Test 4 review sheet Flashcards
difference betwen a cortical nephron and juxtamedullary nephron
cortical has shorter loop of henley. Juxtamedullary has a longer one which allows for more production of concentrated urine.
What makes up the filtration membrane
- simple squamous epithelial cells of the capillaries of the glomerulus 2. basement membrane 3. podocytes
Which pressure forces fluid out of the glomerulus
hydrostatic pressure
which pressure forces fluid IN the glomerulus
blood colloidal osmotic pressure AND the hydrostatic pressure in the capsular space
what is a counter current?
fluid moving in parallel tubes in opposite direction with exchange between the tubes
where would you find a counter current?
Loop of henley and vasa recta
why is loop of henley called a counter current multiplier?
Because it uses active transport to reabsorb sodium and chloride
What would happen if you constrict the afferent artery into the glomerulus?
Less blood flow, less pressure and less GFR
What would happen if you dilate the afferent artery into the glomerulus?
More blood flow, increase blood pressure and more GFR
What would happen if you constrict the efferent artery into the glomerulus?
Higher blood pressure and higher GFR because the blood back up.
What would happen if you dilate the efferent artery into the glomerulus?
less blood pressure and less GFR because the blood can pass more easily.
There is a direct relationship between blood hydrostatic pressure and
GFR - Glomerular filtration rate
If you increase blood pressure you will increase
GFR
If you increase blood pressure you will increase _________ and make more ________
GFR, Filtrate
Which arteriole has a larger lumen?
afferent.
Why does efferent artery have a smaller lumen?
to keep blood pressure in the glomerulus high so more GFR can occur
Why does blood pressure in the glomerulus need to be high
so more GFR and more filtrate can happen
What binds to water channels that line the distal convoluted tubule and the collecting duct and will increase the number of open water channels
ADH - antidiarretic hormone
increased water channels will do what?
increase water reabsorption back into the blood
what will increase open water channels, decrease the osmolarity, increase blood volume and allow you to make small amounts of concentrated urine?
ADH
ADH and Aldosterone will both cause the body to make
small volumes of concentrated urine because you reabsorbed the salt so you make less sodium.
ADH is secreted from the
posterior pituitary gland
They hypothalamus causes the posterior pituitary gland to increase the release of
ADH
ADH will be released when there is ______ ________ in the extracellular fluid
high osmolarity
ADH is a _______ that works fast
protein
Secretion of ADH is controlled by what two types of receptors?
osmoreceptors and baroreceptors
aldosterone is secreted from the
adrenal cortex
aldosterone is secreted when
there is low extracellular sodium and high extracellular potassium.
Aldosterone travels to the kidneys it is a
steroid hormone or lipid
what does adlosterone do
increases the number sodium or chloride transport proteins.
normally there is high _____ inside the cell and high________ outside the cell
potassium, sodium
What causes more water reabsorption back into the blood when osmolarity is sensed by the hypothalumus?
ADH
Why will ADH cause you to make small volumes of urine?
because ADH promotes reabsorption of water back into the blood.
Aldosterone is secreted from the adrenal cortex in response to
low extracellular sodium and high extracellular potassium
Aldosterone travels to the kidneys to increase the number of
sodium and chloride transport proteins
aldosterone will help increase the absorption of what?
sodium and chloride which will bring more water. water follows sodium. Blood volume will increase
To remove the excess potassium in the extracellular fluid, aldosterone will
secrete it right into the urine bypasses filtration.
aldosterone and ADH will both cause the body to produce
small volumes of concentrated urine because you have reabsorbed the salt and water so you make less sodium.
When would there typically be low extracellular sodium
trauma or injury to the cells
low blood flow and low blood pressure will trigger the glumerular cells to secrete _____
renin.
What will change angiotensinogen to angiotensin 1?
Renin
Are angiotensinogen and angiotensin 1 active or inactive?
inactive
How does angiotensin 1 make angiotensin 2
travels to the lungs where it is cut into angio2 by ACE.
is angiotensin 2 active or inactive?
active
angiotensin 2 is a potent
vasoconstrictor
angiotensin 2 will increase _____ which will increase _______which will increase _______ and increase _________ and make__________
blood pressure, aldosterone production, sodium and chloride reabsoption, blood volume, small amounts of urine.
low blood pressure and low blood volume will also stimulate sympathetic nervous system which will increase
vasocontriction.
What will not happen during sympathetic stimulation
urine production because you need to reabsorb the water to increase your blood volume
renin leads to what very important thing from the lungs?
angiotensin 2
angiotensin 2 will increase aldosterone production
true
aldosterone will increase
sodium and chloride reabsorption, water follows and increase blood volume and you will make small volumes of concentrated urine. these things will raise the blood pressure and blood volume
to raise the blood pressure and blood volume you need
aldosterone.
if your arm is in a chipper will you make urine?
