Nephron

A nephron (from Greek νεφρός kidney) is the functional subunit of the kidney. It consists of:

• The renal corpuscle ( Malpighian corpuscle, named after Marcello Malpighi ) and
• Connected to it renal tubules ( tubule ).

Each kidney has about a million people of these subunits.

In the nephrons primary urine is continuously filtered from the blood in the area of the renal corpuscle. Certain substances are then absorbed in the tubules and secreted, causing the actual urine ( as a secondary or final urine ) forms.

Overview of the tubule

The renal tubule is divided into main piece (proximal tubule ), transition piece ( Intermediärtubulus or tubule attenuatus ) and middle part (distal tubule ). The straight sections of the renal tubules and the transition piece form a loop, which is called the loop of Henle (after Jacob Henle, lat Ansa nephroni ). The loop of Henle exists only in mammals and birds, it is obviously necessary in order to form an over the blood hyperosmotic urine can, because vertebrates without loop of Henle are not capable of doing.

Verbindungstubulus and collecting duct are embryologically different origin and therefore not part of the nephron. However, they constitute a functional unit with the tubules of the nephron. The distal tubule is distal with respect to the nephron.

In the nomenclature of the Tubulussystems anatomical and physiological aspects may be taken into account, which leads to different but complementary divisions.

Both the proximal and the distal tubule are each in a " aufgeknäuelten " part, pars convoluta or pars contorta, and a " straight " part, pars recta, divided. The Partes rectae both tubules and the Intermediärtubulus are grouped functionally to the loop of Henle. The pars recta of the distal tubule is often referred to only as thick ascending limb of Henle's loop, whereas then the distal tubule only the pars convoluta (also known as early - distal) or even (as late - distal) of Verbindungstubulus and the beginning of collection tube to be understood. The assignment of the Verbindungstubulus to center piece or collection tube is not uniform. Here it is assigned to the manifold.

The following table compares German names, the names according to the Nomina Anatomica, other organizations, international abbreviations, and anatomical location.

Inter alia, absorption or secretion of uric acid by anion with the help of the proximal tubule cells

Mean nephrons: medullary rays, outer strip outer Mark Juxtamedulläre nephrons outdoor strip outer Mark

Juxtamedulläre and medium nephrons: Interior strips outer Mark, inner Mark

Juxtamedulläre and medium nephrons: Outside Mark, transition bark

Main piece

The main piece ( tubule Proximal ) first runs tortuous ( tubule Proximal tubule ) and then straight ( tubule Proximal rectus ) in the renal medulla.

Here the valuable compounds present in the primary urine (such as glucose, amino acids, electrolytes), can be recovered. Also, here are some pollutants are actively discharged.

Transfer guide

The transition piece ( tubule attenuatus ) takes first in the direction of the renal medulla and then turn back around towards the bark. Here the urine is extracted mainly water.

Centerpiece

The middle piece ( tubule distalis ) begins even in the renal medulla, and pre- as a straight tube ( tubule Distal rectus ) in the renal cortex. Here is again followed by a winding section ( tubule Distal tubule ), which opens into a collecting tube.

In the distal tubule, the urine NaCl is extracted and released into the renal medulla, where NaCl passes through the capillaries back into the bloodstream. Here you will find active transport via ion channels rather than Na is actively transported out, Cl - moves passively by.