Study Question Nine

• Q9. How are membranes related to connective tissues and the framework of the body?
• A membrane consists of an epithelial sheet with an underlying connective tissue layer
• Four types of epithelial membranes:

  • mucous
  • serous
  • cutaneous
  • synovial
• MUCOUS MEMBRANE forms a barrier that resist the entry of pathogens
• Epithelial surfaces of the mucosa are moist because they are lubricated by mucus or other glandular secretions or by fluids
• The areolar tissue component of a mucous membrane is called the lamina propria
• SEROUS MEMBRANE consists of a mesothelium supported by a thin layer of areolar connective tissue rich in blood and lymphatic vessels
• Three types of serous membrane:

  • pleura that lines the pleural cavities and covers the lung
  • peritoneum that lines the peritoneal cavity and covers surfaces of enclosed organs
  • pericardium lines the pericardial cavity and covers the heart
• The fluid formed on the surfaces of a serous membrane is called a transudate
• CUTANEOUS MEMBRANE, or the skin, covers the surface of the body.
• Cutaneous membrane consists of a keratinized stratified squamous epithelium and an underlying layer of areolar connective tissue that is reinforced by a layer of dense connective tissue
• Unlike serous and mucous membrane, the cutaneous membrane is thick, waterproof, dry
• SYNOVIAL MEMBRANES line a joint cavity
• Synovial membranes consist of areolar tissue covered by an incomplete superficial layer of squamous or cuboidal cells
• Synovial membrane differ from epithelial tissue because of:

  • no basement membrane
  • cellular layer incomplete with gaps
  • derive cells from macrophages and fibroblasts