PNB 2265 Renal System 2
What are the sources of water gain and loss in humans? - ✔️✔️-Gain: liquids, food,
and produced metabolically
-Loss: insensible loss through skin and lungs, sweat, feces, urine
What is meant by "insensible"? - ✔️✔️Cannot be regulated or prevented
What can cause severe water loss, NaCl loss, and loss of both? - ✔️✔️-Water loss:
Vomiting and diarrhea
-NaCl loss: vomiting, diarrhea, sweating
-Both: hemorrhage
What are the sources of NaCl gain and loss in humans? - ✔️✔️-Gain: food
-Loss: sweat, feces, urine
What is the equation for normal regulation of water and salt? - ✔️✔️Nacl loss + water
loss = NaCl gain + water gain
Define diuresis and antidiuresis. - ✔️✔️-Diuresis: excreting more water in urine than
normal
-Antidiuresis: excreting less water in urine than normal to conserve it
What is the main function of ADH? - ✔️✔️Controls water reabsorption in the late distal
tubule and the collecting duct, thus controlling blood volume and blood pressure
Where is ADH produced and released? What causes its secretion? - ✔️✔️-Produced in
the supraoptic nuclei of the hypothalamus, released by the posterior pituitary. ADH is
secreted in response to increased osmolarity of the extracellular fluid (blood) that is
sensed by osmoreceptors. ADH is also secreted in response to a decrease in MAP
(because if there is a high concentration, there is a low volume)
An increase in ECF osmolarity (increases/decreases) osmoreceptor firing frequency
and speed. This, in turn, (stimulates/inhibits) ADH release from the posterior pituitary.
Give an example of when this would occur. - ✔️✔️Increases, stimulates. This would
occur if you were dehydrated, when the blood would be highly concentrated.
Once ADH enters the bloodstream and reaches its target organ, what happens? -
✔️✔️It reaches the late distal tubule and the collecting duct, and binds to it's receptors.
This creates a cAMP mechanism, which causes phosphorylation of proteins and
phosphorylation of the channel. The channel is moved and inserted into the membrane,
making the membrane permeable to water.
, When the membrane of the collecting duct becomes permeable to water, which way
does the water flow? - ✔️✔️Out of the tubule into the interstitial space to be
reabsorbed by the blood.
A decrease in ECF osmolarity (increases/decreases) osmoreceptor firing frequency and
speed. This, in turn, (stimulates/inhibits) ADH release from the posterior pituitary. Give
an example of when this would occur. - ✔️✔️Decreases, inhibits. This would occur if
you drank a lot of water, thus diluting the blood.
If ADH is not released from the posterior pituitary, the aquaporins (are/are not) inserted
into the membrane, thus the membrane is (permeable/impermeable) to water. -
✔️✔️are not, impermeable.
What is the primary active transport process in all nephron segments that is often used
to transport items such as glucose? What is this coupled to? - ✔️✔️Na reabsorption.
Coupled to water reabsorption because water follows Na (as long as the membrane is
water permeable)
Responses controlling Na excretion are initiated primarily by what two things? - ✔️✔️-
Cardiovascular baroreceptors
-Sensors in the kidney that monitor filtered load of NA (JG and macula densa cells)
What is RAAS and what is its function? - ✔️✔️The renin angiotensin aldosterone
system functions to control blood pressure (especially if there is a problem such as a
hemorrhage)
An/a (increase/decrease) in plasma volume results in _____ stimulation,
(decreased/increased) MAP, and (decreased/increased) Nacl. All of these things signal
an (increase/decrease) in renin secretion. - ✔️✔️decrease, sympathetic, decreased,
decreased, increase
Explain how the sympathetic nervous system responds to a decrease in plasma
volume. - ✔️✔️Sympathetic stimulation occurs, which increases firing of sympathetic
nerves. These nerves send signals to the JG cells to increase renin secretion.
Explain how the MAP, GFR and filtrate flow to the macula densa change when the
plasma volume decreases. - ✔️✔️The MAP decreases, which in turn decreases the
GFR. When the GFR decreases, the flow of NaCl to the macula densa cells in the DCT
decreases. The macula densa cells send a signal to the JG cells and tell them to
increase renin secretion.
If there were no problems in the body, what would happen when GFR decreases? If
there was a problem (like hemorrhaging), what would happen? - ✔️✔️-If no problem:
autoregulation would occur, the afferent arteriole would dilate, making the BP in the
kidney increase, thus increasing GFR and MAP.
