Library · Physiology
Blood pressure regulation
Make it clearer
Blood pressure changes all the time, and the body corrects it without our noticing. The alarm is sounded by the baroreceptors: nerve endings that are stimulated when the structure they sit in stretches.
Two groups of them do this job. They sit in the carotid sinus, a widening of the artery in the neck, and in the aortic arch, the curve of the large artery that leaves the heart. When pressure stretches the wall, they fire more often. Think of a stretch sensor: the more it stretches, the more it signals. That message reaches the medulla oblongata, the lower part of the brainstem.
The medulla responds by raising parasympathetic tone and reining in sympathetic outflow. The heart beats more slowly and with less force, and the arteries dilate.
This is a short-term fix. If high pressure sticks around, the reflex itself resets.
In brief
Blood pressure is corrected by a negative feedback loop monitored by baroreceptors.
Those in the carotid sinus and the aortic arch fire faster when pressure stretches the wall, and they signal the medulla oblongata.
A stretch sensor in the artery wall: the more it stretches, the more it signals.
The medulla raises parasympathetic tone and reins in sympathetic outflow: heart rate and contractility fall, and the arteries dilate.
This is short-term control: if high pressure persists, the reflex resets.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Baroreceptors, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated