Heinrich Müller (17 December 1820 – 10 May 1864) was a German

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

and professor at the

University of Würzburg The Julius Maximilian University of Würzburg (also referred to as the University of Würzburg, in German ''Julius-Maximilians-Universität Würzburg'') is a public research university in Würzburg, Germany. Founded in 1402, it is one of the ol ...

. He is best known for his work in

comparative anatomy Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species). The science began in the classical era, continuing in t ...

and his studies involving the eye. He was a native of

Castell A ''castell'' (: literally, ''castle'') is a human tower built traditionally at festivals in a part of Catalonia (Spain), now also found in the rest of Catalonia, in the Balearic islands and in the Valencian Community. At these festivals, s ...

Lower Franconia Lower Franconia (, ) is one of seven districts of Bavaria, Germany. The districts of Lower, Middle and Upper Franconia make up the region of Franconia. It consists of nine districts and 308 municipalities (including three cities). History After ...

. He was a student at several universities, being influenced by Ignaz Dollinger (1770–1841) in

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

, Friedrich Arnold (1803–1890) in

Freiburg Freiburg im Breisgau or simply Freiburg is the List of cities in Baden-Württemberg by population, fourth-largest city of the German state of Baden-Württemberg after Stuttgart, Mannheim and Karlsruhe. Its built-up area has a population of abou ...

, Jakob Henle (1809–1895) in

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

and

Carl von Rokitansky Baron Carl von Rokitansky (, ; 19 February 1804 – 23 July 1878) was a Czech-born Austrian empire, Austrian physician, pathologist, humanist philosopher and liberal politician, founder of the Viennese School of Medicine of the 19th century. He ...

(1804–1878) in

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

. In 1847 he received his habilitation at Würzburg, where from 1858 he served as a full professor of topographical and

. As an instructor, he also taught classes in systematic anatomy,

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

and

microscopy Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical mic ...

. In 1851 Müller noticed the red color in

rod cell Rod cells are photoreceptor cells in the retina of the eye that can function in lower light better than the other type of visual photoreceptor, cone cells. Rods are usually found concentrated at the outer edges of the retina and are used in ...

s now known as

rhodopsin Rhodopsin, also known as visual purple, is a protein encoded by the ''RHO'' gene and a G-protein-coupled receptor (GPCR). It is a light-sensitive receptor protein that triggers visual phototransduction in rod cells. Rhodopsin mediates dim ...

or visual purple, which is a pigment that is present in the rods of the

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

. However,

Franz Christian Boll Franz Boll (26 February 1849, Neubrandenburg – 19 December 1879, Rome) was a German physiologist and histologist. He was the son of Lutheran theologian Franz Boll (1805–1875). Boll studied medicine in Bonn, Heidelberg and Berlin, and in 1 ...

(1849–1879) is credited as the discoverer of rhodopsin because he was able to describe its "visual pigment cycle". Müller also described the fibers of

neuroglia Glia, also called glial cells (gliocytes) or neuroglia, are non- neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. The neuroglia make up ...

cells that make up the supporting framework of the retina. This structure was to become known as "Müller's fibers". Alongside Carl Bergmann, Müller is credited as co-discover, in 1854, of the anatomical site where vision is initiated . Müller moved various lights over his own and other observers' pupils and

sclera The sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective outer layer of the eye containing mainly collagen and some crucial elastic fiber. In the development of t ...

s, producing moving shadows of the retinal blood vessels from

motion parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

. This allowed him to reject the notion that conversion of light into vision happens closer to the light than the retinal blood vessels, as was accepted then. By careful measurement of the movements, he located the conversion of light into vision in the rods and cones. In 1856, with his colleague

Albert von Kölliker Albert von Kölliker (born Rudolf Albert Kölliker'';'' 6 July 1817 – 2 November 1905) was a Swiss anatomist, physiologist, and histologist. Biography Albert Kölliker was born in Zürich, Switzerland. His early education was carried on in Z ...

