The Pathway of ADH The Effect of SIADH Larry Li

Production of ADH ADH is released from the pituitary gland in response to dehydration Produced by neurosecretory cells, ADH is put in vesicles and sent through ion channels to the hypothalmus It then travels through the pituitary stalk to the pituitary gland ADH ADH ADH ADH ADH ADH ADH

Secretion of ADH ADH is stored in the pituitary gland until the lack of water in the human body triggers it. In the cell, ADH causes the kidney to increase in water permeability. Results in reabsorption of water and concentrated urine excretion. ADH ADH ADH ADH ADH ADH

A water channel, aquaporin-2, allows for the moving of water This allows for reabsorption With ADH, the loss of water is reduced by less urine being formed Reabsorption of Water

End of Production of ADH With the aquaporins active, the plasma osmolarity decreases and the urine osmolarity increases. The dilution of plasma is detected by receptors The release of ADH is then stopped ADH ADH ADH ADH ADH ADH

SIADH makes the production of ADH not stop by the dilution of plasma The off switch for the ADH is essentially removed, the production cannot stop Effects of SIADH ADH ADH ADH ADH ADH ADH ADH

SIADH makes the sodium in the bloodstream extremely low. This condition causes hyponatreima. Sodium levels in urine extremely high. Implications of SIADH