L3.2: Epithelial and Connective Membranes

• • Simple organs
  • Covering and lining membrane
  • Contains epithelial tissue layer and connective tissue layer


  Epithelial membrane
• Definition

  • Dry membrane
  • Outermost protective boundary
  • Exposed to air

  Location

  • Skin

  Construction

  • Epidermis - keratinized stratified squamous epithelium
  • Dermis - dense (fibrous) connective tissue


  Cutaneous membrane
• Definition

  • Moist membrane
  • Lines all body cavities that open to the exterior, such as the hollow organs of:
  • Respiratory Tract
  • Digestive Tract
  • Urinary Tract
  • Reproductive Tract

  Location

  • Mouth & Esophagus - stratified squamous epithelium
  • Digestive Tract - simple columnar epithelium

  Construction

  • Epithelium - type depends on site
  • Lamina Propria - loose (areolar) connective tissue


  Mucous membrane (Mucosae)
• • Lines open body cavities that are closed to the exterior of the body
  • Line compartment in the ventral body cavity
  • Occurs in pairs (separated by serous fluid):
  • Parietal Layer
  • Parie = wall
  • Lines a specific portion of the wall of the ventral body cavity (outer close to the thoracic)
  • Visceral Layer
  • Covers the outside of the organ(s) in that cavity (inner wall close to the lungs)
  • Serous Fluid
  • Thin, clear fluid
  • Allows the organs to slide easily across the cavity walls without friction or pain


  Serous membrane (Serosae)
• Location

  • Peritoneum - abdominal cavity
  • Pleurae - surrounding the lungs
  • Pericardia - around the heart

  Construction

  • Simple squamous epithelium
  • Areolar connective tissue


  Serous membrane (Serosae)
• Definition

  • Line fibrous capsule surrounding joints
  • Line bursae
  • Line tendon sheaths
  • Provides a smooth surface and secrete a lubricating fluid
  • Cushion organs moving against each other during muscle activity

  Construction

  • Loose areolar connective tissue
  • No epithelial tissue


  Synovial membrane