body tissues

• Anatomy and Physiology


  A branch of anatomy that studies the structure of cells, tissues and their relations
• 4 basic types of tissues

  • Epithelial tissue
  • Connective tissue
  • Muscle tissue
  • Nerve tissue
• Histology


  The study of the microscopic structure of cells and tissues
• Epithelial tissue


  • Covers surfaces because cells are in contact
  • Lines hollow organs, cavities and ducts
  • Forms glands when cells sink under the surface
• Connective tissue


  • Supports and binds structures together
  • Stores energy as fat
  • Provides immunity to disease
• Muscle tissue


  • Cells shorten in length producing movement
• Nerve tissue


  • Cells that conduct electrical signals
  • Detects changes inside and outside the body
  • Responds with nerve impulses
• Types of epithelial tissue

  • Covering and lining epithelium
  • Glandular epithelium

  
• Types of covering and lining epithelium

  • Simple squamous
  • Simple cuboidal
  • Simple columnar
  • Pseudostratified columnar
  • Stratified squamous
  • Stratified cuboidal
  • Stratified columnar
  • Transitional

  
• Covering and lining epithelium

  • Epidermis of skin
  • Lining of blood vessels and ducts
  • Lining respiratory, reproductive, urinary & GI tract

  
• Glandular epithelium


  • Secreting portion of glands
• Simple epithelial tissue


  Single layer of cells
• Stratified epithelial tissue


  Multiple layers of cells
• Simple squamous epithelium


  • Line air sacs and vessels
• Simple cuboidal epithelium


  • Line kidney tubules
  • Cover ovaries
  • Line ducts of some glands
• Simple columnar epithelium


  • Line uterus, stomach and intestines
• Pseudostratified columnar epithelium


  • Line respiratory tract
• Stratified squamous epithelium


  • Outer layer of skin
• Stratified cuboidal epithelium


  • Line ducts of mammary glands, sweat glands, salivary glands, and the pancreas

  
• Stratified columnar epithelium


  • Line part of male urethra and part of pharynx
• Transitional epithelium


  • Lines urinary tract
• Glandular epithelium


  Cells that are specialized to produce and secrete substances
• Types of glandular epithelium

  • Endocrine glands
  • Exocrine glands
• Endocrine glands


  Lack ducts and secrete hormones directly into the blood
• Exocrine glands


  Have ducts and secrete their content by the ducts into the epithelial surface
• Connective tissue


  • Binds structures, provides support and protection
  • Stores fat, and produce blood cells
  • Forms part of the immune system which protects against infections
  • Helps repair tissue damage
• Components of connective tissue

  • Cells
  • Extracellular matrix
  • Blood vessels

  
• Connective tissue cell types

  • Fibroblasts
  • Macrophages
  • Mast cells

  
• Fibroblasts


  The most common cells in the connective tissue, large star-shaped cells that produce fibers in the extracellular matrix
• Macrophages

  Immune cells that phagocyte damaged and old cells and destroy pathogens, play a role in tissue repair
• Mast cells


  Cells that play a major role in the inflammatory process, release heparin and histamine
• Connective tissue fibers


  • Collagen fibers
  • Elastic fibers
  • Reticular fibers
• Collagen fibers


  Thick fibers composed of collagen that give the tissue strength and hold structures together
• Elastic fibers


  Bundles of microfibrils embedded in elastin that give the tissue elasticity
• Reticular fibers


  Very thin collagen fibers that are highly branched and form supportive networks
• Types of dense connective tissue

  • Dense regular
  • Dense irregular

  
• Dense regular connective tissue


  Cells and fibers are compactly arranged with a regular pattern, e.g. tendons and ligaments

  
• Dense irregular connective tissue


  Cells and fibers are compactly arranged with an irregular pattern, e.g. skin

  
• Elastic connective tissue


  • Consists of fibroblasts and densely compacted parallel bundles of elastic fibers with some collagen fibers, found in attachments between bones and walls of large arteries, airways, and heart
• Areolar connective tissue


  • Mainly fibroblasts in a fluid to gel-like matrix with collagen and elastic fibers, nourishes nearby epithelial cells, found under epithelia and under the skin