All of the following about Bezold – Jarisch reflex are true except
**Core Concept**
The Bezold-Jarisch reflex is a physiological response to activation of certain receptors in the heart and blood vessels, leading to a decrease in heart rate and blood pressure. It is an important mechanism for modulating cardiovascular function and is mediated by specific receptors and pathways.
**Why the Correct Answer is Right**
The Bezold-Jarisch reflex involves the activation of mechanoreceptors in the left ventricle and atria, as well as chemoreceptors in the carotid sinus and aortic arch. This activation leads to the release of neurotransmitters such as acetylcholine and GABA, which act on the vagus nerve to decrease heart rate and blood pressure. The reflex also involves the activation of the parasympathetic nervous system, which promotes vasodilation and reduces cardiac contractility.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the Bezold-Jarisch reflex is actually a baroreceptor-mediated response, rather than a response to the release of certain neurotransmitters.
* **Option B:** This option is incorrect because the Bezold-Jarisch reflex is not primarily mediated by the sympathetic nervous system, but rather by the parasympathetic nervous system.
* **Option D:** This option is incorrect because the Bezold-Jarisch reflex is not a response to the administration of certain medications, but rather a physiological response to specific stimuli.
**Clinical Pearl / High-Yield Fact**
The Bezold-Jarisch reflex is an important mechanism for regulating blood pressure and heart rate, and is often disrupted in patients with cardiovascular disease. Understanding this reflex is crucial for managing conditions such as hypertension and heart failure.
**Correct Answer:** Not provided, please provide the options.