lecture 27: renal physiology 3

Question 1

antidiuretic hormone triggers

Answer 1

• ADP made in hypothalamus and stored in posterior pituitary vesicles (technically AVP). th
• osmoreceptors in hypothalamus sence increase NA conc. and increase osmolarity
• signal sent to pituitary to release ADH
• also blood pressure/volume can increase ADH release (baroreceptors)

Question 2

antidiuretic hormone actions

Answer 2

• acts on convoulted distal tubule and collecting duct
• stimulates vesicles with aquaporin-2 channels that bring water into cell, to insiert into apical membrane
• water travels through basolateral membrane into blood

Question 3

osmoreceptors

Answer 3

• stretch activated cation channels
• hypertonic draws water out and cel shrinks
• channels activated and NA+ enters causing action potential

Question 4

renin angiotensin aldosterone triggers

Answer 4

• macula densa cells in distal tubule sense low sodium causing release of renin
• increase sympathetis activity triggers release

Question 5

renin angiotensin aldosterone actions

Answer 5

regulate salt balance by:
- renin binds with angiotensinogen to for angiotensin I then II with ACE.
- angiotensin II causes vasoconstriction and aldosterone release
- Na+ retention

Question 6

response to Nacl (salt) ingestion

Answer 6

will draw water out of cells
- plasma/ECF volume increases, intracellular decreases

Question 7

response to water ingestion

Answer 7

• rapidly equilibriates through inter and extra cellular fluid
• decrease osmolarity

Question 8

response to salt AND water ingestion

Answer 8

will remain in ECF, no effect on plasam osmolarity

Question 9

atrial natriuretic peptide

Answer 9

• released in response to stretch of the atria (increase blood volume)
• reduces renin, adh, aldosterone release, increase GFR
• reduces Na and water reabsorption