Bainbridge reflex

Jump to: navigation, search

WikiDoc Resources for Bainbridge reflex

Articles

Most recent articles on Bainbridge reflex

Most cited articles on Bainbridge reflex

Review articles on Bainbridge reflex

Articles on Bainbridge reflex in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Bainbridge reflex

Images of Bainbridge reflex

Photos of Bainbridge reflex

Podcasts & MP3s on Bainbridge reflex

Videos on Bainbridge reflex

Evidence Based Medicine

Cochrane Collaboration on Bainbridge reflex

Bandolier on Bainbridge reflex

TRIP on Bainbridge reflex

Clinical Trials

Ongoing Trials on Bainbridge reflex at Clinical Trials.gov

Trial results on Bainbridge reflex

Clinical Trials on Bainbridge reflex at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Bainbridge reflex

NICE Guidance on Bainbridge reflex

NHS PRODIGY Guidance

FDA on Bainbridge reflex

CDC on Bainbridge reflex

Books

Books on Bainbridge reflex

News

Bainbridge reflex in the news

Be alerted to news on Bainbridge reflex

News trends on Bainbridge reflex

Commentary

Blogs on Bainbridge reflex

Definitions

Definitions of Bainbridge reflex

Patient Resources / Community

Patient resources on Bainbridge reflex

Discussion groups on Bainbridge reflex

Patient Handouts on Bainbridge reflex

Directions to Hospitals Treating Bainbridge reflex

Risk calculators and risk factors for Bainbridge reflex

Healthcare Provider Resources

Symptoms of Bainbridge reflex

Causes & Risk Factors for Bainbridge reflex

Diagnostic studies for Bainbridge reflex

Treatment of Bainbridge reflex

Continuing Medical Education (CME)

CME Programs on Bainbridge reflex

International

Bainbridge reflex en Espanol

Bainbridge reflex en Francais

Business

Bainbridge reflex in the Marketplace

Patents on Bainbridge reflex

Experimental / Informatics

List of terms related to Bainbridge reflex

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]



The Bainbridge reflex is an increase in heart rate due to an increase in the blood volume. Increased blood volume is detected by stretch receptors located in both atria at the venoatrial junctions.

History

A scientist by the name of Francis Arthur Bainbridge reported this reflex in 1915 when he was experimenting on dogs. Bainbridge found that infusing blood or saline into the animal increased heart rate. This phenomenon occurred even if arterial blood pressure did not increase. He further observed that heart rate increased when venous pressure rose high enough to distend the right atrium, but denervation of the vagi to the heart eliminated these effects.

Control of Heart Rate

The Bainbridge reflex and the baroreceptor reflex act antagonistically to control heart rate. The baroreceptor reflex acts to decrease heart rate when blood pressure rises. When blood volume is increased, the Bainbridge reflex is dominant; when blood volume is decreased, the baroreceptor reflex is dominant.

Venous Return

As venous return increases, the pressure in the superior and inferior vena cavae increase. This results in an increase in the pressure of the right atrium, which stimulates the atrial stretch receptors. These receptors in turn signal the medullary control centers to increase sympathetic stimulation of the heart, leading to increased heart rate, a.k.a. tachycardia.

Increasing the heart rate serves to decrease the pressure in the superior and inferior vena cavae by drawing more blood out of the right atrium. This results in a decrease in atrial pressure, which serves to bring in more blood from the vena cavae, resulting in a decrease in the venous pressure of the great veins. This continues until right atrial blood pressure returns to normal levels, upon which the heart rate decreases to its original level.

Atrial Stretch Receptors

In the right atrium, the stretch receptors occur at the junction of the vena cavae. In the left atrium, the junction is at the pulmonary veins. Increasing stretch of the receptors stimulates both an increase in heart rate and a decrease in vasopressin (a.k.a. anti-diuretic hormone) secretion from posterior pituitary. This decrease in vasopressin secretion results in an increase in the volume of urine excreted, serving to lower blood pressure. In addition, stretching of atrial receptors increases secretion of atrial natriuretic peptide (ANP), which promotes increased water and sodium excretion through the urine.

References

  • Berne, R., Levy, M., Koeppen, B., & Stanton, B. (2004) Physiology, Fifth Edition. Elsevier, Inc.


Cardiology


Linked-in.jpg