Renal Stuff Flashcards
The movement of particles from blood vessels to nephron is …
secretion
The movement of particles from the nephron to the blood vessel is …
absorption
This occurs at the glomerular capsule and glomerulus capillaries …
filtration
What is secreted passively out of the PCT into the peritubular capillary?
Water (H20), K+, HCO3-
What is secreted actively out of the PCT into the peritubular capillary?
NaCl, glucose
What is secreted passively out of the peritubular capillary into the PCT?
NH3
What is secreted actively out of the peritubular capillary into the PCT?
H+
Where do most of the water (H2O) and Na+ reabsorption occur?
Proximal Convoluted Tubule
What occurs near the lumen (apical surface) of the PCT?
(during reabsorption)
Na+/Glucose symporter
What occurs near the basal surface of the PCT?
(during reabsorption)
Na+/K+ pump
glucose exits via facilitated diffusion
Thus, Na+ enters the blood vessel, K+ exits the blood vessel and glucose enters the blood vessel
Know the countercurrent multiplier system.
but really dam good
(know it)
Know the countercurrent exchange system
(know it)
Which of the following is not true about Urea?
a) It is produced in the liver
b) It is released into the blood
c) It is highly toxic and highly reactive
d) It is water-soluble
c) it is highly toxic and reactive,
Urea is actually non-toxic and low reactive. NH3, the nitrogenous waste that is turned into urea is highly reactive and toxic.
How is urea made?
NH3 is converted into urea in the liver by the urea cycle.
Which is correct about the goal of the urinary system?
a) to dilute urine and maximize H2O loss
b) to concentrate filtrate and minimize H2O gain
c) to concentrate urine and minimize H2O loss
d) None of the above
c) to concentrate urine and minimize H2O loss
What happens under diuretic conditions?
increase urine volume/output;
increase H2O in renal tubules
decrease H2O in blood vessels
thus, decrease blood pressure
What happens under antidiuretic conditions?
decrease urine volume/ output.
decrease H2O in renal tubules
increase H2O in blood vessels
thus, increase blood pressure
What effect does ADH have?
ADH increases the number of urea transporters;
leading to more urea coming out and making the medulla more hypertonic;
H2O leaving the nephron (from the collecting duct; descending loop of henle, and descending vasa recta);
water enters the blood vessel (ascending vasa recta);
water reabsorption (increase blood pressure)
Describe volume regulation for concentrated urine. What is the stimulus?
Stimulus:
1. Low water intake (dehydration)
2. High salt intake
- increases concentration in blood
- signals the hypothalamus
- signals the posterior pituitary
- increase ADH
- signals the kidneys
- increase water reabsorption in blood vessel
(blood volume increases & BP increases) - less water in the urine, (concentrated urine)
Describe volume regulation for diluted urine. What is the stimulus?
Stimulus:
1. Low salt intake
2. High water intake (overhydration)
- decrease concentration in blood (dilute blood)
- signals the hypothalamus
- decreases ADH
- signals the kidneys
- decreases water reabsorption in blood vessel (blood volume decreases & BP decreases)
- more water in the urine, (diluted urine)
How does ADH affect AQP and Urea transporters?
ADH is known as Vasopressin. The posterior pituitary secretes it in response to dehydration.
ADH increases the number of urea transporters at the collecting duct;
it increases the number of AQP (water channels);
This allows for more urea to enter the medulla;
creates a hypertonic environment;
because of the hypertonic environment, water leaves the CD, desc LH, and Desc VR;
all the water enters the asc. VR;
water reabsorption, diluting blood, increasing BP
what is the macula densa?
they detect blood volume changes, are activated by low blood volume, and are part of the thick ascending loop of henle.
what are granular cells?
release enzyme called renin and are part of the afferent arteriole.
Describe the RAA system
Macula densa cells detect low blood volume;
granular cells are activated and release the enzyme renin (made by the liver);
Renin catalyzes the reaction from angiotensinogen (made by the liver) to angiotensin 1 (A.T.1);
Angiotensin becomes Angiotensin 2 with the help of the enzyme, A.C.E;
Angiotensin 2 activates the adrenal cortex;
adrenal cortex releases aldosterone;
Increase Na+ (salt) reabsorption;
increase water reabsorption;
increase blood volume;
increase blood pressure.
what happens to the RAA system if Angiotensin 2 is inhibited?
Building/ Increase of Angiotensin 1 and Renin;
Blood volume decreases/ Blood pressure decreases.
