Osmoregulation Flashcards
Where is ADH produced?
The hypothalamus
How is ADH stored?
Carried via axonal transport to he posterior pituitary for storage
How is ADH secreted?
From the pituitary into the blood when instructed by the hypothalamus
What are osmorecepetors?
They detect water levels
Where are osmoreceptors found?
Posterior hippocampus
What does high osmolarity mean?
Too many solutes in the blood
What does low stretch in arteries mean?
blood volume is low
How does the hypothalamus monitor blood concentration?
Using osmoreceptors
What happens when blood concentration is higher than homeostatic norms?
ADH is released by posterior pituitary glands
What does ADH do?
It acts as a 2nd messenger cascade which produces cAMP
What does ADH cause?
More water channels are inserted into the distil convoluted tubules and collecting duct membranes
What happens if ADH is present?
Fluid in the DCT and CD equilibrates with tissue so water is drawn out by osmosis
What is the result of ADH being present?
More concentrated urine is produced
What controls ADH levels?
A negative feedback loop
What initiates ADH releases?
The hypothalamic thirst centre
Where
Where is aldosterone produced?
In the adrenal cortex
What does aldosterone cause?
Increased K+ excretion and Na+ retention in the kidney
What is the result of aldosterone?
Extracellular tissue fluid becomes more concentrated than body cell fluid
What happens when extracellular tissue fluid becomes more concentrated?
blood water potential draws water out of cells and restores blood volume
