Assorted Content
What influences how concentrated you can make filtrate?
The length of the Loop of Henle
How does the body control blood pH?
Through the lungs (respiratory) and the kidney (metabolic)
How does the ionic concentration gradient differ between the filtrate and interstitial fluid from the top of the loop to the bottom?
As filtrate reaches the bottom of the loop its ionic concentration is very high. The ionic concentration in the interstitium is only half that of the filtrate to encourage passive ionic diffusion in the ascending limb.
What is the job of the proximal tubule?
Why are humans unable to stop creating filtrate?
We have to get rid of substances that may accumulate and be toxic to our bodies, producing filtrate is the method that evolved.
True or False: Afferent and efferent arterioles are the only places blood flow is found in nephrons.
If the PCO2 in a person's body increases, what most likley is happening to the [HCO3-]?
In what way is urea important in the countercurrent multiplier system?
Urea helps maintain the difference in concentration between the cortex and medulla, ensuring it remains super salty in the medulla.
Which hormone is primarily involved in controling blood volume?
Aldosterone
Distal tubule
How do some proteins act as effective buffers in the blood?
They are able to bind to H+ ions when the plasma [H+] is high and give up H+ when the plasma [H+] is low.
How does the body fix a respiratory alkalosis?
Through full renal compensation in the lowering of [HCO3-] to restore normal pH.
Why does the osmolarity of the interstitium not change when water is being absorbed?
There is such a large amount of dissolved stuff in the interstitium adding some water does not have a noticeable effect.
Does GFR increase or decrease when you vasodilate the afferent arteriole?
Increase; the wider the AA the more blood flows through the glomerulus, increasing pressure in the GC which increases GFR.
Why would secretion be useful?
If the body wanted to get rid of something, but not all of it was filtered, some would need to get secreted as well.
True or False: The kidneys only filters a little bit of plasma each day.
False; GFR is around 180 L/per day, meaning our 3 liters of plasma is filtered 60 times a day.
What is a metabolic acidosis and what is unique about the way the body handles it?
What are the two jobs of the thick and thin ascending limbs and why is it important they are different?
Thick actively pumps out ions while thin allows passive diffusion. The thick ascending limb is able to pump out ions fast enough to maintain osmolarity difference between filtrate and interstitial fluid so passive ionic diffusion may continue.
You want to create really concentrated urine. What would be happening at the collecting duct to allow this?
ADH would signal for aquaporins to be put in the membrane of the collecting duct, allowing water to be reabsorbed from the filtrate.
Where does the majority of reabsorption occur in the nephron?
The proximal tubule; it doesn't care what is being reabsorbed, it reabsorbs everything the body says it needs.
At what point in the kidney is filtrate now called urine? What is the reason for this change in the name?
Do you know how to find your way around a davenport diagram?
Let's find out!
What advantage do humans have in the countercurrent multiplier system?
Massive reabsorption capacity in the closely regulated concentration gradient throughout the kidney.
Explain how osmolarity impacts GFR.
Fluid moving past the glomerular capillary and bowman's space is going to want to move toward the place with a higher osmolarity. The blood has more dissolved stuff in it that GC/BS, so the osmotic pressure is working against GFR in wanting to retain a higher volume than what is filtrated.
Why filter sodium if you are just going to reabsorb it?
Glomerular space has to be big enough to filter the small stuff we don't want, meaning the small stuff we DO want also has to get filtered and then reabsorbed.