What term describes the phenomenon wherein decreased BP causes a reflex SNS response with increased pulse, increased contractility, and vasoconstriction; and increased BP causes reflex vagal responses resulting in decreased heart rate and passive vasodilation in the systemic arterioles?

Correct Answer: A

Rationale: The correct answer is A: Baroreflex. The baroreflex is a physiological mechanism that helps regulate blood pressure by responding to changes in pressure. When blood pressure decreases, the baroreceptors detect this change and trigger a sympathetic nervous system (SNS) response, leading to increased heart rate, contractility, and vasoconstriction to raise blood pressure. Conversely, when blood pressure increases, the baroreceptors trigger a parasympathetic (vagal) response, resulting in decreased heart rate and vasodilation to lower blood pressure. Summary of other choices: B: Cheyne-Stokes breathing is a pattern of breathing characterized by periodic waxing and waning of tidal volume. C: Frank-Starling Law describes the relationship between preload and stroke volume, not the response to changes in blood pressure. D: Starling reflex is not a recognized physiological mechanism related to blood pressure regulation.

Correct Answer: A

Rationale: The correct answer is A: Interventricular septum. This structure separates the left and right sides of the heart, forming a barrier between the two ventricles. It ensures that oxygenated and deoxygenated blood do not mix within the heart chambers. The endocardium (B) is the inner layer of the heart's chambers, the epicardium (C) is the outer layer of the heart, and the pericardium (D) is the sac surrounding the heart. These structures do not specifically separate the left and right sides of the heart.

Correct Answer: A

Rationale: The correct answer is A: Systole. During systole, the heart muscle contracts to pump blood out of the chambers. This phase is essential for delivering oxygenated blood to the body. Diastole (B) is the relaxation phase when the heart fills with blood. Contractility (C) refers to the heart's ability to contract, not a specific phase. Afterload (D) is the pressure the heart must pump against to eject blood, not a phase of the cardiac cycle. Therefore, the term that specifically refers to the contraction phase of the heart is systole.

Correct Answer: A

Rationale: Atherosclerosis is the correct answer because it specifically refers to the accumulation of fatty deposits in arteries, causing reduced blood flow. Arteriosclerosis is a general term for thickening and hardening of arteries, not necessarily due to fatty deposits. Aneurysm is a localized, abnormal dilation of a blood vessel, not related to fatty deposits. Thrombosis is the formation of a blood clot within a blood vessel, not the accumulation of fatty deposits.

Correct Answer: A

Rationale: Asthma is the correct answer because it is a condition characterized by inflammation and narrowing of the airways, leading to difficulty in breathing. This is due to various triggers causing the airways to become inflamed, swollen, and produce excess mucus, resulting in constriction and breathing difficulties. Bronchitis, Pleurisy, and Tuberculosis do not directly involve narrowing of the airways as their primary mechanism, making them incorrect choices. Bronchitis is inflammation of the bronchial tubes, Pleurisy is inflammation of the lining around the lungs, and Tuberculosis is a bacterial infection primarily affecting the lungs.