The Urinary System

I. Kidney Anatomy Diagram Diagram

A. External Anatomy

i. Three supportive tissue layers surrounding kidney: renal capsule, adipose capsule, and renal fascia

ii. Kidney contains a structure (hilus) where the renal arteries and vein are located as well as the beginning of the ureters

B. Internal Anatomy Diagram

i. Kidney is composed of three specific regions: cortex, medulla, and pelvis

ii Internal structures: renal column, renal pyramid, papilla, and minor and major calyx

C. Blood Supply Diagram

i. Renal arteries: segmental --> lobar --> interlobar --> arcurate --> interlobular (cortical radiate)

ii. Renal vein - no segmental or lobar <-- interlobar <-- arcuate <-- interlobular (cortical radiate)

D. Nephrons Diagram

E. Juxtaglomerular Apparatus Diagram

II. Kidney Physiology

A. Overview  Diagram Diagram

B. Glomerular Filtration

  1. Filtration membrane is thousands of times more permeable to water and solutes than other capillary membranes
  2. Glomerular blood pressure is higher than that of other capillary beds, resulting in a higher net filtration pressure
  1. Fenestrated capillary (glomerular) endothelium: capillary pores prevent passage of blood cells
  2. Visceral membrane made of podocytes (branching epithelium); basement membrane restricts all but smallest proteins
  3. Intervening basement membrane; podocyte's pedicles (filtration slits) provide no restriction in passage of molecules

C. Tubular Reabsorption

D. Tubular Secretion Diagram

  1. disposing of substances not already in the filtrate
  2. eliminating undesirable substances (urea & uric acid) that have been reabsorbed by passive processes
  3. ridding the body of excessive ions
  4. controlling pH of blood

III. Ureters, Urinary Bladder, Urethra Diagram

A. Ureters

  1. inner mucosa (covering lumen) composed of transitional epithelium and lamina propria
  2. muscularis, composed of circular and longitudinal smooth muscle
  3. adventitia, composed of fibrous connective tissue

B. Urinary Bladder

  1. mucosa with transitional epithelium
  2. muscular layer (detrusor muscle) with longitudinal and circular muscles
  3. fibrous adventitia

C. Urethra

IV. Clinical