This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Which of the following physiological change take place by Bainbridge reflex? \nSelect and explain. \nA. Increase in HR, B. Decrease in HR, C. Increase in BP, D. Distension of large somatic veins', 'role': 'user'}, {'content': "Answer: A \nExplanation: Atrial A and B receptors are located at the venoatrial junctions and have distinct functions. Type A receptors react primarily to hea rate but adapt to long-term changes in atrial volume. Type B receptors increase their discharge during atrial distension. C fibers arise from receptors scattered through the atria; these discharge with a low frequency and respond with increased discharge to increase in atrial pressure. The A and B receptors are thought to mediate the increase in hea rate associated with atrial distension (such as can occur with intravenous infusions) known as the Bainbridge reflex. In contrast, activation of atrial C fibers generally produces a vasodepressor effect (bradycardia and peripheral vasodilation). Ref: Hoit B.D., Walsh R.A. (2011). Chapter 5. Normal Physiology of the Cardiovascular System. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.", 'role': 'assistant'}]