Renal Anatomy and Physiology Summary Notes (with diagrams)

Proximal Convoluted Tubule (PCT) Brush border cells Interstitial space Peritubular capillary
Renal Tubule 300 mOms/L
Glomerulus
Proximal convoluted tubule Distal convoluted tubule Glutamine
Late Ammonium
Renal Corpuscle Early Ammonium + HCO3
Renal Cortex




PTH Thiazide diuretics
Urea Medications
Bowman’s Capsule Na
Glucose Na Passive diffusion
Na Urea Urea
HCO3 Cl H+ Cl H2O H2O H2O
Urea Ca K ADH
Osmotic diuretics
H2O
325 mOsm/L Aldosterone Ca2+
Na+ Na+
NH4
Medications Na
Cl K+ K+
300 mOsm/L K Na/K
Na+
ATPase
Cl-
Ascending limb
GLUT1
Loop diuretics Na+ Na-glucose
Na, H2O Glucose
transporter
Na+ Glucose GLUT2
Renal Medulla




H+, K
H2O
600 mOsm/L K-sparing diuretics
Na+
Na-H exchanger
Na
Cl H+ Na-HCO3 Na+
Descending limb
cotransporter
Collecting duct H + HCO3 H + HCO3- HCO3-

H2CO3 Carbonic anhydrase II
1200 mOsm/L Carbonic anhydrase IV H2O + CO2 H2CO3
H2O + CO2

Renal Anatomy and Physiology
Loop of Henle Urine to ureter Filtrate

Diuretics Summary Note: ATPase
Collecting = both ions are going against [ ] gradient
Duct Brush border cells Interstitial space Peritubular capillary
400 mOms/L
Types MOA Indications Dosing SE Contraindications

ADH
Thiazides Hydrochlorothiazide, ↓ Na reabsorption in DCT Htn (1st line essential htn), HCTZ: Hypotension, Sulfa allergy,
chlorthiazide edema, idiopathic Htn: 12.5-25 mg PO od hypokalemia, polyuria pregnancy H2O
hypercalciuria and stones (max 50 mg/d)
Edema: 25-100 mg PO od Urea Aquaporin
Stones: 25-100 mg PO od

H2O H2O
Aquaporin
Principal cell
Ca2+

Loop diuretics Furosemide (Lasix) Blocks luminal Na/K/Cl CHF, Edema: 20-80 mg IV/IM/PO Hypovolemia, Hypovolemia,
transporter in thick pulmonary/peripheral q6-8h (max 600 mg/d) hypokalemia, metabolic hypokalemia K+ a-intercalated cell
ascending limb edema, Htn Htn: 20-80 mg/d PO od/BID alkalosis
↓ Na, K, Cl reabsorption


Cl- H+
K-sparing/ Spironolactone, Antagonizes aldosterone R Htn, CHF, hypokalemia Spironolactone: Edema, hyperkalemia, Renal insufficiency, H-K ATPase
Aldosterone eplenerone to ↓ Na at collecting duct Htn: 25-200 mg/d od/BID gynecomastia hyperkalemia, K+ K+
antagonists pregnancy Na+


Aldosterone H2O
Osmotic Mannitol (Osmitol) Non-reabsorbable solute Decrease intracranial and Mannitol: Transient volume Anuria, active cranial
Na+
Glycerol increases osmotic pressure intraocular pressure ↓ICP: 0.25-2 g/kg IV over expansion bleeding ENaC
Urea of filtrate; inhibits H2O RF/edematous states 30-60 mins Electrolyte Aquaporin
reabsorption at PCT and abnormalities
ATP-dependent
collecting duct K+ K pump Aldosterone
K+
Na/K Na+
ATPase
Principal cell Aldosterone
H2O Aquaporin
1200 mOms/L
Filtrate

, Renal Anatomy

Kidneys:
• Retroperitoneal, surrounded by renal capsule, adipose capsule, and renal fascia
• Renal hilum = ureter, renal arteries, renal veins, lymphatics, nerves
• L higher than R
• Functions: filtering blood, regulating blood pH/volume/pressure/osmolality, hormone production
• Filters 150 L of blood/day




Nephron:
• 1 million nephrons/kidney
• Basic structural functional unit of kidney
• Renal corpuscle = glomerulus + Bowman’s capsule
• Blood flow from afferent arteriole à glomerular capillaries à efferent arteriole à vasa recta
à renal venules
Renal tubules:
• Reabsorption and secretion between tubules and vasa recta
Glomerulus:
• Glomerular filtration barrier = endothelium, GBM, podocytes
• Particles positively charged, < 60 kDa
Cell types:
1. Mesangial cells: in between loops of glomerular capillaries; structural and produce vasoactive substances
2. Capillary endothelial cells (sinusoidal)
3. Podocytes (visceral epithelium): interdigitated foot processes form slit diaphragms
4. Parietal epithelium: lines interior of Bowman’s capsul;, contains podocyte progenitor population
5. Juxtaglomerular cells: smooth muscle cells lining afferent arteriole; produce and secrete renin