The nephron is the microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and an encompassing Bowman's capsule. The renal tubule extends from the capsule. The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 0.8 to 1.5 million nephrons in each kidney. Blood is filtered as it passes through three layers: the endothelial cells of the capillary wall, its basement membrane, and between the foot processes of the podocytes of the lining of the capsule. The tubule has adjacent peritubular capillaries that run between the descending and ascending portions of the tubule. As the fluid from the capsule flows down into the tubule, it is processed by the epithelial cells lining the tubule: water is reabsorbed and substances are exchanged ; first with the interstitial fluid outside the tubules, and then into the plasma in the adjacent peritubular capillaries through the endothelial cells lining that capillary. This process regulates the volume of body fluid as well as levels of many body substances. At the end of the tubule, the remaining fluid—urine—exits: it is composed of water, metabolic waste, and toxins.
Friedrich Gustav Jakob Henle was a German physician, pathologist, and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay, "On Miasma and Contagia," was an early argument for the germ theory of disease. He was an important figure in the development of modern medicine.
In the kidney, the loop of Henle is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after its discoverer, the German anatomist Friedrich Gustav Jakob Henle, the loop of Henle's main function is to create a concentration gradient in the medulla of the kidney.
A fascia is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilizes, encloses, and separates muscles and other internal organs. Fascia is classified by layer, as superficial fascia, deep fascia, and visceral or parietal fascia, or by its function and anatomical location.
Albert von Kölliker was a Swiss anatomist, physiologist, and histologist.
In anatomy, serous membrane is a smooth tissue membrane consisting of two layers of mesothelium, which secrete serous fluid. The inner layer that covers organs (viscera) in body cavities is called the visceral membrane. A second layer of epithelial cells of the serous membrane, called the parietal layer, lines the body wall. Between the two layers is a potential space, mostly empty except for a few milliliters of lubricating serous fluid that is secreted by the two serous membranes.
Renal pyramids are cone-shaped tissues of the kidney. In humans, the renal medulla is made up of 10 to 18 of these conical subdivisions. The broad base of each pyramid faces the renal cortex, and its apex, or papilla, points internally towards the pelvis. The pyramids appear striped because they are formed by straight parallel segments of nephrons' Loops of Henle and collecting ducts. The base of each pyramid originates at the corticomedullary border and the apex terminates in a papilla, which lies within a minor calyx, made of parallel bundles of urine collecting tubules.
The tunica intima, or intima for short, is the innermost tunica (layer) of an artery or vein. It is made up of one layer of endothelial cells and is supported by an internal elastic lamina. The endothelial cells are in direct contact with the blood flow.
In human anatomy, the palmar or volar interossei are three small, unipennate muscles in the hand that lie between the metacarpal bones and are attached to the index, ring, and little fingers. They are smaller than the dorsal interossei of the hand.
Friedrich Sigmund Merkel was a leading German anatomist and histopathologist of the late 19th century. In 1875, he provided the first full description of Tastzellen which occur in the skin of all vertebrates. They were subsequently given the eponym "Merkel cells" in 1878 by Robert Bonnet (1851–1921).
In anatomy, the abdominal wall represents the boundaries of the abdominal cavity. The abdominal wall is split into the posterior (back), lateral (sides) and anterior (front) walls.
In the blood supply of the kidney, the straight arterioles of kidney are a series of straight capillaries in the medulla. They lie parallel to the loop of Henle.
The inner end of the external acoustic meatus is closed, in the recent state, by the tympanic membrane; the upper limit of its outer orifice is formed by the posterior root of the zygomatic process, immediately below which there is sometimes seen a small spine, the suprameatal spine also called the spine of Henle, situated at the upper and posterior part of the orifice.
The endoneurium is a layer of delicate connective tissue around the myelin sheath of each myelinated nerve fiber in the peripheral nervous system. Its component cells are called endoneurial cells. The endoneuria with their enclosed nerve fibers are bundled into groups called nerve fascicles, each fascicle within its own protective sheath called a perineurium. In sufficiently large nerves multiple fascicles, each with its blood supply and fatty tissue, may be bundled within yet another sheath, the epineurium.
Within the nephron of the kidney, the descending limb of loop of Henle is the portion of the renal tubule constituting the first part of the loop of Henle.
Within the nephron of the kidney, the ascending limb of the loop of Henle is a segment of the heterogenous loop of Henle downstream of the descending limb, after the sharp bend of the loop. This part of the renal tubule is divided into a thin and thick ascending limb; the thick portion is also known as the distal straight tubule, in contrast with the distal convoluted tubule downstream.
Crypts of Henle are microscopic pockets found in scattered sections of the conjunctiva around the eyeball. They are responsible for secreting mucin, a proteinous substance that makes up the inner layer of tears. It coats the cornea to provide a hydrophilic layer that allows for even distribution of the tear film. The layer of mucin allows tears to glide evenly across the eye’s surface. The crypts of Henle are named after German anatomist Friedrich Gustav Jakob Henle (1809-1885).
The inner or epidermic coat of the hair follicle is closely adherent to the root of the hair, and consists of two strata named respectively the outer and inner root sheaths.
In human anatomy, the adductor minimus is a small and flat skeletal muscle in the thigh which constitutes the upper, lateral part of the adductor magnus muscle.
