Franz Riegel was a German internist and gastroenterologist who was a native of Brückenau

Bad Brückenau

Bad Brückenau is a spa town in Bad Kissingen district in northern Bavaria. It is situated in the Rhön Mountains, 30 kilometers south of Fulda.-Geography:Bad Brückenau is located in the valley of the River Sinn, in the western part of the Rhön Mountains...

.

He studied medicine at the University of Würzburg

University of Würzburg

The University of Würzburg is a university in Würzburg, Germany, founded in 1402. The university is a member of the distinguished Coimbra Group.-Name:...

, and following graduation furthered his studies in Vienna

University of Vienna

The University of Vienna is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world...

 with Johann von Oppolzer

Johann Ritter von Oppolzer

Johann Ritter von Oppolzer was an Austrian physician born in Nové Hrady, Bohemia. He was the father of the astronomer Theodor von Oppolzer ....

 (1808-1871). Afterwards he returned to Würzburg

Würzburg

Würzburg is a city in the region of Franconia which lies in the northern tip of Bavaria, Germany. Located at the Main River, it is the capital of the Regierungsbezirk Lower Franconia. The regional dialect is Franconian....

 as an assistant to Heinrich von Bamberger

Heinrich von Bamberger

Heinrich von Bamberger was an Austrian pathologist from Prague.-Biography:...

 (1822-1888), and later Carl Gerhardt

Carl Jakob Adolf Christian Gerhardt

Carl Jakob Adolf Christian Gerhardt ; was a German internist born in Speyer....

 (1833-1902). In 1871 he was a lecturer of experimental pathology

Experimental pathology

Experimental pathology, also known as investigative pathology is the scientific study of disease processes through the microscopic or molecular examination of organs, tissues, cells, or body fluids from diseased organisms. It is closely related, both historically and in modern academic settings, to...

 at the University of Würzburg, and in 1874 became director of the Cologne

Cologne

Cologne is Germany's fourth-largest city , and is the largest city both in the Germany Federal State of North Rhine-Westphalia and within the Rhine-Ruhr Metropolitan Area, one of the major European metropolitan areas with more than ten million inhabitants.Cologne is located on both sides of the...

 city hospital. In 1879 he was appointed to the chair of medicine at the University of Giessen

University of Giessen

The University of Giessen is officially called the Justus Liebig University Giessen after its most famous faculty member, Justus von Liebig, the founder of modern agricultural chemistry and inventor of artificial fertiliser.-History:The University of Gießen is among the oldest institutions of...

, where he would remain until his death in 1904.

Riegel's research involved studies of the respiratory system

Respiratory system

The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...

, vasomotor

Vasomotor

Vasomotor refers to actions upon a blood vessel which alter its diameter. More specifically, it can refer to vasodilator action and vasoconstrictor action....

 influences, the effects of substances such as caffeine

Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...

, atropine

Atropine

Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...

 and jaborandi

Pilocarpus

Pilocarpus is a genus of about 13 species of plants belonging to the family Rutaceae, native to the neotropics of South America. Various species are important pharmacologically...

, conditions 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...

 and 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...

 in nephritis

Nephritis

Nephritis is inflammation of the nephrons in the kidneys. The word "nephritis" was imported from Latin, which took it from Greek: νεφρίτιδα. The word comes from the Greek νεφρός - nephro- meaning "of the kidney" and -itis meaning "inflammation"....

, et al. He is remembered for his extensive research of gastric disorders; his last written work discussing distinctions between hyperacidity and hypersecretion

Secretion

Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...

.

His best known written work was an 1896 book on gastroenterology

Gastroenterology

Gastroenterology is the branch of medicine whereby the digestive system and its disorders are studied. The name is a combination of three Ancient Greek words gaster , enteron , and logos...

 titled Die Erkrankungen des Magens (The Diseases of the Stomach), which was later translated into English.

• Associated eponym:
• Riegel's pulse: A pulse that diminishes in volume during expiration
  Exhalation
  Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....
  
  .