(1817–1905), Müller showed that an electric current was produced from each contraction of a frog's heart.

Additional eponyms

* "Müller's muscle": Circular portion of the

ciliary muscle The ciliary muscle is an intrinsic muscle of the eye formed as a ring of smooth muscleSchachar, Ronald A. (2012). "Anatomy and Physiology." (Chapter 4) . in the eye's middle layer, the uvea ( vascular layer). It controls accommodation for vie ...

of the eye. Also called "Rouget's muscle" after French

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and ...

Charles Marie Benjamin Rouget Charles Marie Benjamin Rouget (19 August 1824 – 1904, Paris) was a French physiologist born in Gisors, Gisors, Eure. He studied at the Collège Sainte-Barbe with medical training at hospitals in Paris. He was later a professor of physiology ...

(1824–1904), and sometimes "Müller-Rouget muscle" in honor of both men. * "Müller's muscle":

superior tarsal muscle The superior tarsal muscle is a smooth muscle adjoining the levator palpebrae superioris muscle muscle that helps to raise the upper eyelid. Structure The superior tarsal muscle originates on the underside of levator palpebrae superioris m ...

which is a

smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...

that adjoins the

levator palpebrae superioris muscle The levator palpebrae superioris () is the muscle in the orbit that elevates the upper eyelid. Structure The levator palpebrae superioris originates from inferior surface of the lesser wing of the sphenoid bone, just above the optic foramen. It ...

and helps to raise the upper eyelid. * "Müller's muscle": orbitalis muscle which is a

that crosses from the

infraorbital groove The infraorbital groove (or sulcus) is located in the middle of the posterior part of the orbital surface of the maxilla. Its function is to act as the passage of the infraorbital artery, the infraorbital vein, and the infraorbital nerve. Struc ...

and

inferior orbital fissure The inferior orbital fissure is a gap between the Greater wing of sphenoid bone, greater wing of sphenoid bone, and the maxilla. It connects the Orbit (anatomy), orbit (anteriorly) with the infratemporal fossa and pterygopalatine fossa (posterio ...

. * "Müller's trigone": Part of tuber cinereum folding over the

optic chiasm In neuroanatomy, the optic chiasm, or optic chiasma (; , ), is the part of the brain where the optic nerves cross. It is located at the bottom of the brain immediately inferior to the hypothalamus. The optic chiasm is found in all vertebrates, ...

of the brain. * "

Müller glia Müller glia, or Müller cells, are a type of retinal glial cells, first recognized and described by Heinrich Müller (physiologist), Heinrich Müller. They are found in the vertebrate retina, where they serve as support cells for the neurons, as ...

": Cells in the

which scaffold and nurture retinal

neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

Partial bibliography

* ''Nachweis der negativen Schwankung des Muskelstroms am naturlich sich contrahirenden Muskel''. Verhandlungen der Physikalisch-medizinische Gesellschaft in Würzburg, 1856, 6: 528–533. By Rudolph Albert von Kölliker (1817–1905) and Heinrich Müller. * ''Zur Histologie der Netzhaut. Zeitschrift für Wissenschaftliche Zoologie'', 1851, 3: 234–237. Discovery of visual purple. After his death, a large number of his works were published by Otto Becker (1828–1890) in a collection titled ''Heinrich Müller's gesammelte und hinterlassene Schriften zur Anatomie und Physiologie des Auges'' (Heinrich Müller's collected and bequeathed writings on the anatomy and physiology of the eye).Heinrich Müller - Bibliography
@

Who Named It ''Whonamedit?'' is an online English-language dictionary of medical eponyms and the people associated with their identification. Though it is a dictionary, many eponyms and persons are presented in extensive articles with comprehensive bibliograp ...

References

External Reference

''Heinrich Müller''
@

External links

* {{DEFAULTSORT:Muller, Heinrich 1820 births 1864 deaths People from Kitzingen (district) People from the Kingdom of Bavaria German anatomists Academic staff of the University of Würzburg