Renal Physiology Pt 1/4 (Basics)

Question 1

What are the roles of the kidney?

Answer 1

PHRREI

Question 2

What are the roles of the following ions in the body?

Na+
K+
Ca2+
H+/HCO3-

Question 3

What are the roles of the nephron (the functional unit of the kidneys)?

Answer 3

FRSE

Question 4

How many nephrons are there in 1 kidney?

Answer 4

~1 mil

Question 5

In PCT:

How much (volume of plasma) is filtered a day?

Filtrate osmolarity in PCT?

Is filtrate osmolarity same as that of plasma?

Answer 5

180L/day

300 mOsM

Yes! at PCT

Question 6

In collecting duct:

How much (volume of plasma) is excreted a day?

Filtrate osmolarity in collecting duct?

Answer 6

1.5L/day

50-1200 mOsM (depending on R/S at collecting duct)

Question 7

Filtration:
- what is filtered? + how many % of plasma passing through glom is filtered? what happens to the remaining?

• what is the 3-layer filtration barrier?
• Outline the process of filtration (incl. the filtration pressures w no.s at the glomerulus.)
• What is the normal net filtration pressure?

Question 8

Glomerulus + Bowman’s capsule =?

Answer 8

Renal corpuscle

Question 9

Eqn:
- filtered load = ?

• filtration coefficient?

Question 10

GFR:
- eqn?

• units?
• What’s the normal GFR daily? (in L/day –> mg/min)
• Eqn for urine flow rate? (rmb to convertfrom L/day to mg/min)

Question 11

If filtered load > excretion => is this net secretion/ net reabsorption?

Answer 11

net reabsorption

Question 12

If filtered load < excretion => is this net secretion/ net reabsorption?

Answer 12

net secretion

Question 13

What are 4 factors influencing glomerular filtration rate (NAPS)

Question 14

How is GFR autoregulated? (MTH)

Question 15

How to convert picomol to mmol?

Question 16

Creatinine:
- from?

• used for?
• why can it be used as a proxy of eGFR?
• thus, what’s the rls between serum creatinine and kidney fxn?

Question 17

Secretion:
- what (stuff) are usually secreted?

• what ion is not secreted?
• where does it occur? + brief process (mvmt of subst)?

Answer 17

• drugs & wastes to excrete and not/cldn’t be filtered through at gloms (note: 20% of plasma filtered only) + H+ to regulate pH (HCO3- excreted too but cuz [H+] main determinant of pH)

Question 18

(read through organic anion secretion in notes and note why its impt!)

Question 19

Reabsorption:
- What substs are reabsorbed? (NAWS)

• Where does reabsorption happen? Where is the MAIN site of most reabsorption (+ specific %es of solutes there)?

Question 20

What is trans- vs paracellular uptake of cells?

Question 21

Explain impt points in case studies of ions reabsorption:
- Na+ ?

• Glucose and a.a. ?
• Urea?

Question 22

Glucose:
- how much is filtered?
- how much is reabsorbed?
- renal threshold?

Question 23

Define renal threshold?

Question 24

Excretion:
- what is excreted?

• where does excretion happen?
• write the FRSE eqn for excretion?