Baroreceptor: Difference between revisions

Jump to navigation Jump to search
No edit summary
m (Bot: Automated text replacement (-{{SIB}} + & -{{EH}} + & -{{EJ}} + & -{{Editor Help}} + & -{{Editor Join}} +))
 
Line 2: Line 2:
{{SI}}
{{SI}}


{{EH}}
 
==Overview==
==Overview==
'''Baroreceptors''' (or '''baroceptors''') in the [[human body]] detect the pressure of blood flowing through them, and can send messages to the [[central nervous system]] to increase or decrease [[total peripheral resistance]] and [[cardiac output]].
'''Baroreceptors''' (or '''baroceptors''') in the [[human body]] detect the pressure of blood flowing through them, and can send messages to the [[central nervous system]] to increase or decrease [[total peripheral resistance]] and [[cardiac output]].
Line 38: Line 38:
{{WikiDoc Help Menu}}
{{WikiDoc Help Menu}}
{{WikiDoc Sources}}
{{WikiDoc Sources}}
{{SIB}}

Latest revision as of 22:45, 8 August 2012

WikiDoc Resources for Baroreceptor

Articles

Most recent articles on Baroreceptor

Most cited articles on Baroreceptor

Review articles on Baroreceptor

Articles on Baroreceptor in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Baroreceptor

Images of Baroreceptor

Photos of Baroreceptor

Podcasts & MP3s on Baroreceptor

Videos on Baroreceptor

Evidence Based Medicine

Cochrane Collaboration on Baroreceptor

Bandolier on Baroreceptor

TRIP on Baroreceptor

Clinical Trials

Ongoing Trials on Baroreceptor at Clinical Trials.gov

Trial results on Baroreceptor

Clinical Trials on Baroreceptor at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Baroreceptor

NICE Guidance on Baroreceptor

NHS PRODIGY Guidance

FDA on Baroreceptor

CDC on Baroreceptor

Books

Books on Baroreceptor

News

Baroreceptor in the news

Be alerted to news on Baroreceptor

News trends on Baroreceptor

Commentary

Blogs on Baroreceptor

Definitions

Definitions of Baroreceptor

Patient Resources / Community

Patient resources on Baroreceptor

Discussion groups on Baroreceptor

Patient Handouts on Baroreceptor

Directions to Hospitals Treating Baroreceptor

Risk calculators and risk factors for Baroreceptor

Healthcare Provider Resources

Symptoms of Baroreceptor

Causes & Risk Factors for Baroreceptor

Diagnostic studies for Baroreceptor

Treatment of Baroreceptor

Continuing Medical Education (CME)

CME Programs on Baroreceptor

International

Baroreceptor en Espanol

Baroreceptor en Francais

Business

Baroreceptor in the Marketplace

Patents on Baroreceptor

Experimental / Informatics

List of terms related to Baroreceptor


Overview

Baroreceptors (or baroceptors) in the human body detect the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output.

Baroreceptors can be divided into two categories, high pressure arterial baroreceptors and low pressure baroreceptors (also known as cardiopulmonary receptors).

Arterial baroreceptors

There are baroreceptors present in the arch of the aorta, and the carotid sinuses of the left and right internal carotid arteries. In some sensitive people, due to baroreceptors, vigorous palpation of a carotid artery can cause severe bradycardia or even cardiac arrest.

Baroreceptors act to maintain mean arterial blood pressure to allow tissues to receive the right amount of blood.

See main article Baroreflex

If blood pressure falls, such as in shock, baroreceptor firing rate decreases. Signals from the carotid baroreceptors are sent via the glossopharyngeal nerve (cranial nerve IX). Signals from the aortic baroreceptors travel through the vagus nerve (cranial nerve X). Baroreceptors work by detecting the amount of stretch. The more the baroreceptor walls are stretched, the more frequently they generate action potentials. The arterial baroreceptors have a lower threshold of around 70 mmHg (typical arterial blood pressure is around 80-90 mmHg). Below this the receptors stop firing signals completely, any further decrease in pressure will cause no additional effect. At this low pressure however the response of chemoreceptors becomes more vigorous, especially below 60 mmHg.

Baroreceptors respond very quickly to maintain a stable blood pressure, but they only respond to short term changes. Over a period of days or weeks they will reset to a new value. Thus, in people with essential hypertension the baroreceptors behave as if the elevated blood pressure is normal and aim to maintain this high blood pressure.

Low pressure baroreceptors

These are found in the large veins and in the walls of the atria of the heart. The low pressure baroreceptors are involved with the regulation of blood volume. The blood volume determines the mean pressure throughout the system, in particular in the venous side where most of the blood is held.

The low pressure baroreceptors have both circulatory and renal effects, they produce changes in hormone secretion which have profound effects on the retention of salt and water and also influence intake of salt and water. The renal effects allow the receptors to change the mean pressure in the system in the long term.

Denervating these receptors 'fools' the body into thinking that we have too low blood volume and initiates mechanisms which retain fluid and so push up the blood pressure to a higher level than we would otherwise have.

External links

Template:Somatosensory system

Template:WikiDoc Sources