The Nephron- Renal tubule

Question 1

How long is the renal tubule?

Answer 1

3 cms

Question 2

What three parts make the renal tubule?

Answer 2

1- Proximal convoluted tubule (PCT)
2- loop of Henle, which concentrates
3- Distal convoluted tubule (DCT)

Question 3

The renal tubules are surrounded by ______ ______ and ________ _______.

Answer 3

Peritubular capillaries

Vasa recta

Question 4

What is the function of peritubular capillaries and the vasa recta?

Answer 4

These small blood vessels allow the reabsorption of the kidney to proceed

Question 5

Along the PCT, the epithelial cells have a microvilli_____ ______ on their apical surface (facing the filtrate) to allow them to bring back, or _______ some filtered water and solutes that the body can still use

Answer 5

brush border

reabsorb

Question 6

Reabsorbed material will then go across the basal portion of the ______ cells, out into the ___ and finally towards surrounding blood vessels and thus, back into the _____..

Answer 6

epithelial
ECF
Blood

Question 7

The kidneys reabsorb ___L of 180L filtered daily.

Answer 7

179L

Question 8

The body must get rid of some ions and substances that are toxic or not needed. This process is called:

Answer 8

secretion

Question 9

From the blood vessels along the PCT and DCT, these unwanted substances will be ______ _______ into the filtrate.

Answer 9

actively transported

Question 10

90% of K+ are filtered, but most are _____ it’s fine-tuned by secretion.

Answer 10

reabsorbed

Question 11

What is hyperkalemia?

Answer 11

More K+ A less negative membrane potential, therefore easier action potentials and cardiac arrest

Question 12

What is hypokalemia?

Answer 12

Less K+ More negative membrane potential- hyperpolarized, leads to arrhythmias

Question 13

How is ammonia formed in the body?

How is is secreted?

Answer 13

As a byproduct of protein metabolism

Is changed to urea and secreted

Question 14

What is BUN

Answer 14

Blood
Urea
Nitrogen

Question 15

What does BUN measure? In general, and specifically?

Answer 15

Evaluates kidney function

Measures nitrogen in the blood (from urea)

Question 16

If glomerular filtration decreases severely, then BUN ______. What is the tx?

Answer 16

Rises steeply.

pt must minimize protein intake

Question 17

Penicillin is ______ filtered from the blood. Can _____ it in urine. Must have _____ doses to counter secretion

Answer 17

Rapidly
Smell
Several

Question 18

The nephron _______ blood

The nephron ______ needed liquid and solutes

Answer 18

Filters

reabsorbs

Question 19

The nephron _______ what the body doesn’t want or need at the moment, thus forming the final product: ______

Answer 19

Secretes

urine

Question 20

What is obligatory water loss? In mL?

Answer 20

The body must excrete 400mL of urine/day to rid the body of wastes
OR- the amount of urine that must be excreted to stay healthy

Question 21

What is azotemia?

Answer 21

An excess of urea in the blood caused by insufficient urine output

Question 22

Where does concentration of urine occur?

Answer 22

In the renal pyramid

Question 23

In the pyramid there are many tubes:
Tubes that run down and up– ____ ___ ______
Vessels that run down and up- _____ ______
Tube that runs down only- _______ ______

Answer 23

Tubes that run down and up– loop of Henle
Vessels that run down and up- vasa recta
Tube that runs down only- collecting duct
** Many tubes running next to each other with interstitial tissue around them

Question 24

What is countercurrent?

Answer 24

Fluid is going one way and right next door going the other way

Question 25

The kidney has a unique and large ______ gradient.

Answer 25

Vertical

Question 26

How do the vasa recta maintain the vertical gradient?

Answer 26

1- with sluggish flow

2- Freely permeable to Na+ Cl- and H2O

Question 27

What mechanism concentrates urine?

Answer 27

Countercurrent multiplier mechanism

Question 28

How does the countercurrent multiplier mechanism work?

Answer 28

The juxtamedullary nephrons long loops of Henle establish the vertical osmotic gradient and the vasa recta prevent the dissolution of the gradient while providing blood to the medulla.

Question 29

The nephron loop is a _______ because it multiplies the salinity deep in the medulla and a ________ mechanism because it is based on fluid flowing in opposite directions in adjacent tubules.

Answer 29

multiplier

countercurrent

Question 30

How does countercurrent multiplier work in the descending tubule?

Answer 30

Highly permeable to H2O, but doesn’t actively extrude Na+ or Cl-
Relatively impermeable to solutes

Question 31

How does the countercurrent multiplier work in the ascending tubule?

Answer 31

Actively transports Na+ Cl- out of tubes into surrounding tissue
Is always impermeable to H2O, so slat leaves without H2O following

Question 32

Why is there a different in mOsm between the ascending and descending tubules?

Answer 32

Always a 200 mOsm difference between the two tubes- reflects the power of the ascending tubes NaCl pumps

Question 33

The more “___” the ascending limb extrudes, the more concentrated the delivered fluid will be

Answer 33

salt

Question 34

ADH works on the _____ _____

Answer 34

Collecting duct

Question 35

What are polyuria, oliguria, and anuria?

Answer 35

polyuria- More than 2L of urine/day
oliguria- Less than 500mL of urine/day
Anuria- 0-100 mL of urine a day