BIOL 252 Final UNC Questions with Verified
Correct Answers
Intrinsic Regulation of glomerular filtration
Autoregulation. When blood pressure is between 90-120. Myogenic stretch receptors detect
changes and afferent arteriole contracts or stretches. If blood pressure decreases, arterioles
dilate to let in more blood.
Extrinsic Regulation of glomerular filtration
Hormones, sympathetic nervous system. Occurs when blood pressure is less than 90mmHg.
norepinephrine, epinephrine via adrenal medulla. Leads to constriction of afferent arteriole
and inhibition of filtration.
Osmolality
number of solutes in 1 kg of water.
Osmolality of blood plasma
300 mosm
downward loop of Henle
permeable to H2O
upward loop of henle
permeable to ions.
What diffuses out of the loops of Henle as it goes up the loop? How does it leave?
NaCl. By way of active transport.
What carries water and NaCl away from loops of henle to bloodstream?
, vasa recta
When blood pressure is high, collecting ducts do what?
Collecting ducts become impermeable to water. Aquaporins are removed from tubule. Urine
becomes more dilute. Water is not needed in blood vessels.
What happens when osmolality is high?
Osmoreceptors in thirst center make us thirsty.
What also happens when osmolality is high? What hormone is released?
Hypothalamus releases anti-diuretic-hormone from posterior pituitary.
DCT
Distal convoluted tubule. Between loop of henle and collecting ducts.
Path of filtrate through kidneys
renal corpuscle, proximal tubule, nephron loop, distal convoluted tubule, collecting duct
How much material do the kidneys filter per day?
180 L. Only 1.5L are excreted.
What is the filtration membrane
Membrane around glomerulus that material can easily pass through. Filtration regulated by
intrinsic (auto regulation) and extrinsic (hormones, sympathetic nervous system) sources.
What happens when systemic BP is too low? Hint, it involves hormones.
Sympathetic nervous system tells adrenal medulla to release norepinephrine and epinephrine.
Afferent arterioles are constricted. Filtration inhibited.
Correct Answers
Intrinsic Regulation of glomerular filtration
Autoregulation. When blood pressure is between 90-120. Myogenic stretch receptors detect
changes and afferent arteriole contracts or stretches. If blood pressure decreases, arterioles
dilate to let in more blood.
Extrinsic Regulation of glomerular filtration
Hormones, sympathetic nervous system. Occurs when blood pressure is less than 90mmHg.
norepinephrine, epinephrine via adrenal medulla. Leads to constriction of afferent arteriole
and inhibition of filtration.
Osmolality
number of solutes in 1 kg of water.
Osmolality of blood plasma
300 mosm
downward loop of Henle
permeable to H2O
upward loop of henle
permeable to ions.
What diffuses out of the loops of Henle as it goes up the loop? How does it leave?
NaCl. By way of active transport.
What carries water and NaCl away from loops of henle to bloodstream?
, vasa recta
When blood pressure is high, collecting ducts do what?
Collecting ducts become impermeable to water. Aquaporins are removed from tubule. Urine
becomes more dilute. Water is not needed in blood vessels.
What happens when osmolality is high?
Osmoreceptors in thirst center make us thirsty.
What also happens when osmolality is high? What hormone is released?
Hypothalamus releases anti-diuretic-hormone from posterior pituitary.
DCT
Distal convoluted tubule. Between loop of henle and collecting ducts.
Path of filtrate through kidneys
renal corpuscle, proximal tubule, nephron loop, distal convoluted tubule, collecting duct
How much material do the kidneys filter per day?
180 L. Only 1.5L are excreted.
What is the filtration membrane
Membrane around glomerulus that material can easily pass through. Filtration regulated by
intrinsic (auto regulation) and extrinsic (hormones, sympathetic nervous system) sources.
What happens when systemic BP is too low? Hint, it involves hormones.
Sympathetic nervous system tells adrenal medulla to release norepinephrine and epinephrine.
Afferent arterioles are constricted. Filtration inhibited.
