7.2 Physiology of the Urinary System Part 5 Flashcards
Where is ADH stored and released?
posterior pituitary
What is the function of ADH?
inhibits urine output by increasing the number of channels in the cells of the collecting ducts
What does increasing the number of channels in the collecting ducts by ADH cause?
water to pass easily from the filtrate and move into the surrounding interstitial space and returning to blood circulation
What is the release of ADH connected to?
degree of body hydration
What are factors that cause dehydration?
excessive water loss
sweating
vomitting
diarrhea
hemorrhage
What secretes aldosterone?
adrenal cortex
What is the function of aldosterone in the collecting ducts?
places several types of ion channels inside of the cells of the collecting ducts
How does aldosterone increase sodium reabsorption?
placing sodium-hydrogen ion channels in the collecting ducts
How does aldosterone increase potassium secretion?
sodium-potassium pump
What is the overall result of aldosterone?
increase blood volume and blood pressure
When can aldosterone release occur?
RAA system
in response to high K levels or low Na levels in the extracellular compartment
What are the normal triggers for the RAA system?
CNS
decreased renal filtrate
decreased osmotic pressure
decrease blood pressure
How quick is the aldosterone control system?
slow; several hours to several days
What are diuretics?
substances that act on the nephron to increase urinary output
What do most diuretic drugs do?
increase sodium reabsorption therefore less water is reabsorbed from the filtrate
