topic 11. powerpoint 11.1

Question 1

What are the 3 parts of a nephron?

Answer 1

cortex- outer medulla- inner medulla

Question 2

3 parts of nephron are
Where do we find..
Afferent arteriole
glomerulus
proximal tube
distal tube
loop of henle
collecting duct

Answer 2

Afferent arteriole- cortex
glomerulus- cortex
proximal tube-cortex
distal tube-cortex
loop of henle- outer medulla
collecting duct- inner medulla

Question 3

filtration occurs in what of the three parts of the nephron

Answer 3

cortex

Question 4

at the proximal end the nephrons forms

Answer 4

bowman capsule, which is around a ball of capillaries

Question 5

The fluid in the bowman capsule is called what

Answer 5

filtrate,

Question 6

Filtrate travels through the nephron, whatoccurs?

Answer 6

reabsorbtion and secretion

Question 7

explain process filtrate travels through in nephron

Answer 7

drains into the collecting ducts
and renal pelvis- ureter-urinary bladder-urethra

Question 8

Explain the process of filtration

Answer 8

we know filtration occurs in glomerulus but to be more specific…
There are spaces between endothelial cells of glomerular capillaries and Bownman capsule, very small. So proteins and blood can’t pass through but other can

Question 9

How does pressure relate to filtration?

Answer 9

capsule because the large diameter and less resistance, retain pressure to drive filtration into bowman

Question 10

What is the important of efferent arterioles and filtration?

Answer 10

Efferent arterioles: receives blood from the glomerulus; has smaller diameter, blood “backs up” (dam) in the glomerulus, keeping pressure high

Question 11

What substances enter through high pressure filtration?

Answer 11

water,
glucose, amino acids, sodium chloride and urea

Question 12

ultrafiltration

Answer 12

type of high pressure filtration

Question 13

filtrate that accumulates things like water, glucose, amino acids due to ultrafiltration, are called what?

Answer 13

fluid formed in this way is called glomerular filtrate

Question 14

What is the main function of the proximal tube?
By what mechanism?

Answer 14

Main function: reabsorption of water, ions and nutrients back into the interstitial fluid
Na+/+ exchanger and Na+/K+ pumps
positive ions creates a voltage gradient, causing absorption of cl-

Question 15

proximal tube secretes and absorbs what

Answer 15

secretes H+ into filtrate
absorbs: na+, cl-,k+, hco3

Question 16

in proximal tube, cl- flows out causing

Answer 16

water follows salt, filtrate is hypoosmotic

Question 17

during reabsorption , what transports big things like glucose or amino acids?

Answer 17

membrane proteins actively transport it

Question 18

Explain descending and ascending in loop of henle

Answer 18

Descending limb, water reabsorbed passively[water/membrane permeable/osmosis/psotive feedback] to interstual fluid because Na+ and Cl- is reabsorbed, falliated by thin walls of vasa recta. As it goes downward towards medulla, osmolarity increases. At bottom, isomotic. Ascending , active transport of Na+/Cl-, [membrane impermeable to water]creating urine that is hyperosmotic to blood.

Question 19

What mechanism helps maintain concentrated urine?

Answer 19

Loop of Henle and Vasa recta facilitates
counter-current multiplierwhich helps retain concentration gradient

Question 20

vasa recta is located

Answer 20

The vasa recta is located around the Loop of Henle in the medulla region of the kidney.

Question 21

In the counter-current multiplier: Flow of filtrate through the LoH is in the ___direction from the flow of blood
through the vasa recta.

Answer 21

opposite

Question 22

why doesn’t the water that moves out of the descending LoH dilute the concentration of
the interstitial fluid?

Answer 22

Because the vasa recta is reabsorbing the water (due to oncotic pressure
of blood).
vasa recta capillaries have fenestrae (pores) that makes them highly permeable to water
and solutes, allowing for equilibration.

Question 23

How is Urea important to counter current multiplier?

Answer 23

Urea plays a role in this process by diffusing out of the collecting duct and into the interstitial fluid of the medulla. This increases the osmolarity of the medulla, further enhancing the concentration gradient. The high concentration of urea in the medulla helps to maintain the high osmolarity needed for water reabsorption in the loop of Henle.

Question 24

distal convuluted tube, what is reabsorbed and secreted?

Answer 24

reabsorbed: Na+, cl-, h20, hco3
secreted: K= andH+

Question 25

What is the role of the duct?

Answer 25

function: to concentrate urine
duct descends, there is
an increasing solute
gradient in the medulla
H2O moves out of the duct
Some urea is passively
transported out of the duct,
which adds to the
increasing solute gradient in
the medulla
H+ is secreted into the
duct