INTEGUMENTARY SYSTEM

• Tissues


  • Epithelial
  • Connective
  • Nervous
  • Muscle
• Tissues


  Groups of cells that perform a special function
• Four main types of tissues

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Embryonic origin of tissues

  1. First embryonic cells differentiate into any type of cell

  2. Three major cell lineages established within the embryo

  3. Each germ layer identified by its relative position (ectoderm, mesoderm, endoderm)
• Epithelial tissues


  Sheets of cells that cover exterior surfaces, line internal cavities and passageways, and form certain glands

  
• Functions of epithelial tissues

  • Protective covering
  • Reduction of friction
  • Absorption
  • Synthesis and secretion of various proteins
  • Excretion
  • Sensation
  • Thermoregulation
• Types of epithelial cells

  • Squamous
  • Cuboidal
  • Columnar
• Types of epithelial tissue

  • Simple
  • Stratified
  • Transitional
  • Pseudostratified
• Endocrine gland cells


  Form ductless glands that secrete substances (hormones)
• Exocrine gland cells


  Secrete substances directly into ducts
• Stratified squamous epithelium is not suitable for lining the walls of the intestines
• Cigarette smoking has detrimental effects on the lining epithelium of the respiratory tract
• Connective tissues


  Bind the cells and organs of the body together and function in the protection, support, and integration of all parts of the body
• Types of connective tissue

  • Adipose
  • Areolar
  • Reticular
  • Dense Connective
  • Dense Fibrous
  • Supportive
  • Vascular

  
• Fibroblasts


  Actively dividing and secreting ground substance
• Chondroblasts and osteoblasts


  For cartilage and bone, respectively
• Ground substance


  Secreted by fibroblasts, made of proteoglycan which is a combination of polysaccharides and proteins
• Adipose tissue


  • Stores lipid (fat), acts as filler tissue, cushions, supports, and insulates the body
• Areolar tissue


  • Semifluid matrix, contains fibroblasts, macrophages, plasma cells, mast cells and white blood cells, collagen and elastin fibers

  
• Reticular tissue


  • A mesh-like, supportive framework for soft organs
• Types of dense connective tissue


  • Regular
  • Irregular

  
• Examples of dense fibrous tissue


  • Ligaments
  • Tendons
  • Aponeuroses
  • Fasciae

  
• Dense irregular connective tissue


  • Arrangement of fibers lacks uniformity, gives greater strength in all directions and less strength in any one particular direction
• Dense elastic tissue


  • Contains elastin fibers and collagen fibers, allows the tissue to return to its original length after stretching
• Types of supportive connective tissue


  • Osseous (bone)
  • Cartilage (hyaline, fibrocartilage, elastic)

  
• Vascular (liquid blood) tissue


  Blood (plasma and cellular components), lymph (contains water, glucose, proteins, fats, salts and other tissue components)
• Tissues


  • Epithelial
  • Connective
  • Nervous
  • Muscle
• Tissues


  Groups of cells that perform a special function
• Four main types of tissues

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Embryonic origin of tissues

  1. First embryonic cells differentiate into any type of cell

  2. Three major cell lineages established within the embryo

  3. Each germ layer identified by its relative position (ectoderm, mesoderm, endoderm)
• Epithelial tissues


  Sheets of cells that cover exterior surfaces, line internal cavities and passageways, and form certain glands

  
• Functions of epithelial tissues

  • Protective covering
  • Reduction of friction
  • Absorption
  • Synthesis and secretion of various proteins
  • Excretion
  • Sensation
  • Thermoregulation
• Types of epithelial cells

  • Squamous
  • Cuboidal
  • Columnar
• Types of epithelial tissue

  • Simple
  • Stratified
  • Transitional
  • Pseudostratified
• Endocrine gland cells


  Form ductless glands that secrete substances (hormones)
• Exocrine gland cells


  Secrete substances directly into ducts
• Stratified squamous epithelium is not suitable for lining the walls of the intestines
• Cigarette smoking has detrimental effects on the lining epithelium of the respiratory tract
• Connective tissues


  Bind the cells and organs of the body together and function in the protection, support, and integration of all parts of the body
• Types of connective tissue

  • Adipose
  • Areolar
  • Reticular
  • Dense Connective
  • Dense Fibrous
  • Supportive
  • Vascular