CH33 REGULATION OF CONTENT (done)

Importance of water content regulation

maintain water potential in blod and tissue fluid constant, stable environment for cells to function properly

Urinary system

Urination: bladder contracts, sphincter muscles relax

Le kidney

Cortex(outer)
Medulla(inner)
pelvis(central chamber which connects to ureter)
Nephrons: in cortex and medulla

Le Nephron

Ball-like Bowman's capsule --> proximal convoluted tublue --> loop of Henle --> distal convoulted tuble --> collecting duct
afferent arteriole: before glomerulus
efferent: after

Urine formation

  1. Ultrafiltration
  2. Reabsorption

Ultrafiltration

Reabsorption

Adaptive features

Functions of Kidneys

Osmoregulation

Low water potential (e.g. sweating)

High water potential

Excretion: removal of metabolic wastes from the body

Kidney failure and dialysis machines

Kidney failure: <50 % of normal level

Dialysis tubing: differentially permeable
Dialysis fluid: no urea
Blood passes through the dialysis tubing, urea in blood diffuses out into the dialysis fluid along the concentration gradient

Features: