Francis Arthur Bainbridge FRS FRCP (29 July 1874 – 27 October 1921) was an English physiologist.

Bainbridge was born in Stockton-on-Tees

Stockton-on-Tees

Stockton-on-Tees is a market town in north east England. It is the major settlement in the unitary authority and borough of Stockton-on-Tees. For ceremonial purposes, the borough is split between County Durham and North Yorkshire as it also incorporates a number of smaller towns including...

 in 1874 and educated at The Leys School

The Leys School

The Leys School is a co-educational Independent school, located in Cambridge, England, and is a day and boarding school for about 550 pupils aged between 11 and 18 years...

. He entered Trinity College, Cambridge

Trinity College, Cambridge

Trinity College is a constituent college of the University of Cambridge. Trinity has more members than any other college in Cambridge or Oxford, with around 700 undergraduates, 430 graduates, and over 170 Fellows...

 in 1893, graduating BA in 1896 and earning a doctorate in 1904. In 1911 he became a professor of physiology at Durham University

Durham University

The University of Durham, commonly known as Durham University, is a university in Durham, England. It was founded by Act of Parliament in 1832 and granted a Royal Charter in 1837...

. In 1915 he attained the chair of physiology at St. Bartholomew's Hospital, where he remained for the rest of his life.

Bainbridge is best remembered for showing that an increase in pressure on the venous side of the heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 resulted in an increased heart rate due to denervation of vagal influences to the heart. The eponymous Bainbridge reflex

Bainbridge reflex

The Bainbridge reflex, also called the atrial reflex, is an increase in heart rate due to an increase in central venous pressure. Increased blood volume is detected by stretch receptors located in both atria at the venoatrial junctions.-History:...

is named after him, which is an increased heart rate due to an increase of the right atrial pressure. Bainbridge's findings contradicted Marey's Law, which stated that an increase in blood pressure

Blood pressure

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

 caused a lowering of the heart rate. Marey's Law was devised in 1861 by French physiologist Étienne-Jules Marey

Étienne-Jules Marey

Étienne-Jules Marey was a French scientist and chronophotographer.His work was significant in the development of cardiology, physical instrumentation, aviation, cinematography and the science of labor photography...

 (1830–1904).

Bainbridge also made important contributions regarding the study of the mechanism of lymph

Lymph

Lymph is considered a part of the interstitial fluid, the fluid which lies in the interstices of all body tissues. Interstitial fluid becomes lymph when it enters a lymph capillary...

 formation, and filtration

Filtration

Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...

 properties of the glomeruli in the kidneys. His most popular publications were Essentials of Physiology (1914) and Physiology of Muscular Exercise (1919).

He was elected a Fellow of the Royal Society in May 1919