A&P 2 Module 7. 2024 Edition. Real
Questions & Answers. Graded A+
________are found in the cortex region of the kidney, except for a portion of their loop
of Henle which extends into the medulla. ______pass deeply into the medulla because
of their location and their longer loops of Henle. - ANSCortical nephrons; juxtamedullary
nephrons
______are sphincters located where the ureters enter the bladder. - ANSUreterovesical
valves
A vertical cross section shows what three regions inside the kidney? - ANSthe cortex,
the medulla, and the pelvis
About how many gallons are filtered vs. excreted as urine? - ANSAbout 47 gallons of
glomerular filtrate containing the water, nutrients, and essential ions are removed daily
from the blood plasma. By the time filtrate enters the collecting ducts, it contains about
only 0.5 gallons of urine, with the other 99% being returned to the blood.
About what percentage of Na+ is reabsorbed in the PCT? The loop of Henle? The
DCT? - ANS65%; 25%; 10% (DCT reclaims nearly all when necessary)
ADH is secreted by the ____. - ANSposterior pituitary
Angiotensinogen is a pre-enzyme produced by the ___ and freely circulates in the
blood. - ANSliver
Both ureters open into the bladder via the _____. - ANSureteral orifices
Calculate the net filtration pressure for a patient with a blood hydrostatic pressure of
60mmHg, a colloid osmotic pressure of 32mmHg, and a capsular pressure of 18mmHg.
- ANSNet filtration pressure = (Outgoing forces - incoming forces)
= HP- (COP + Capsular pressure)
=60mmHg - (32mmHg +18mmHg))
= 10 mmHg (net outward pressure)
Describe normal urine. - ANSNormal excreted urine is usually clear and pale to deep
yellow in color depending on the body's degree of hydration. The normal range of urine
pH is 4.5 to 8.0. Urine contains about 95% water with about 5% of solutes of varying
amounts.
Describe the action of ADH. - ANSADH inhibits urine output by increasing the number of
channels in the cells of the collecting ducts. Increasing the channels allows water to
pass easily from the filtrate and move into the surrounding interstitial space, eventually
, returning to blood circulation. Water rapidly leaves the filtrate through the channels in
the collecting ducts opened by ADH. ADH retains up to 99% of the water in filtrate, and
the kidneys excrete a very small volume of highly concentrated urine.
Describe the bladder when it is full and when it is empty. - ANSThe bladder is very
elastic, collapsing into it a pyramidal shape when empty. As it is filled by urine, the
bladder swells and becomes pear-shaped, rising in the abdominal cavity.
Describe the distal convoluted tubule. - ANSThe last part of the tubule is the highly
coiled distal convoluted tubule which allows for hormonally controlled reabsorption of
water and solutes. Mostly the distal convoluted tubule is responsible for the secretion of
unwanted substances.
Describe the impact of weak acids on a solution. - ANSWeak acids do not significantly
contribute to the pH of a solution because in this form, H+ is tightly bound and cannot
dissociate to become free H+.
Describe the loop of Henle. - ANSThe second section is the hairpin loop of Henle.
Initially the loop of Henle has the descending limb followed by the ascending limb. The
descending limb allows water loss and the ascending limb allows salt (NaCl) loss.
Describe the mechanisms of aldosterone. - ANSAldosterone increases Na+
reabsorption through the excretion of hydrogen ions (H+). Sodium ions are pumped out
of the filtrate while hydrogen ions are pumped inside for excretion. Because water
follows salt, Na+ reabsorption also causes water reabsorption. A second action of
aldosterone is to increase potassium secretion through sodium-potassium pumps. Na+
is pumped out of the filtrate to be returned to the blood while potassium (K+) is excreted
in urine.
Describe the nervous system control of the renal flow. - ANSWhen the nervous system
takes over regulation, the afferent arterioles diameter is narrowed by sympathetic nerve
fibers. The release of the hormone epinephrine by the adrenal medulla causes a
decrease in renal blood flow and decreases the GFR.
Describe the process of micturition. - ANSMicturition is the act of emptying the bladder.
As urine accumulates, the rugae flatten and the wall of the bladder thins as it stretches,
allowing the bladder to store larger amounts of urine without a significant rise in internal
pressure. The urge to urinate usually starts when about 200 ml of urine has
accumulated, causing distension of the bladder walls which initiates a visceral reflex
arc. This causes the detrusor muscle to contract and the internal sphincter to relax
forcing stored urine through the internal sphincter into the upper part of the urethra. A
person can consciously resist this initial urge to urinate because the external sphincter
is voluntarily controlled. As the bladder continues to fill, the desire to urinate becomes
stronger. Eventually, if the amount of urine reaches 100% of the bladder's capacity, the
voluntary sphincter opens, and micturition occurs involuntarily.
