Renal Structure And Glomerular Filtration

Question 1

What are the Primary Functions of the Kidney?

Answer 1

1. Excretion of waste products: urea, uric acid, creatinine
2. Water and electrolyte balance
3. Avid/base balance
4. EPO and renin secretion
5. 1,25-dehydroxi-Vit D

Question 2

This part of the kidney is more susceptible to isquemia and is due to slow blood flow (⬇️PO2) ?

Answer 2

1. Medulla

Question 3

What are the 4 renal processes of the kidney?

Answer 3

1. Filtration
2. Reabsorption
3. Secretion
4. Excretion

Question 4

Where is plasma filtrated in the kidney?

Answer 4

Renal corpuscle

Question 5

Through what transport mechanism does secretion usually occur?

Answer 5

1. Active Transport

Question 6

How do you calculate the excretion rate (Er)?

Answer 6

Er = (Filtration - Reabsorption) + Secretion

Question 7

Nerve necessary for bladder filling phase ?

Answer 7

1. Hypogastric nerve.
2. Sympathetic NS
3. B3–> detrusor relaxation
4. Alpha-1: internal sphincter contraction

Question 8

Filling of the bladder activates and deactivates the following systems?

Answer 8

1. ⬇️Sympathetic

2. ⬆️Parasympathetic (Pelvic nerve) —> M3 receptor —> Detrusor contraction

Question 9

How is the external sphincter controlled, for contraction ?

Answer 9

1. Pudendal Motor Nerve (Nicotinic)

2. Void—> it’s inhibited

Question 10

2 mechanisms by which the kidney auto regulates ?

Answer 10

1. Myogenic response: ⬆️compliance—> ⬆️contraction

2. Tubuloglomerular feedback (TGF)

Question 11

TGF: what happens to RBF and GFR with ⬆️MAP?

Answer 11

1. ⬆️⬆️

Question 12

TGF: what happens to RBF and GFR with ⬆️Na delivery to the macula densa ?

Answer 12

1. ⬆️Vasoconstriction

2. ⬇️RBF and GFR

Question 13

TGF: what happens to RBF and GFR with ⬇️Na delivery in macula densa ?

Answer 13

1. Vasodilation

2 ⬆️RBF and GFR

Question 14

In order to maintain an ⬆️GFR, what will be the afferent/efferent interactions?

Answer 14

1. Afferent vasodilation (⬆️downstream pressure )

2. Efferent vasoconstriction (⬆️upstream pressure )

Question 15

Relationships between afferent/efferent arterioles to ⬇️GFR?

Answer 15

1. Afferent vasoconstriction (⬇️downstream pressure )

2. Efferent vasodilation (⬇️upstream pressure )

Question 16

What renal capillaries have ⬇️ hydrostatic pressure ?

Answer 16

Peritubular capillaries

Question 17

Normal GFR?

Answer 17

1. 120 ml/min

2. 180L/day

Question 18

Main starling force for GFR?

Answer 18

1. Glomerular Capillary Hydrostatic Pressure

Question 19

Main starling force that drives reabsorption in the tubules ?

Answer 19

1. Tubular capillary Oncotic Pressure

Question 20

Both capillary endothelial cells and GBM have this property that repels protein filtration?

Answer 20

1. Negatively (-) charged proteins and particles

Question 21

Plasma concentration/filtered concentration ratio for a substance freely filtered by kidney?

Answer 21

1.0

Question 22

How do you calculate filtration fraction ?

Answer 22

FF= GFR/RPF

FF= (120ml/min)/(600ml/min)

FF= .20 or 20%

Question 23

What does an ⬆️FF do to the peritubular capillary oncotic pressure?

Answer 23

1. ⬆️⬆️

2. ⬆️⬆️Reabsorption

Question 24

What does a ⬇️FF due to peritubular capillary oncotic pressure ?

Answer 24

1. ⬇️⬇️Oncotic pressure

2. ⬇️⬇️Reabsorption

Question 25

What does an ⬆️ in sympathetic function produce in renal function tests?

Answer 25

1. Vasoconstriction of AA>EA 2. ⬇️GFR < ⬇️⬇️RPF 3. ⬆️FF 4. ⬆️peritubular capillary oncotic pressure 5. ⬆️tubular reabsorption 6. ⬇️Glomerular capillary hydrostatic 7. ⬇️peritubular capillary hydrostatic

Question 26

What does angiotensin II cause to the renal function tests?

Answer 26

1. AA ⬆️< EA ⬆️⬆️ vasoconstriction 2. ⬆️GFR / ⬇️RPF 3. ⬆️FF 4. ⬆️Hydrostatic Capillary Pressure 5. ⬆️Peritubular Oncotic Pressure 6. ⬇️Peritubular Hydrostatic Pressure 7. ⬆️Peritubular reabsorption

Question 27

What does a combination of both sympathetic and angiotensin II do to kidney function?

Answer 27

1. ⬇️GFR/ ⬇️⬇️RPF 2. ⬆️FF 3. ⬆️Peritubular Oncotic Pressure IN A FEW WORDS: ⬇️GFR and ⬆️reabsorption

Question 28

Endogenous substances that protect kidney from ischemia during stress?

Answer 28

1. PGD’s —> protect kidneys countering sympathetic vasoconstriction in AA

Question 29

Uses of ACE inhibitors and ARB in kidney conditions?

Answer 29

1. CKD 2. Nephrotic Syndrome ⬇️GFR

Question 30

ACE inhibitors and ARB contraindications?

Answer 30

1. AKF (⬇️GFR) -> 😵 2. Bilateral Renal Stenosis (⬇️⬇️GFR) —> death GFR depends on EA vasoconstriction. If you inhibit ACE or AII—> 😵

Question 31

ACE inhibitors and ARB can cause this type of Renal Tubular Acidosis?

Answer 31

1. Type IV 2. ⬇️Hypoaldosteronism 3. ⬆️Hyperkalemia