Cheatography
https://cheatography.com
1. Body Fluids
2. The Nephron, Reabsorption and Secretion, Renal Clearance, Renal Blood
Flow (RBF) and Glomerular Filtration Rate (GFR)
3. K Regulation
4. Renal Regulation of Urea, Phosphate, Calcium & Magnesium 5. Concentration and Dilution of Urine
6. Acid-Base Balance
7. Integrative Examples
This is a draft cheat sheet. It is a work in progress and is not finished yet.
Body Fluids
| |
%of Body weight |
Markers |
Major Cations |
Major Anions |
TBW |
60% |
Titrated water, D2O antipyrine |
-- |
-- |
ECF |
20% |
Sulfate, Inulin, Mannitol |
Na |
Cl, HCO3 |
Plasma |
5% (25% of ECF) |
RISA (Radioactive iodinated Serum Albumin), Evans Blue |
Na |
Cl, HCO3 |
Interstitial Fluid |
15% (75% of ECF) |
ECF-plasma volume (indirect) |
Na |
Cl, HCO3 |
Intracellular Fluid |
40% |
TBW-ECF (indirect) |
K (Mg is also an ICF Cation |
Organic Phosphate, Protein |
60-40-20%(75-25%) RULE (WATER,ICF,ECF(IF,PLASMA)
|
Endocrine Function of the Kidneys
Erythropoietin (EPO) |
From interstitial cells in peritubular capillary bed • Released in response to hypoxia → stimulates RBC proliferation in bone marrow • Chronic kidney disease (CKD) causes ↓ EPO → chronic anemia |
Calciferol (Vitamin D) |
• PCT converts 25-OH vitamin D3 → 1,25- (OH)2 vitamin D3 (calcitriol, active form) • Conversion is mediated by 1α- hydroxylase (which is upregulated by PTH) |
Prostaglandins |
Paracrine secretion vasodilates the afferent arterioles → ↑RBF • NSAIDs block the renal protective prostaglandin synthesis → afferent arteriole constriction → ↓GFR → Acute Kidney Injury (in low renal blood flow states) |
Dopamine |
From PCT cells • Promotes natriuresis • At low doses: dilates interlobular arteries, afferent arterioles, efferent arterioles → ↑ RBF • At high does: acts as vasoconstrictor |
|
Volume & Conc. Changes Across Compartments
| |
EXAMPLES |
ECF Vol |
ICF Volume |
Osmolarity |
Hematocrit |
Plasma Protein |
Isosmotic volume contraction |
Diarrhea, Burn |
↓ |
NC |
NC |
↑ |
↑ |
Hyperosmotic volume contraction |
Sweating, Fever, Diabetes Insipidus |
↓ |
↓ |
↑ |
NC |
↑ |
Hypoosmotic volume contraction |
Adreanal Insufficiency |
↓ |
↑ |
↓ |
↑ |
↑ |
Isosmotic volume expansion |
Infusion of Isotonic NaCl |
↑ |
NC |
NC |
↓ |
↓ |
Hyperosmotic volume expansion |
High NaCl Intake |
↑ |
↓ |
↑ |
↓ |
↓ |
Hypoosmotic volume expansion |
SIADH |
↑ |
↑ |
↓ |
NC |
↓ |
|
|
NEPHRON, RENAL CLEARANCE, RENAL BLOOD FLOW and GFR
Types of Nephron |
Cortical Nephron |
75% of Nephrons in the Renal Cortex. Short Loops of Henle and (+) Peritubular Capillaries |
Juxtamedullary |
25% of Nephrons in the Corticomedullary Junction. Long Loops of henle and (+) Vasa Recta |
• Structural and Functional Unit of the Kidneys
|
|
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