EXCRETORY SYSTEM
Mammalian kidney is
metanephric.
Right kidney lower than
left because of liver in human. Opposite in case of rabbit
Archeonephric- Schistomata eg. Hag fish
Pronephric- Fish and tadpole stage
Mesonephric- Adult amphibia an lung fish
Metanephric- Reptiles, Aves and Birds
Kidney receive 25% of
cardiac output per minute
Glomerulus
Bowman’s capsule formed
by simple squamous epithelial cells. Boot-shaped podocyte cells present in
visceral layer
PCT- - simple cudoidal epithelium & brush
border cells
- Maximum absorption
Loop of Henle
- Decending limb- squamous
epithelium
- Water absorption
- Ascending limb- cuboidial
epithelium
- Ions absorption no water entry
DCT
- Reabsorption of water under
influence of ADH
Deficiency of ADH causes
excess urination called dieresis (insipidus diabetes)
All excretory organ
originated from mesoderm except urinary bladder originated from endoderm.
Urinary baldder lined with trantitional epithelium.
Aminotelic- Unio, Limax, Star fish
Ammonotelic- Bony Fish, tadpole
Uricotelic- Birds, inscets, reptiles
Ureotelic- Mammals, frog, cartilaginous fish
Due to: Urine yellow(urocrome),
faeces brown (stercobilin)
Rabbit coprophagus
Hormones secreted by
kidney-
- Renin
- Erythropoietin
- Vit. D
Urethrisis common in female
Net filtration pressure=
GHP-BOP-CHP
= 75-20-20
25 mm of hg
Inlammation of urinary
bladder- Cystitis
PCT absorb- AG VET
(Amino acid, Glucose, Vitamin) Water, Na+, k+, Ca+ absorption
DCT absorb- ADH
(water,) Aldesterone(Na+), Active absorption of Na+ & Secretion of K+
PCT secrete- Cretaine,
Hydrogen, Hippuric acid, ammonia
DCT secrete-
Bicarbonate, Potassium, Hydrogen, Ammonia