Renal II Flashcards
1
Q
What is the juxtaglomerular apparatus composed of?
A
- Macula densa
- Granular cells (secrete renin)
- Extraglomerular mesangial cells (secrete erythropoietin)
2
Q
Fxn of juxtaglomerular apparatus
A
Regulates:
- BP
- Blood cell production
- Rate at which kidneys filter fluid
3
Q
Chemical transmitters
A
Have direct effects on VSM Ca2+ channels
4
Q
Where does corticopapillary osmotic gradient take place?
A
Long loops of henle
5
Q
What does the “single effect” result in?
A
- Increased osmolarity in interstitial fluid & descending limb
- Decreased osmolarity in ascending limb
6
Q
What are the 3 steps to concentrate urine?
A
- Pump
- Equilibrate
- Shift
7
Q
Tubular fluid
A
- Progressively concentrated as it flows down descending limb
- Progressively diluted as it flows up ascending limb
8
Q
What kind of fluid leaves the loop of henle?
A
Dilute
9
Q
Countercurrent
A
Flow in opposing directions through the 2 limbs
10
Q
What is the essential component?
A
Active transport
11
Q
Vasa recta as countercurrent exchangers
A
- In medulla
- Have hairpin loops
- Descending limb: NaCl & urea in & H2O out
- Ascending limb: NaCl & urea out & H2O in
- Passive process, protects ISF gradient
12
Q
Fxn of vasa recta
A
- Deliver nutrients
- Remove excess Na+ & H2O
13
Q
How are wide fluctuations in K+ of ECF prevented?
A
By shifts of K+ btwn ICF & ECF:
- Liver
- Skeletal muscle
- Adipose tissue
14
Q
Hyperosmolarity
A
H2O flows from ICF to ECF
15
Q
What does exercise cause?
A
- Shift of K+ out of cells
- Slight increase in blood K+
