Urinary

• Urinary system is the excretion of waste from filtering blood.

  The four organs of the system are

  Kidney: Filter

  Ureter: Transport

  Bladder: Storage

  Urethra: Transport/excrete 
• Micturition reflex is the release of urine.

  Bladder fills with urine which activates the stretch receptors → Brain → Relax involuntary sphincter → Relax voluntary sphincter → Urine leaving body → Reflex cycle until bladder is full again
• Process of urine formation: Filtration, Reabsorption, Secretion
• Filtration: Blood filters into the glomerulus capsule (Cortex) Increase in pressure filters small molecules (Excludes: Proteins, red blood cells)
• Reabsorption: Located in renal tubule (Medulla), Substances move back into blood (Water, Glucose, Solutes)
• Secreting: Waste/toxins secreted into renal tubule
• Urine travels through renal tubule (Medulla) -> the collecting ducts -> renal pyramids -> Renal pelvis -> Ureter -> Bladder -> Urethra
• Function of urinary system: Excretion of waste from filtering of blood. The waste product creates urine
• Bladder is made up of transitional epithelium tissue. Full bladder makes the tissue stretch (Stratified -> Simple)
• ADH (Anti diuretic hormone): Prevents release of water (and Na+).

  Stimulus increase -> Osmolarity increase (Saltiness in blood) -> Receptors detect too much salt -> Control centre increases release of ADH to stop the release of water from body. Response decreases in osmolarity
• ADH targets increase of reabsorption to keep water and decrease osmolarity