The urinary system

Question 1

Kidneys: location and attachment

Answer 1

• Location: retroperitoneal, above waist

- attachment: renal fascia, enclosing perirenal fat

Question 2

gross features and innervation of kidney

Answer 2

A). Gross features

• renal capsule
• cortex: outer layer
• medulla: inner zone
• pyramids: trianguar zones within medulla
• minor calyces}
• major calyces} urine collection ducts
• renal pelvis }
• renal blood vessels
  ureter: single urinary exit tubule

B). innervation

• Sympathetic (from T10-T12); vasoconstriction that reduces urination
• Parasympathetic (from vagus branch)

Question 3

Microanatomy of the nephron

Answer 3

1. Tubular components:
   
   • glomerular capsule
   • proximal convoluted tubule
   • loop
   • distal convoputed tubule
   • collecting ducts
2. Vascular components:
   - Toward nephron:
   
   • interlobar artery
   • arcuate artery
   • interlobular artery
   • affarent arteriole
   • glomerulus (within glomerular capsule)
     - Away from nephron:
   • efferent arteriole
   • peritubular capillaries
   • interlobular vein
   • arcuate vein
   • interlobar veins

Question 4

Urination (urine formation):

Answer 4

1. glomerular filtration
2. tubular secretion
3. tubular reabsorption

Urine Flow Scheme:
collecting ducts—>minor calyx—>major calyx—> renal pelvis—> ureters—> urinary bladder—> urethra—> outside

Question 5

Ureters

Answer 5

1. Function and Location:
   - transport of urine from kidney to bladder retroperitoneal
2. Layers:
   - outer: fibrous connective tissue
   - middle: smooth muscle
   - inner: transitional epithelium

Question 6

Urinary bladder

Answer 6

1. Function and location
   - urine storage
   - midline in pelvic cavity
2. Layers and Features
   - lined by mucous membrane of transitional epithelium
   - detrusor muscle: multilayered smooth muscle
   trigone: smooth, triangular entrance/exit relationship inside bladder
   - internal sphincter: smooth muscle
   - external sphincter: skeletal muscle

Question 7

Urethra:

Answer 7

1. Function and Location:
   - urinary excretion
   - passes through “urogenital diaphragm”