Homeostasis

Question 1

explain and describe the mechanism of ADH mechanism

Answer 1

• ADH is released and secreted from the posterior pituitary gland
• it is carried in the blood and to the cells of the collecting duct.
• it binds to the receptors on the cell-surface membrane
• a seconds messenger is triggered and formation of cyclic AMP (cAMP)
• cAMP is a molecule which relays the signal received at cell surface receptors
• the cAMP causes the vesicles lining the collecting duct to fuse with the cell surface membrane
• the membrane of these vesicles contain protein based water channels which make the membrane permeable to water
• this provides a route for water to move out the tubule by osmosis

Question 2

what is the structure of the nephron in order

Answer 2

• bowmans capsule
• proximal convoluted tubule
• loop of henle
• distal proximal convoluted tubule
• collecting duct

Question 3

describe and explain what happens in the bowmans capsule?

Answer 3

• cup shaped structure which contains the glomerulus