Skip to content
Tashrih
ExploreAtlasModulesCurriculum
Pricing
Step 1

Choose an organ

Step 2

Explore it in 3D

Tip

Drag to rotate · Scroll to zoom · Click a dot to learn more

Perfusing · a fifth of the output

The renal arteries pulse hard, the kidneys swell a beat later, and the ureters milk urine downward in slow waves.

  • Renal Cortex: Outer filtering layer
  • Renal Capsule: Fibrous shell — stretching it is what causes pain
  • Renal Medulla: Concentrates urine
  • Renal Pyramid: Wedge of collecting tubules pointing inward
  • Renal Artery: Delivers a fifth of the heart's output
  • Renal Vein: Returns filtered blood to the vena cava
  • Renal Pelvis: Funnels urine toward the ureter
  • Adrenal Gland: Endocrine gland riding on top, unrelated in function
  • Ureter: Carries urine
  • Hilum: The medial slit everything enters by — vein in front, artery behind it, pelvis behind both
  • Superior Pole: Upper end, capped by the adrenal gland and reaching the eleventh or twelfth rib
  • Inferior Pole: Lower end, the only part occasionally felt from the front on deep inspiration
  • Lateral Border: Convex outer edge; the plane beneath it is Brödel's bloodless line, the way in for a needle
  • Calices: Minor calices cup each papilla and merge into two or three major ones
  • Pelviureteric Junction: First of the three narrowings — where the pelvis funnels down into the ureter
  • Crossing of the Iliac Vessels: Second narrowing, at the pelvic brim where the ureter arches over the common iliac artery
Urinary System

Kidneys

The master filters · Renes
180 Lfiltered — about 99% reclaimed

Paired filtration organs that balance fluids, electrolytes, blood pressure, and waste removal.

Key facts

Size
Each is about a computer mouse
Weight
120–170 g each
Location
Either side of the spine below the ribs
Function
Filters blood and forms urine

Did you knowThey reclaim almost everything they filter — only about 1–2 L leaves the body as urine.

Study alongside
Step 3

Keep learning

Microscopic view

Renal cortex

Compare organs

Kidneys vs. liver

Function animation

Filters blood and forms urine

Clinical notes

Red flags

  • Urine output falling towards nothing is the kidney's loudest alarm — obstruction or shock until excluded.
  • Loin pain with fever and rigors is an infected, possibly obstructed kidney — an emergency needing drainage.
  • Visibly bloody urine without pain, especially past fifty, is a urinary-tract cancer until proven otherwise.
  • Kidney stones
  • Chronic kidney disease
  • Urinary infection
  • Glomerulonephritis
  • Polycystic kidney disease
  • Renal hypertension
  • Acute kidney injury
  • Nephrotic syndrome
Where it works

Urinary System

A filtration and reclamation plant that decides, litre by litre, what the blood keeps and what it loses.

Tashrih
MCQsDaily challengeFeedbackTermsPrivacyRefunds
Follow Tashrih
  • TikTok
  • Instagram