Kidneys

The building is the kidneys'  composed tubulous gland  ', where each of the tubules bears the designation'  nephron . Nephron also functionally follows the collecting and drainage channels.

The kidney has a specifically  bean shape,  where we recognize:


 *  'Facies anterior' ,
 *  'Facies posterior' ,
 *  'Extremitas Superior' ,
 *  'Extremitas inferior' ,
 *  'Margo lateralis et medialis.

On Margo Medialis we find a packed place, Hilum renale.

The kidney dimensions are (length) 10 -  12  'cm x (width) 5 -' '6'  cm x (thickness)  '3.5' '' - 4 cm. One kidney is able to hold its function when a second -sided kidney defect.

kidney building

 * Capsula fibrosa,
 * Cortex Renalis,
 * Medulla Renalis.

function

 * Primary urine formation and adjustment to definitive urine (hypertonic);
 * urine excretion (mainly urea), metabolites;
 * maintenance homeostasis, regulation  acid -base balance;
 * Endocrine function (renin, erythropoetin, 1,2-dihydroxycholecoferol);
 * regulation of water volume in the body;
 * exclusion of toxic substances, medicines and other metabolites;
 * regulation blood pressure.

Regulatory mechanisms

 * Autonomous nerves (mainly effect on blood vessel contractility);
 * Endocrine regulation (the basis is juxtaglomerular apparatus).

compensatory mechanisms
]


 * '' 'Myogenic authegulation' ' - the vessel responds to pressure change - when pressure drops, dilatation of VAS Aferens occurs and when the vasoconstriction pressure increases. Myogenic regulation is mediated by endothels.
 * '' ' This is made up of three types of cells:
 *  juxtaglomerular cells ;
 * '' Macula DENSA 'cells' - register a change in ion concentration;
 *  juxtaglomerular mesangial cells . JGA produces Renin (the stimulus to its synthesis is' 'pressure drop' 'in vas Aferens or' 'decrease in the concentration of ions') that allows the conversion of angiotensinogen to

 'angiotensin I.' , which is converted into  'angiotensin II'    '. He has  vasoconstrictive  properties mainly in vas effeers. In addition, it stimulates the creation of '' 'aldosterone (ALD)' '.


 *  'It affects the filter fraction'  - the filter fraction is the ratio between glomerular filtration and plasma inflow in the kidneys (physiologically approx.  '15-20 % ').

The blood vessels of the kidneys



 * The blood circulation of the kidneys is about 20 % of the minute cardiac dispensing - this large tributary has greater functional significance than circulation that brings nutrients to the kidneys. High pressure in VAS Aferens exceeds oncotic throughout the glomerulus.
 * '' 'Skimming Effect' ' - Department Erythrocyte from Plasma. Erythrocytes pass through wider sinus and plasma filters with capillaries.


 * 1)  'The arteries' 
 * 2) *A. & nbsp; Renalis dextra et sinistra - each divided into Rami Anteriores (finally 4 branches for front 4 kidney segments) and Ramus posterior (for the rear segment).
 * 3) *A. & nbsp; Renalis Accesoria - occurs in 30 %.
 * 4) * Branch for bark : Arteriae Lobares, Arteriae Interlobares, Arteriae Arcuatae, Arteriae Interlobulares - of which Arteriae Glomerulares Aferentes/Efferentes, Peritubular Capillary Greed.
 * 5) * Branching for pulp : The basis is arteriae glomerulares Efferentes, then arteriae rectae.
 * 6)  'Venous drain'  '
 * 7) *'' The bark veins': venulae stellatae - peritubular capillary riverbed - Venae Interlobulares - Venae Arcuatae - Venae Interlobares - Vena Renalis.
 * 8) * The veins of the pulp : venulae rectae - venae arcuatae.
 * 9) Lymph
 * 10) *Lymph is collected in three knitting, from the peritubular, subcapsular and z 'capsula adiposa' ', and comes to' 'nodi lymphatici lumbales'.
 * 11)   Nerves  
 * 12) *comes from the plenalis plexus = plotted by sympathetic, parasympathetic and sensitive fibers going around 'a. "Renalis". Autonomous fibers have a vasomotor function, sensitive fibers mainly innervate ''

Position and fixation of kidneys

 * Are stored in Retroperitoneal space at the height of Th12 -l2, the upper third lies on the diaphragm, the lower two -thirds on [m. & Nbsp; quadratus lumborum]];
 * The right one is shifted by about half the length of the vertebra below;
 * Hilum Renale is skeletotopically projected to L1 level.



related articles

 * Kidney (histological preparation)]
 * Nephron
 * Kidney function in maintaining acid -base balance
 * Tubular processes
 * Blood flow through the kidneys and its self -regulation

used literature






[Category: Anatomy]]