NO
What happens when you exceed the tubular maximum?
The excess appears in your urine
control of micturition
stretch of the bladder. For control there are both internal and external urethral sphincters
internal urethral sphincter is
smooth muschle and involuntarily controled
external urethral sphincter is
skeletal muscle and voluntary controle.
both urethral sphincters need to ______ inorder to void bladder
relax
kidneys are retroperitoneal which means they are
out of the peritoneal cavity along the body wall.
blood pressure is higher in the ____, why?
glomerulus because of the anatomy of the smaller efferent artery.
between the glomerulus, the vasa recta, the efferent, afferent and peritubular capillaries, which has the highest blood pressure?
glomerulus. Because of the anatomy.
what happens in the glomerulus
filtration
what happens in the proximal convoluted tubule?
reabsorption of everything.
what happens in the descending loop of Henley?
reabsorption of mostly water
what happens in the ascending loop of henley
reabsorption of sodium and chloride - NEVER WATER!
What happens in the distal convoluted tubule and collecting duct
additional reabsorption of sodium chloride and water under hormonal control!
What is the effect on reabsorption at the proximal convoluted tubule when ADH is present?
No effect. ADH only effect the distal convoluted tubule.
What is the effect on water reabsorption at the distal convoluted tubule when ADH is present?
Water reabsorption will go up.
Hormones only work in the
last part of the nephron
blood osmolarity
= 300
filtrate osmolarity
300
in the proximal convoluted tubule the osmolarity remains
300
the descending limb of the loop of henly reabsorps water so when it gets to the tip the osmolarity is
highest it will ever be - 1200
the osmolarity towards the distal convoluted tubule is the
lowest it will ever be
100 because the ascending limb reabsorbs sodium and chloride
if no hormones were present and you were to void when the fluid is around the DCT you have have
large volumes of dilute urine
more hormone gives you more
effect
if you have ADH and Aldosterone present you will increase
water and salt reabsorption so your osmolarity can be as high as 1200.
what substances shouldn’t be in your urine
RBC, WBC and large proteins and glucose
why should there be no RBC, WBC or large proteins in your urine?
too large to fit across the filtration membrane
why should you not have glucose?
because all of your glucose should be reabsorbed.
things that are in your urine?
water with lots of small things, electrolytes along with waste products like urea
blood pressure is directly related to
GFR
the glomerulus has the highest blood pressure in the nephron
true
when you have an increase in hormones, overall you will have less urine and more
water reabsorption back into the blood.
what is the major hormone that regulates potassium
aldosterone!
what is the difference between extracellular and intracellular fluid?
extracellular has more sodium, intracellular has more potassium.
sensible perspiration
sweat
insensible perspiration
water loss from lungs and skin that you don’t feel or sense.
PH is the measure of
concentration of free hydrogen ions on a scale 0-14
As you increase free hydrogen you
lower the PH
what is a neutral PH
7
less than 7 on the PH scale is
acidic
greater than 7 on the PH scale is
basic
An acid will increase concentration of
free hydrogen
base will decrease the concentration of
free hydrogen.
buffer system is
a weak acid and a weak base working together
What is acidosis?
PH is less than 7.35
What is alkalosis
PH is greater than 7.45
In metabolic acidosis you have a
low PH and lots of free hydrogen
in metabolic alkalosis you have a
high PH and low free hydrogen
how do you fix metabolic acidosis and alkalosis?
chemical buffer systems
what does the respiratory system do about metabolic acidosis
increase in respiratory rate to have less Co2, less free hydrogen and PH goes up
what does the respiratory system do about metabolic alkalosis
decreased respiratory rate which raises co2 and free hydrogen and will lower the PH
what does the urinary system do about metabolic acidosis
increase hydrogen secretion into the urine, increase bicarbonate reabsorption back into the blood
what does the urinary system do about metabolic alkalosis
increase hydrogen reabsorption and increase bicarbonate secretion.
If you have metabolic acidosis or alkalosis you can have any buffer system working (resp, urinary) BUT if the problem is in the lungs only the urinary buffer system will be able to help
TRUE
3 major buffer systems in the urine
bicarbonate, phosphate and ammonia
if you have hypo ventilation or low respiratory rate you have
have a low respiratory rate you have more Co2, more free hydrogen and a lower PH
If you have Hyperventilation
respiration rate goes up you have less co2, less free hydrogen and PH goes up.
