Lecture 1: Renal Physiology Review Flashcards
In which 2 compartments are protein levels the highest?
1) ICF compartments
2) Vascular compartments
What is the pressue generated by large molecules (like proteins) in solution that are impermeable to membranes?
Oncotic (colloid osmotic) pressure

Which 4 indicators can be used to measure ECF?
- 22Na+
- 125I-iothalamate
- Thiosulfate
- Inulin
How is ICF volume calculated?
TBW - ECF = ICF
Why can albumin (125I-albumin) be used to measure plasma volume?
Does not cross plasma membranes
How is interstitial fluid volume calculated?
ECF - plasma = ISF
ECF osmolality is driven (primarily) by?
Where are the concentrations of Na+ greatest between the vasculature, ICF, and interstitial fluid (rank them)?
- Na+ and Cl-
- [Na+] vasculature > [Na+] interstital fluid > [Na+] ICF
ICF osmolality is primarily driven by what ion(s)?
K+
ECF osmolality controls ______ volume
ECF osmolality controls ICF volume
All solutes that enter or leave the body do so via the?
ECF
Hypernatremia is defined as plasma [Na+] >?
plasma [Na+] > 146 mEq/L

Hyponatremia is a defined as plasma [Na+]
plasma [Na+] < 136 mEq/L

How is filtration rate calculated (equation)?
What are the components of the equation (i.e., Pc, Pi, πc, πi..)?
Filtration rate = Kf[(Pc−Pi)−σ(πc−πi)]
- Pc = hydrostatic pressure within capillary
- Pi = hydrostatic pressure of interstitial fluid
- πc = oncotic pressure of plasma
- πi = oncotic pressure of interstitial fluid
How is anion gap calculated?
Anion gap = [Na+] - ([Cl-] + [HCO3-])
When IV 0.9% NaCl (normal saline) is added to ECF what change occurs to osmolality and volume?
- No change in osmolality
- Only volume of ECF is increased

When IV 3% NaCl (hypertonic) is added to ECF what change occurs to osmolality and volume?
- Osmolality increases and pulls water from ICF into ECF
- Increased ECF volume and decreased ICF volume = cells shrink

When IV 0.45% NaCl (hypotonic) is added to ECF what change occurs to osmolality and volume?
- Osmolality of ECF decreases and water moves out of ECF into the ICF to equilibrate = cells swell
- ECF and ICF volumes BOTH increase

What is the stimulus for Angiotensin II in the kidney?
Effects on GFR and RBF?
- ↓ ECF volume = stimulus
- Causes ↓ in GFR and ↓ RBF

What are the 5 stimuli for Endothelin release in the kidney?
Effect on GFR and RBF?
- ↑ Stretch, Angiotensin II, bradykinin, epinephrine, ↓ ECF volume = stimulus
- Causes ↓ GFR and ↓ RBF
What are the 2 stimuli for release of Prostaglandins in the kidney?
Effects on GFR and RBF?
↓ ECF volume and ↑ shear = stimulus
- No change/↑ GFR and ↑ RBF
What are the 6 stimuli for NO release in the kidney?
Effects on GFR and RBF?
- Stress, shear stress, ACh, histamine, bradykinin, and ATP = stimulus
- ↑ GFR and ↑ RBF
What are the 2 stimuli for Bradykinin release in the kidney?
Effect on GFR and RBF?
- Prostaglandins, ↓ ACE = stimuli
- ↑ GFR and ↑ RBF
What is the stimulus for Natriuretic Peptides (ANP, BNP) in the kidney?
Effect on GFR and RBP?
- ↑ ECF volume = stimulus
- ↑ GFR and no effect on RBF
Caution should be taken when administering what drug to hypertensive pts, renal stenosis pts, and patients on diuretics?
NSAIDs due to interference with PGE2 —> Na+ retention









