1.
ln isometric exercise all are increased except :
Correct Answer
D. Systemic vascular resistance
Explanation
In isometric exercise, the muscles contract without any change in length, which leads to an increase in blood pressure. As a result, mean arterial pressure, cardiac output, and heart rate all increase. However, systemic vascular resistance refers to the resistance to blood flow in the blood vessels, and in isometric exercise, it remains unchanged or may even decrease due to vasodilation. Therefore, all the options except systemic vascular resistance increase during isometric exercise.
2.
Aldosterone receptors are present in all except
Correct Answer
A. Liver
3.
Pulmonary circulation differs from systemic circulation
Correct Answer
B. Pulmonary vasoconstriction in hypoxia
Explanation
In hypoxia, the body's response is to constrict the blood vessels in the lungs, known as pulmonary vasoconstriction. This helps to redirect blood flow to areas of the lungs that are better oxygenated, improving the efficiency of gas exchange. This is in contrast to systemic circulation, where vasodilation occurs in response to hypoxia to increase blood flow to tissues and organs.
4.
Increase in threshold level of a nerve on application of a slowly rising sub-threshold stimulus is known as:
Correct Answer
B. Accomodation
Explanation
Accommodation refers to the increase in threshold level of a nerve when a slowly rising sub-threshold stimulus is applied. This phenomenon allows the nerve to adapt to the gradually increasing stimulus and eventually reach its threshold level, resulting in an action potential. This process is important for the nerve to properly respond to varying levels of stimuli and maintain its sensitivity.
5.
Which of the following is true about fourth heart sound ‘S4‘ :
Correct Answer
C. Heard during ventricular filling pHase
Explanation
S4 is heard during the last rapid filling phase of cardiac cycle.
6.
Broca’s area is concerned with:
Correct Answer
A. Word formation
Explanation
Broca's area is the motor speech area concerned with word formation.
7.
All of the following statements are true for ‘Intestinal Motility’ except:
Correct Answer
A. Does not depend on Gastric motility
Explanation
Intestinal motility is influenced by gastric motility. eg: Migratory motor complex, gastroileal reflex
8.
Which of the following hormone is not secreted by the kidney:
Correct Answer
B. Angiotensin I
Explanation
Angiotensin I is formed by action of Renin (secreted by kidney) on Angiotensinogen (secreted by liver).
9.
When a muscle cell is relaxed and intracellular ATP levels are normal, a crossbridge will remain in which of the following states?
Correct Answer
C. In the high-energy form, with ADP and Pi bound to it
Explanation
When a muscle cell is relaxed and intracellular ATP levels are normal, a crossbridge will remain in the high-energy form with ADP and Pi (inorganic phosphate) bound to it. This is because during muscle contraction, ATP is hydrolyzed into ADP and Pi, releasing energy that is used to power the movement of the crossbridge. In the relaxed state, the crossbridge is still bound to actin but is in the high-energy form, ready to undergo the power stroke and generate force when the muscle is stimulated to contract.
10.
Which of the following is true for the excitation-contraction coupling of all muscle types (skeletal, cardiac, and smooth)?
Correct Answer
D. A & c
Explanation
During excitation-contraction coupling in all muscle types, an action potential is generated, which causes calcium levels in the cytosol to increase. This increase in calcium levels then leads to the binding of calcium to troponin, resulting in the exposure of binding sites on actin. Subsequently, the thick and thin filaments slide past each other, leading to muscle contraction. Therefore, both options "a" (an action potential causes calcium levels in the cytosol to increase) and "c" (thick and thin filaments slide past each other) are true for the excitation-contraction coupling of all muscle types.