7.2 Physiology of the Urinary System Part 3 Flashcards
What does the release of renin cause?
constriction of the afferent and efferent arterioles
converts angiotensinogen to angiotensin I
Where is angiotensin I converted to angiotensin II?
lungs
What is the function of angiotensin II?
- thirst mechanism for the hypothalamus to cause a person to feel thirsty
- vasoconstriction
- causes the adrenal cortex to release aldosterone
What does drinking water help with?
increases blood volume thereby increasing blood pressure
What is the function of aldosterone?
causes renal tubules to reabsorb more sodium increasing water retention
What is tubular reabsorption?
process of fluid and substances moving from filtrate back into the blood
What regulates tubular reabsorption?
hormones
What is diffusion?
passive process that does not require energy
How can tubular reabsorption occur?
active or passive
Where does the greatest amount of renal tubular reabsorption occur?
cells of the PCT
What is reabsorbed in the PCT?
glucose
amino acids
water
ions
In the loop of Henle which limbs can water leave?
leave descending limb not ascending limb
In the loop of Henle which limbs can Na and K leave?
leave the ascending limb but not the descending
How much Na and Cl and water remain in the filtrate after the PCT and loop of Henle?
10% of the ions and 20% of the water
What conditions can be controlled through ion channels in the DCT and collecting ducts?
abnormal blood pressure
low blood volume
low sodium concentration
high K concentration
