Mammalian kidney The Mammalian kidney is an osmoregulatory
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• Mammalian kidney • The Mammalian kidney is an osmoregulatory organ. • The mammalian kidney perform several function in lower are shared by other organ such • Skin and gall bladder in amphibians , gill in fishes. Anatomy of kidney • • The kidney is a bean –shaped organ in all vertebrate. The kidney are at the lower of abdominal cavity. The right is generally smaller and lower than left. Each kidney weight 125 -170 g in male and 115 -15 g in female.
o The Outer layer of the kidney is known as cortex. o The inner layer, medulla send papillae projecting into renal pelvis. o The pelvis give rise to ureter, which empties into the urinary bladder via urethra, o Which leads to the end penis in males and into the vulva of the female.
The function of kidney • Excretion of metabolic waste product and foreign, chemical • Regulation of water and electrolyte balance. • Regulation of atrial pressure. • Regulation of Acid base balance. • Secretion , metabolism, and excretion of hormone. • Regulation of blood glucose level.
Functional unit of kidney: (Nephron) • A nephron is a basic unit of structure in kidney which can form urine • In both kidney there are 2. 6 millions nephrons • The total length of nephron including collecting duct in 45. 65 mm. • There are 2 types of nephron 1: Cortical nephron 2: Juxtamedullary nephron. • Cortical nephron have their glomeruli in the outer cortex and relative short loop of henle. • The nephron comprises of about 85% of the nephron in the kidney • Juxtamedullary nephron have their glomeruli in the inner part of cortex and long loop of henle that deeply into the medulla.
Parts of nephron: • Glomerulus • Renal tubules • Bowman’s capsule • Proximal convoluted tubules • Loop of henle ( Ascending or descending) • Collecting tubule
Basic function of nephron • The Basic function of nephron do to clear and clean the blood plasma substance this occurs in following steps: • Filtration: • Because of high pressure in the glomerulus its act as an arterial and of the capillary, causing filtration of large portion of plasma out of glomerulus and into the Bowman’s capsule.
Selective reabsorption: As the filtered flow through the tubules, the unwanted substance fail to be reabsorb, while the wanted substance (water and electrolyte) are reabsorbed and break into plasma of the per tubular capillaries. Secretion Few substance secrete from the plasma directly through the epithelium cells lining the tubules into the tubular lumen the urine is formed.