What are the sources of water gain and loss in humans? - ✔️✔️-Gain: liquids, food,
and produced metabolically
-Loss: insensible loss through skin and lungs, sweat, feces, urine
What is meant by "insensible"? - ✔️✔️Cannot be regulated or prevented
What can cause severe water loss, NaCl loss, and loss of both? - ✔️✔️-Water loss:
Vomiting and diarrhea
-NaCl loss: vomiting, diarrhea, sweating
-Both: hemorrhage
What are the sources of NaCl gain and loss in humans? - ✔️✔️-Gain: food
-Loss: sweat, feces, urine
What is the equation for normal regulation of water and salt? - ✔️✔️Nacl loss + water
loss = NaCl gain + water gain
Define diuresis and antidiuresis. - ✔️✔️-Diuresis: excreting more water in urine than
normal
-Antidiuresis: excreting less water in urine than normal to conserve it
What is the main function of ADH? - ✔️✔️Controls water reabsorption in the late distal
tubule and the collecting duct, thus controlling blood volume and blood pressure
Where is ADH produced and released? What causes its secretion? - ✔️✔️-Produced in
the supraoptic nuclei of the hypothalamus, released by the posterior pituitary. ADH is
secreted in response to increased osmolarity of the extracellular fluid (blood) that is
sensed by osmoreceptors. ADH is also secreted in response to a decrease in MAP
(because if there is a high concentration, there is a low volume)
An increase in ECF osmolarity (increases/decreases) osmoreceptor firing frequency
and speed. This, in turn, (stimulates/inhibits) ADH release from the posterior pituitary.
Give an example of when this would occur. - ✔️✔️Increases, stimulates. This would
occur if you were dehydrated, when the blood would be highly concentrated.
Once ADH enters the bloodstream and reaches its target organ, what happens? -
✔️✔️It reaches the late distal tubule and the collecting duct, and binds to it's receptors.
This creates a cAMP mechanism, which causes phosphorylation of proteins and
phosphorylation of the channel. The channel is moved and inserted into the membrane,
making the membrane permeable to water.
, When the membrane of the collecting duct becomes permeable to water, which way
does the water flow? - ✔️✔️Out of the tubule into the interstitial space to be
reabsorbed by the blood.
A decrease in ECF osmolarity (increases/decreases) osmoreceptor firing frequency and
speed. This, in turn, (stimulates/inhibits) ADH release from the posterior pituitary. Give
an example of when this would occur. - ✔️✔️Decreases, inhibits. This would occur if
you drank a lot of water, thus diluting the blood.
If ADH is not released from the posterior pituitary, the aquaporins (are/are not) inserted
into the membrane, thus the membrane is (permeable/impermeable) to water. -
✔️✔️are not, impermeable.
What is the primary active transport process in all nephron segments that is often used
to transport items such as glucose? What is this coupled to? - ✔️✔️Na reabsorption.
Coupled to water reabsorption because water follows Na (as long as the membrane is
water permeable)
Responses controlling Na excretion are initiated primarily by what two things? - ✔️✔️-
Cardiovascular baroreceptors
-Sensors in the kidney that monitor filtered load of NA (JG and macula densa cells)
What is RAAS and what is its function? - ✔️✔️The renin angiotensin aldosterone
system functions to control blood pressure (especially if there is a problem such as a
hemorrhage)
An/a (increase/decrease) in plasma volume results in _____ stimulation,
(decreased/increased) MAP, and (decreased/increased) Nacl. All of these things signal
an (increase/decrease) in renin secretion. - ✔️✔️decrease, sympathetic, decreased,
decreased, increase
Explain how the sympathetic nervous system responds to a decrease in plasma
volume. - ✔️✔️Sympathetic stimulation occurs, which increases firing of sympathetic
nerves. These nerves send signals to the JG cells to increase renin secretion.
Explain how the MAP, GFR and filtrate flow to the macula densa change when the
plasma volume decreases. - ✔️✔️The MAP decreases, which in turn decreases the
GFR. When the GFR decreases, the flow of NaCl to the macula densa cells in the DCT
decreases. The macula densa cells send a signal to the JG cells and tell them to
increase renin secretion.
If there were no problems in the body, what would happen when GFR decreases? If
there was a problem (like hemorrhaging), what would happen? - ✔️✔️-If no problem:
autoregulation would occur, the afferent arteriole would dilate, making the BP in the
kidney increase, thus increasing GFR and MAP.
