Anatomical structure of the kidney and nephron

The urinary system of a person provides removal of nitrogenous slags from the body, formed during metabolism, and fluid, regulates blood pressure, the volume of circulating blood, acid-base balance, electrolyte balance. The central organs of the urinary system are the kidneys.

Consider the structure of the kidney. The kidneys are symmetrically located on both sides of the spine at the level of the XII thoracic to I-II lumbar vertebrae, retroperitoneal, surrounded by a thick layer of adipose tissue. In each kidney, the front and back surfaces, the upper and lower poles, the side and middle side are distinguished. Through the gate to the kidney enters and exits the vascular-neural bundle. The right kidney is located slightly lower than the left one, which is connected with the liver located above. The structure of the kidney allows its limited movement in an upright position. The position of the kidneys depends on the type of constitution of a person (hypersthenic, asthenic or normostenic). The kidneys enter the renal pelvis, large and small calyxes, where the tips of the kidney pyramids are in the form of papillae. On the surface of the papilla there are small holes through which urine is released.

The internal structure of the kidney is quite complicated. Nephron is the main structural unit of the kidneys that provides their work. The number of nephrons in both kidneys reaches 3-4 million. The nephron consists of a vascular glomerulus, a capsule and a renal tubule.

The structure of the kidney and nephron

There are two types of nephrons - superficial or cortical and deep or juxtaglomerular. In juxtaglomerular glomeruli there is a long loop of Henle that ends in the renal papilla. Capillaries of the glomeruli are covered with endothelium with pores, through which ultrafiltration of urine occurs. Capillaries of the glomeruli have a basal membrane. Epithelial cells resemble pads with processes that cover the capillary from the outside. The processes form a basal membrane, it plays a crucial role in the filtration of urine and other functions of the kidneys.

The vascular glomerulus of the kidneys is formed by capillaries into which the leading vessels, the diverting arteriola and the secondary capillary mesh feeding the tubule are separated. In the juxtaglomerular apparatus, special cells that produce renin are concentrated. This substance takes an active part in maintaining the level of blood pressure. Most of the tubules are located in the medulla of the kidneys. Due to the fact that the outflowing vessel is significantly already leading, a relatively high pressure (about 60 mm Hg) is created in the glomeruli and all the flowing blood is filtered. The initial part of the tubule forms around the glomerulus a capsule of Shumlyansky-Bowman. The glomerulus with the capsule is called the kidney or malpighian corpuscle.

The urinary canaliculus has a complex structure. Direct sections of the tubules, Henle's loops, and the urinal tubes are located in the medulla, and the sinuous sections of the tubules are located near the glomeruli and form a cortical layer of the kidney along with them.

The structure of the kidney ensures its continuous work. At the same time, some of the glomeruli are working, and the other is at rest. All the blood in the human body flows through the kidneys within one hour. Over droughts through the kidneys passes 1500-2000 liters of blood. The constituent elements of the urine mostly fall into the kidneys with blood, but some form directly in the kidney itself, for example, ammonia and gipuric acid.

We examined the structure of the kidney - the main organ of the urinary system, which ensures the removal of metabolic products and excess fluid from the body, as well as regulating the internal homeostasis of the human body.