts the impulse and while doing so it continues its roll
58) b) Sinoatrial node
The SA node is the natural pacemaker of the heart. The electrical impulses from the heart muscle helps the heart to beat and this helps in passage of the electrical signal in the SA node. It is located on the top of the right atrium.
59) d) All the above are means by which the venous blood returns to the heart
Venous blood is the blood that has passed all the capillaries and tissues and goes into the veins to the right chambers of heart. It has low oxygen content. The skeletal muscle pump is very important which applies pressure within the veins and it leads to increased contraction of the surrounding skeletal muscle. This increased pressure helps the blood flow by the contraction of the muscle. The semilunar valves also helps in the blood flow in the heart.
60) a) High hydrostatic pressure of blood
With increase in the hydrostatic pressure in the blood, it helps the fluid to leave the blood vessel at the arterial end present in the capillary
61) d) both B and C
High colloidal pressure of the plasma proteins as well as hydrostatic pressure of the interstitial fluid are both responsible for fluid reabsorption into the blood vessel through the venous end of the capillary