F21-1

F21-2

F21-3

Anti Diuretic Hormone (ADH) Renin-Angiotensin-Aldosterone Atrial Natriuretic Hormone

(ANH) Urodilatin

↓urine volume

ADH

OR

OR

OR

OR

BR

BROR

ADH SECRETION

F 21-4

F21-5

F12-6

F12-7

Age Intracell Extracell Total

Young 45 30 75

Adult 40 20 60

F21-8

F21-9

Sources Drinking Food Cellular metabolism

Losses Urine Evaporation

Sweating Respiration and tongue

Faeces

F21-10

Water in oral mucosa

Mechanical distension of the stomach

F21-11

Passage of ions is regulated Plasma membrane Active transport Electric charge

Water move by osmosis

F21-12

Detected by hypothalamic osmoreceptors

Increase in thirst sensation

Increase ADH secretion Increase fluid intake Increase permeability of

renal cells More water move into

blood Decrease blood osmolality

LOW OSMOLALITY Detected by hypothalamic

osmoreceptors Decrease thirst sensation Decrease ADH secretion Decrease fluid intake Decrease permeability of

renal cells Less water move into

blood Increase osmolality

HIGH OSMOLALITY

F21-13

Increased BP in right atriumANH

Increased Na+

and water excretionreduce BP

Increased ANH incirculation

F21-14