💧

Understanding the Anatomy of the Urinary System

Apr 27, 2025

Anatomy of the Urinary System Lecture

Lecture Overview

  • Topics Covered: Anatomy of the urinary system and anatomy of the reproductive system.
  • Materials Used: Urinary lab outline on the left, BlackBoard PowerPoint for reproductive structures on the right.
  • Resources Provided: Pre-labeled diagrams of reproductive structures.

Urinary System Anatomy

Key Structures and Models

  • Models Used:
    • Incomplete model missing urinary bladder.
    • Complete model with visible kidneys, ureters, urinary bladder, and partial urethra.

Important Structures to Identify

  • Kidneys: Two kidneys visible with detailed aspects like renal capsule (fibrous capsule), hilum, renal cortex, and renal medulla.
  • Ureters: Visible connecting kidneys to the (missing) bladder in the incomplete model.
  • Urinary Bladder: Clear view in complete model; key features include serosa on top, muscle layer, and internal structures like trigone.
  • Urethra: Small visible part in the complete model.

Urinary Bladder Details

  • Layers: Serosa and Adventitia
    • Serosa covers the top; sides have adventitia.
  • Muscle Layer: Detected as orangey-tan layer.
  • Submucosa: Pink area beneath the muscle.
  • Mucosa: Contains rugae (wrinkles) and transitional epithelium.
  • Internal Structures:
    • Trigone: Triangular structure, ureteral openings.
    • Internal and External Sphincters: Internal within bladder wall; external outside bladder in urogenital diaphragm.

Kidney Anatomy

Main Parts

  • Renal Capsule: Also known as fibrous capsule.
  • Renal Cortex: Surrounds the outside, just beneath the capsule.
  • Renal Medulla: Contains pyramids and columns.
  • Renal Papillae: Tips of pyramids where urine collects.

Internal Structures

  • Calyces: Minor calyces collect from papillae, join into major calyces, then form the renal pelvis.
  • Ureter: Drains the pelvis.
  • Hilum: Entry/exit point for vessels and ureter.

Nephron Structure

  • Glomerulus and Bowman's Capsule: Start of filtration.
  • Proximal Convoluted Tubule: Orange in models.
  • Loop of Henle: Descending and ascending limbs (transition from orange to purple).
  • Distal Convoluted Tubule: Purple and convoluted.
  • Collecting Ducts: Yellow, lead into papillary ducts.
  • Types of Nephrons:
    • Cortical Nephrons: Short, mostly in cortex.
    • Juxtamedullary Nephrons: Long, extend into medulla.

Circulation and Blood Flow

  • Arteries: Renal artery -> Segmental -> Interlobar -> Arcuate -> Cortical Radiate (Interlobular).
  • Veins: Cortical Radiate -> Arcuate -> Interlobar -> Renal vein (no segmental veins).
  • Nephron Blood Flow:
    • Afferent arteriole -> Glomerulus -> Efferent arteriole -> Peritubular capillaries (or vasa recta).
    • Blood exits through cortical radiate vein.

Additional Details

  • Juxtaglomerular Apparatus: Contains juxtaglomerular cells and macula densa; regulates blood pressure by releasing renin.
  • Fenestrated Capillaries: Enhance filtration with pores.

Break

  • Next Topic: Reproductive system.
  • Break Duration: 15 minutes.

This concludes the notes on the urinary system section of the lecture. The next part will cover the reproductive system anatomy.

Full transcript