Liver vs. Kidney: Comparative Anatomy, Physiology, and Failure Patterns

The liver and kidneys are both vital organs, but they differ fundamentally in structure, function, regenerative capacity, and the consequences of their failure.

Comparative Overview

Feature	Liver	Kidney
Location	RUQ, under diaphragm	Retroperitoneal, T12–L3
Weight	~1.5 kg (largest solid organ)	~150 g each (paired)
Functional Unit	Hepatic lobule (hepatocytes)	Nephron (glomerulus + tubule)
Blood Supply	Dual: hepatic artery (25%) + portal vein (75%)	Renal arteries (20% CO)
Regeneration	Remarkable (up to 70% resection)	Limited (hypertrophy, not hyperplasia)
Primary Roles	Metabolism, synthesis, detox, bile, storage	Filtration, homeostasis, endocrine

Liver-Specific Functions

• Gluconeogenesis, glycogen storage, lipid metabolism.
• Synthesis: albumin, clotting factors, complement, lipoproteins.
• Detoxification: Phase I (CYP450), Phase II (conjugation), bile excretion.
• Immune: Kupffer cells, acute-phase proteins.

Kidney-Specific Functions

• GFR ~180 L/day → 1–2 L urine (selective reabsorption).
• RAAS → BP control; EPO → erythropoiesis; 1α-hydroxylase → active vitamin D.
• Acid-base: H⁺ excretion, NH₄⁺ synthesis, HCO₃⁻ regeneration.

Failure Patterns

• Acute Liver Failure: Coagulopathy, encephalopathy, cerebral edema—high short-term mortality.
• Chronic Kidney Disease: Silent progression → ESRD → dialysis/transplant; cardiovascular mortality dominant.

Both are irreplaceable; the liver has a regenerative edge, while the kidney has replacement therapy (dialysis).