• Human anatomy

    EXCRETORY SYSTEM IN HUMAN

    Except for urinary bladder which is endodermal in origin, the whole excretory system is Except urinary bladder which is endodermal in origin, the whole excretory system is Except mesodermal. In human the kidney is retroperitoneal i.e., the kidney is located outside the coelomic cavity and is covered by peritoneum (coelomic epithelium) from the ventral side only. The size of each kidney is ~10 cm and it weighs is ~150 g. The two kidneys are asymmetrical, the Rt. being posterior to the Lt. Each kidney is bean-shaped with a groove (hilus) in the middle. The hilus is absent in frog’s kidney. The white fibrous connective tissue-covering around kidney is called renal…

  • Human anatomy

    Urine Formation

    3−steps are involved in the formation of urine A) Ultra filtration It is filtration under pressure. Glomerular capillary pressure (45 mm of Hg) favours filtration. The Colloidal osmotic pressure (due to plasma proteins, particularly albumin) acts against filteration. Its value is ~20 mm of Hg. The Capsular filtrate pressure, due to the glomerular filtrate in the Bowman’s capsule, also acts against filtration. Its value is ~10 mm of Hg. Net filtration pressure = 45 − (20+10) mm of Hg = 15 mm of Hg or 10 − 20 mm of Hg. Only 1/5 of plasma (20%) gets filtered from glomerulus per unit time. It is about 125 ml per minute.…