What is the structure called AKA. Countercurrent Multiplier?
Nephron loop
100
What is the goal of the secretion of Angiotensin II?
Increase BP/BV
100
What are 4 properties of urine?
Colorless-yellow-amber; distinct odor as made by urea; specific gravity of 1.00-1.03; osmolarity usually 500-800 mOsm/L; pH of 4.5-8.2; should not have protein, glucose, RBCs, WBCs, kidney cells; secrete ~1-2 L/day
100
What is the function of the detrusor muscle?
Squeeze bladder during micturition
200
What is tubular secretion?
Removes additional wastes from the blood and adds them to the tubules/filtrate.
200
Osmolarity ________ as the filtrate goes throughout the descending limb. Osmolarity _________ as the filtrate moves throughout the ascending limb. Osmolarity ________ as the filtrate moves through the collecting duct.
What two substances are reabsorbed last in the collecting duct (before the urine is excreted)?
H20, Urea
300
The nephron loop and ____________ work together to maintain the countercurrent multiplier and _________.
Blood vessels; gradient
300
To save blood volume, your body will secrete ______. This will cause increased ____ reabsorption.
ADH; H2O
300
Figure this: You are measuring the patient's inulin. A patient has urine concentration of 33 mg/ml, a plasma concentration of 0.4 mg/ml and a calculated rate of 3 mL/min of urine. What is the patient's GFR? Is this normal?
247.5 mL/min; No, the normal GFR is ~125 mL/min
300
What is the function of the PSNS during micturition? Of the SNS?
PSNS: causes involuntary contraction of detrusor muscle and further stretching of fibers to make you have to pee.
SNS: relaxes internal sphincter (involuntary) and relaxes external sphincter (voluntary) so you can pee.
400
If you have a decrease in blood pressure and Na+ reabsorption, what secretion will be made? What will it do?
Aldosterone; will cause Na+ reabsorption to go up, so you will therefore retain Na+
400
What does the countercurrent multiplier do?
Maintain/create osmotic gradient
400
Atrial Natriuretic Peptide is secreted in times where the blood volume is ____. This causes four things to happen: 1., 2., 3., 4.
Increased.
1. Decreased ADH, causing increased H20 excretion
2. Increased GFR by dialating AA, constricting EA
3. Decreased aldosterone to cause increased Na+ excretion
4. Decreased Na+ reabsorption in the CD
400
If RPC is greater than GFR, the substance is _____. If RPC is less than GFR, the substance is _____.
Secreted; reabsorbed
400
What structures are contracted during filling?
Sphincters
500
What is tubular reabsorption?
Returning water/solutes to the blood from the tubular fluid.
500
Sodium leaves via:
and H2O leaves via:
Active transport; Diffusion
500
What happens when someone is overhydrated? Include the hormones released, and signals made by the brain to correct this.
Excess H2O is sensed when the plasma osmolarity goes down. Decreased firing of the osmoreceptors in the hypothalamus will cause a decreased release of ADH (makes you NOT pee). This causes decreased amount of aquaporins opened in the CD and thus decreased H2O reabsorption by the body. This will increase urine output and thus increase osmolarity in the plasma (it is not being diluted by the H2O).
500
Explain what happens during the micturition reflex:
1. Stretch receptors in the bladder send message
2. to the spinal cord. Spinal cord responds by activating PSNS
3. PSNS causes contraction of detrusor muscle and stretch receptors stretch more.
4. Spinal cord inhibits SNS, causing relaxation of internal (and external) urethral sphincters.
5. Brain sends somatic motor signal to the external urethral spincter- with help from the spine- it is relaxed (VOLUNTARY).
6. Micturition