Answer: Sensing arterial stretch and triggering reflex changes in heart rate and vessel diameter.
- A Directly sensing blood oxygen levels and adjusting breathing rate as widely reported
- B Sensing arterial stretch and triggering reflex changes in heart rate and vessel diameter
- C Releasing aldosterone in response to falling blood sodium levels in standard reference material
- D Producing erythropoietin in response to low oxygen delivery under most conditions studied
Correct answer: B. Sensing arterial stretch and triggering reflex changes in heart rate and vessel diameter
Explanation: Baroreceptors detect stretch in arterial walls caused by changes in blood pressure and send signals to the medulla, triggering reflex changes in heart rate and vessel diameter to maintain blood pressure.
A single ECG cycle: the P wave marks atrial depolarisation (contraction signal), the large QRS complex marks ventricular depolarisation, and the T wave marks ventricular repolarisation (recovery) before the next cycle begins.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.