7.1 Regulation of body water, Na and K

Question 1

how is anti diuretic hormone synthesised?

Answer 1

Synthesied in the paraventricular/supraoptic nuclei due to input from the osmoreceptors and vasomotor sensor in the medulaa oblongata via baroreceptors

Question 2

Where is ADH secreted from?

Answer 2

POSTERIOR pituitary

Question 3

what stimulates ADH release?

Answer 3

small increases in osmolarity

BP increase

Question 4

What receptors does ADH work at and what is the outcome?

Answer 4

G protein coupled receptors: V1 and V2
V1: vasoconstriction via Gq and IP3 production
V2: antidiuretic action in DT and CT via Gs and PKA activation

Question 5

What effects does ADH have in the DT and CT?

Answer 5

inserts the aquaporins stored in vesicles under the apical membrane, also increases urea diffusion via UT1 and UT4

Question 6

what is the main driver for thirst?

Answer 6

change in osmolarity

Question 7

what is effective circulating volume?

Answer 7

the portion of the ECF contained within the vascular system and effectively perfusing tissues

Question 8

What determines effective circulating volume?

Answer 8

Na balance