Questions & Answers. Graded A+
________are found in the cortex region of the kidney, except for a portion of their loop
of Henle which extends into the medulla. ______pass deeply into the medulla because
of their location and their longer loops of Henle. - ANSCortical nephrons; juxtamedullary
nephrons
______are sphincters located where the ureters enter the bladder. - ANSUreterovesical
valves
A vertical cross section shows what three regions inside the kidney? - ANSthe cortex,
the medulla, and the pelvis
About how many gallons are filtered vs. excreted as urine? - ANSAbout 47 gallons of
glomerular filtrate containing the water, nutrients, and essential ions are removed daily
from the blood plasma. By the time filtrate enters the collecting ducts, it contains about
only 0.5 gallons of urine, with the other 99% being returned to the blood.
About what percentage of Na+ is reabsorbed in the PCT? The loop of Henle? The
DCT? - ANS65%; 25%; 10% (DCT reclaims nearly all when necessary)
ADH is secreted by the ____. - ANSposterior pituitary
Angiotensinogen is a pre-enzyme produced by the ___ and freely circulates in the
blood. - ANSliver
Both ureters open into the bladder via the _____. - ANSureteral orifices
Calculate the net filtration pressure for a patient with a blood hydrostatic pressure of
60mmHg, a colloid osmotic pressure of 32mmHg, and a capsular pressure of 18mmHg.
- ANSNet filtration pressure = (Outgoing forces - incoming forces)
= HP- (COP + Capsular pressure)
=60mmHg - (32mmHg +18mmHg))
= 10 mmHg (net outward pressure)
Describe normal urine. - ANSNormal excreted urine is usually clear and pale to deep
yellow in color depending on the body's degree of hydration. The normal range of urine
pH is 4.5 to 8.0. Urine contains about 95% water with about 5% of solutes of varying
amounts.
Describe the action of ADH. - ANSADH inhibits urine output by increasing the number of
channels in the cells of the collecting ducts. Increasing the channels allows water to
pass easily from the filtrate and move into the surrounding interstitial space, eventually
, returning to blood circulation. Water rapidly leaves the filtrate through the channels in
the collecting ducts opened by ADH. ADH retains up to 99% of the water in filtrate, and
the kidneys excrete a very small volume of highly concentrated urine.
Describe the bladder when it is full and when it is empty. - ANSThe bladder is very
elastic, collapsing into it a pyramidal shape when empty. As it is filled by urine, the
bladder swells and becomes pear-shaped, rising in the abdominal cavity.
Describe the distal convoluted tubule. - ANSThe last part of the tubule is the highly
coiled distal convoluted tubule which allows for hormonally controlled reabsorption of
water and solutes. Mostly the distal convoluted tubule is responsible for the secretion of
unwanted substances.
Describe the impact of weak acids on a solution. - ANSWeak acids do not significantly
contribute to the pH of a solution because in this form, H+ is tightly bound and cannot
dissociate to become free H+.
Describe the loop of Henle. - ANSThe second section is the hairpin loop of Henle.
Initially the loop of Henle has the descending limb followed by the ascending limb. The
descending limb allows water loss and the ascending limb allows salt (NaCl) loss.
Describe the mechanisms of aldosterone. - ANSAldosterone increases Na+
reabsorption through the excretion of hydrogen ions (H+). Sodium ions are pumped out
of the filtrate while hydrogen ions are pumped inside for excretion. Because water
follows salt, Na+ reabsorption also causes water reabsorption. A second action of
aldosterone is to increase potassium secretion through sodium-potassium pumps. Na+
is pumped out of the filtrate to be returned to the blood while potassium (K+) is excreted
in urine.
Describe the nervous system control of the renal flow. - ANSWhen the nervous system
takes over regulation, the afferent arterioles diameter is narrowed by sympathetic nerve
fibers. The release of the hormone epinephrine by the adrenal medulla causes a
decrease in renal blood flow and decreases the GFR.
Describe the process of micturition. - ANSMicturition is the act of emptying the bladder.
As urine accumulates, the rugae flatten and the wall of the bladder thins as it stretches,
allowing the bladder to store larger amounts of urine without a significant rise in internal
pressure. The urge to urinate usually starts when about 200 ml of urine has
accumulated, causing distension of the bladder walls which initiates a visceral reflex
arc. This causes the detrusor muscle to contract and the internal sphincter to relax
forcing stored urine through the internal sphincter into the upper part of the urethra. A
person can consciously resist this initial urge to urinate because the external sphincter
is voluntarily controlled. As the bladder continues to fill, the desire to urinate becomes
stronger. Eventually, if the amount of urine reaches 100% of the bladder's capacity, the
voluntary sphincter opens, and micturition occurs involuntarily.
