Download 27. Renal Anatomy

The Renal System
2 Kidneys
- Produces urine
2 Ureters
- transports urine
1 Urinary bladder
- stores urine
1 Urethra
- conducts urine
to outside
3 Layers Surrounding the Kidney
Renal Capsule
- inner layer lines renal sinus
Adipose Capsule
- fat padding around kidney
Renal Fascia
- outermost layer
Transverse Section
Outer renal cortex
Inner renal medulla
Central renal
pyramid
Renal papilla
Minor calyx
Major calyx
Renal pelvis
Ureter
Calyx – ‘cup’
Pelvis = basin
Calyx - singular
Calicies - plural
There are 6-18 renal pyramids in a kidney:
- The renal papillae project into renal sinus.
Renal lobe
- Contains renal pyramid, overlying cortex, adjacent
renal column.
Collection of Urine
Minor calyx
Major calyx
Renal Pelvis (continuous with ureter)
Renal Blood Supply
• Renal artery
• Segmental artery
• Interlobar artery
• Arcuate artery
• Interlobular artery
• Afferent arteriole
Veins carry same names
The Nephron
The Nephron has 2 parts:
1. Renal Corpuscle
Glomerulus
Bowman’s Space
Bowman’s Capsule
2. Renal Tubule
Proximal convoluted tubule (PCT)
Loop of Henle (nephron loop)
Distal convoluted tubule (DCT)
~85% Cortical Nephrons
Short loop of Henle.
Efferent arteriole
becomes peritubular
capillaries.
15% Juxtamedullary
Closer to medulla.
Loop of Henle deeper.
Efferent arteriole
becomes vasa recta.
Juxtaglomerular Apparatus
Macula Densa – specialized portion of DCT.
Sits in between afferent and efferent arteriole
– for communication regarding renal function.
Juxtaglomerular (JG) Cells – specialized
cells, mostly surrounding afferent arteriole.
For changing diameter of afferent arteriole.
Glomerulus – Fenestrated Capillary bed
• Blood arrives at afferent arteriole.
Filtrate “filtered” at Glomerulus.
• Blood departs via efferent arteriole.
• Blood goes into a) Peritubular or
b) Vasa recta capillaries
• Blood exits via renal venule, vien.
The Nephron
Proximal Convoluted Tubule
• Actively reabsorbs
– Nutrients (glucose, amino acids)
– Ions
– Small Plasma proteins
• Lined with simple cuboidal epi
– With microvilli (brush border)
– Large surface area
Loop of Henle
Descending limb
Ascending limb
• Thin segment is simple squamous epi.
• Thick segment is simple cuboidal epi (no nicrovilli)
• For Water balance
Distal Convoluted Tubule
Actively secretes ions and other materials
Lined with simple cuboidal epi.
Collecting Duct
Lined with simple cuboidal epi.
Changes to simple columnar epithelium
deeper in the medulla.
Bladder is lined with . . .
Transitional epithelium