renal 2 Flashcards
Osmolarity:Hypertonicity
cell
causes
shrink
insuffient water uptake
excessive water loss
Diabetes insipidus
Osmolarity:Hypertonicity
symptoms
- shrinking of neurons — confusion , irritability
- Circulatory disturbances—- low bp
- dry skin and tongue
Osmolarity:Hypotonicity
cell
causes
-swell
- Inability to excrete a dilute urine (renal failure)
- when water is rapidly ingested
Osmolarity:Hypotonicity
Symptoms and effects
- swelling of neurons - confusion …
- weakness due. to swelling of muscles cells
mainstream of reabsorption
Proximal convoluted tubule
Renin-angiotensin-aldosterone system (RAAS)
involved in
regulating Na+
RAAS
- angiotensiogen produced by liver
- low bp and high sympathetic activity stimulate renin secretion
- decreased Na stimulates renin
- Angiotensin I produced
- Angiotensin II produced
Angiotensin II:
stimulates
stimulates ADH release and thirst
when renin-angiotension-aldosterone mechanism is activated to conserve Na+
how does aldosterone work:
stimulates
stimulates opening of both sodium and potassium channels
stimulates synthesis of potassium/sodium pumps
Roles of Angiotensin II: 4 mechanisms that increase blood pressure
- systemic arterioles
- adernal cortex
- posterior pituatary
- hypothalamic neurons
systemic arterioles
↑ vasocontsriction
↑total peripheral. resistance
adrenal cortex
aldosterone secretion. ↑
na reabsorption in distal tubules and collecting ducts ↑
extracellular fluid osmolarity ↑
which then ↑ ADH secretion from the post pituitary mechanism
posterior pituitary
↑ADH secretion
↑water reaborption in distal tubules and collecting duct
↑plasma volume
hypothalamic neurons
thirst stimulation ↑
plasma volume ↑
ADH function
maintain blood pressure, blood volume and tissue water content
by controlling the amount of water and hence the concentration of urine excreted by the kidney.
