Renal Physio

Question 1

• Role of the kidney?
• Breakdown of volume compartments?
• Kidney GFR in L/day?
• RDS in RAAS? What levels are constant?
• JGA located where? Granular cells secrete?
• 2 GFR equations?
• Normal net pressure? How is so much filtered?
• Afferent constriction leads to? A and E constr?

Answer 1

• Maintain composition and volume of EC fluid
• ECF = 15 L (12 inter; 3 plasma); ICF = 27 L (3L RBC’s)
• GFR = 5.2 L/min * 0.25 (RBF) * 0.5 (plasma %) * 0.2 (FF) * 1440 min = 190 L/day
• Renin stim; A-gen and ACE
• Affer.; Renin
• GFR = k (delta P) = k (Pgc-Pt-onc.gc)
• 6 mm/hg; Low R and high SA
• Low Pgc, GFR, RBF; Very low RBF

Question 2

• Lower RBF = Filt. fraction? Osm. GC? GFR?
• PG’s: produced where? Secreted? Effect?
• After isotonic prox tubule?
• Flow equation for interstitium?
• Incr. tub. flow rate =?
• What signals JGA when [NaCl] is high?

Answer 2

• Incr; Incr; Modest decrease
• Renal intersitium medulla; AT2; dilate afferent
• Interstitium is hypertonic
• F = k (Pint + osm.cap - Pcap - osm.int)
• Lower reabsorption
• macula densa

Question 3

• Normal K+ amount?
• K+ reabsorbed via?
• K+ feedback loop works via? (2 steps)
• How does flow rate effect secretion?
• Alkalosis can lead to?

Answer 3

• 3.5-5 mM
• Obligatory with variable secretion
• Incr. K+ = stim. of adr. cortex and aldo release; 1 = Increased BL K+ pumps 2 = Increased pumps to Lumenal side
• Slow = Less K+ secreted
• Hypokalemia

Question 4

• EABV is? Low volume? High volume? Intrarenal?
• Antinaturieses hormones? Natuireses hormones?
  1. ) PT: Blocks CA? Causes? How?
  2. ) Loop: Drugs block?
  3. ) DT: Block?
  4. ) CD: 2 types?
• D5W: Equilibrates across? Saline? Plasma?

Answer 4

• Effective arterial blood volume: sensed on arterial side; sensed on venous side; macula densa
• AT2, Aldo, catechol, ADH; NP’s, PG’s, BK’s, dopamine
• Acetazolamide; MA; increased loss of HCO3-
• Na/K/2Cl channel
• Na/Cl cotrnasporter
• Na channel blocker and Aldo inhibitor
• Plasma, inter and IC; Plasma and Inter; Plasma

Question 5

• Normal Na+?
• What increases Aldo synthesis? (3)
• Sweat example?
• ECF regulation primarily what? With what?
• Volume loss of >10%
• Effect of ANP from cardiocytes?

Answer 5

• 135-145 mM
• ACTH, K+, AT2
• Incr. osmolality so incr. ADH prod.
• Osmolarity with emergency low volume overload
• Volume input dominates effects on ADH
• Lowers ADH, renin, aldo and increases A and E dilation

Question 6

• Nephron GFR equation?
• Cr is measure of?
• Clearance eq?
• SNGFR proportional to?
• Pre renal azotemia: GFR? RPF? Cr? Urine Na? why?
• Post renal: Due to? GFR?
• Intrinsic: GFR? due to?
• FENa? 2%?

Answer 6

• GFR = Ux * V/Px
• GFR
• Clx = Xe/Px
• Pgc
• Low; Low; High; Low; avid reabs.
• Obstruction with low GFR
• Low; kidney injury
• FENa = (Una/Pna) / (Ucr/Pcr); Prerenal; other

Question 7

Lab Values:

• Na? K?
• Cl?
• Cr? BUN?
• HCO3-?
• Phos? Ca?
• Osm?
• pH eq?

Answer 7

• 135-145; 3.5-5
• 98-106
• 0.6-1.2; 7-18
• 18-24
• 4; 8.5-10.5
• 282-288
• pH = 6.1 + log ([HCO3-] / 0.03*PaCO2)

Question 8

• Serum Osm equation?
• What is hyponatremia? Symptoms?
• Euvolumic hyponatremia cause?
• Hypernatremia? Often due to? Test? Be careful of? What is good treatment?

Answer 8

• Sosm = 2*Na + BUN/2.8 + Glucose/18
• Serum Na is low; B symptoms
• Excess ADH secretion
• Renal or extra renal water loss exceeds sodium loss or addition of hypertonic fluids; lack of ADH (insensitive or not secreted); nasal DDAVP; CE; D5water

Question 9

• Whats shifts K+ into cells? (6)
• Physiological effects of hyper/hypo K+?
• Hypo K+ treatment?
• Treatment with hyper K+ with ECG changes?

Answer 9

• Ca, insulin, glucose, aldo, bicarb, catecholamines
• NM and cardio
• Digitalis
• Ca glutanate, sodium bicarb, glucose/insulin, K exchange resin, albuterol, hemodialysis