The Urinary System Functions Homeostasis of blood p
The Urinary System Functions: Homeostasis of blood p. H, volume and electrolytes Components: • Kidneys – Produce urine • Ureters • Urinary bladder • Urethra
Retroperitoneal Location Renal capsule Inner layer lines renal sinus Adipose capsule Renal fascia
Right Kidney lower
Renal Anatomy Outer renal cortex Central renal pyramid Inner renal sinus
Inner Kidney • 6 -18 renal pyramids – Renal papillae project into renal sinus • Renal columns • Renal Sinuses filled with Adipose • Major calyx • Minor calyx • Lead to spaces and renal sinus – Continuous with ureter
Blood Flow
• • • Renal artery Segmental artery Interlobar artery Arcuate artery Afferent arteriole Veins carry same names
The Nephron • • Renal corpuscle Proximal convoluted tubule (PCT) Loop of Henle (nephron loop) Distal convoluted tubule (DCT) – Then on to collecting system • Connecting tubule • Collecting duct • Papillary duct
Histology
Two Nephrons types • ~85% are cortical nephrons – Short loops of Henle – Efferent arteriole provides blood to peritubular capillaries • Juxtamedullary nephrons – Closer to medulla – Loops of Henle extend deep into renal pyramids
Renal Corpuscle
Glomerulus – Fenestrated Capillary bed • Thick membrane – Lamina densa • Blood arrives at vascular pole of glomerulus – Afferent arteriole • Blood departs via efferent arteriole – Peritubular capillaries – Vasa recta
Proximal Convoluted Tubule • Actively reabsorbs – Nutrients (glucose and amino acids) – Ions (K+, Na+, Cl-) – Small plasma proteins
Loop of Henle Descending limb Ascending limb • Each one has thick and thin segment • Water balance • Ascending limb delivers fluid to DCT Distal Convoluted Tubule • • Actively secretes ions and other materials Reabsorbs sodium ions
Bladder
Bladder Histology
Urethra
Male Urethra Internal and External Urethral Sphincters Prostate gland Incontinence Retention Cystitis and Urethritis
Sphincters of Urethra
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