Biochemistry Flashcards
What is the main hormone which controls water?
ADH
Where is ADH released?
Posterior Pituitary
How does ADH balance water in the body?
It causes water to be reabsorbed from the renal tubules.
- Increase in ADH causes a small volume of Concentrated urine.
- Decrease in ADH causes a large volume of Dilute urine.
What is urine concentration/dilution measured in?
Urine Osmolality
What mechanism causes water reabsorption from the Renal Tubules?
Countercurrent Multiplication.
How is Sodium Balances in the body?
Controlled by Steroids from the adrenals.
Known as Mineralocorticoids.
- E.g. Aldosterone (main one)
- Also Cortisol
What happens with an Increase in Mineralocorticoid activity?
Sodium gain.
In what compartments is water found / able to go to?
Water is present in/can move between all body compartments.
Loss / Gain of water is from / to the whole body.
What compartments is sodium found / able to go to?
Sodium is confined to the extracellular fluid (ECF). There’s a pump in the plasma membrane that keeps it there.
SO sodium loss of gain is solely from / to the ECF.
Why are Sodium and Water associated with eachother?
Water Follows solute by osmosis. Na+ is greater than anything else, Hence water follows sodium.
So if you lose / Gain Na+ from the ECF - you lose / gain water with it.
What would a Low Sodium but normal IL H2O result in?
Hyponutreamia.
What would a normal sodium and low IL H2O result in?
Hyponutraemia.
What would a high sodium and normal IL H20 result in?
Hypernutraemia
What would a normal Sodium and Low IL H20 result in?
Hypernutraemia
What are some clinical signs of a Hyponutraemia?
- Dry mucous membranes
- Decreased Skin Turgor
- Decreased urine output
- Postural hypotension.
- Increased Pulse rate
- Decreased Consiousness.
