Epithelial Tissues

Table 8.1: Epithelial Tissues, Descriptions, Functions, and Representative Locations - Provides a comprehensive overview of various epithelial tissue types:- Simple Squamous Epithelium:

  • Description: Single thin layer; flattened cells.

  • Functions: Filtration; diffusion; osmosis; secretion.

  • Representative Locations: Air sacs (alveoli) of lungs; walls of capillaries; linings of blood vessels and ventral body cavity.

    • Simple Cuboidal Epithelium:

  • Description: Single layer; cube-shaped cells.

  • Functions: Secretion; absorption.

  • Representative Locations: Surface of ovaries; linings of kidney tubules; linings of ducts of certain glands.

    • Simple Columnar Epithelium:

  • Description: Single layer; elongated narrow cells; some ciliated.

  • Functions: Protection; secretion; absorption.

  • Representative Locations: Linings of uterus, stomach, gallbladder, and intestines.

    • Pseudostratified Columnar Epithelium:

  • Description: Single layer; elongated cells; some cells do not reach free surface; often ciliated.

  • Functions: Protection; secretion; movement of mucus and substances.

  • Representative Locations: Linings of respiratory passages.

    • Stratified Squamous Epithelium (Nonkeratinized):

  • Description: Many layers; surface cells flattened and remain alive.

  • Functions: Protection; resists abrasion.

  • Representative Locations: Linings of oral cavity, esophagus, vagina, and anal canal.

    • Stratified Squamous Epithelium (Keratinized):

  • Description: Many layers; surface cells dead and keratinized.

  • Functions: Protection; resists abrasion; retards water loss.

  • Representative Locations: Epidermis of skin.

    • Stratified Cuboidal Epithelium:

  • Description: 2 to 3 layers; cube-shaped cells.

  • Functions: Protection; secretion.

  • Representative Locations: Linings of larger ducts of mammary glands, sweat glands, salivary glands, and pancreas.

    • Stratified Columnar Epithelium:

  • Description: Superficial layer of elongated cells; basal layers of cube-shaped cells.

  • Functions: Protection; secretion.

  • Representative Locations: Part of the male urethra; parts of the pharynx.

    • Transitional Epithelium:

  • Description: Many layers; cube-shaped and elongated cells; thinner layers when stretched.

  • Functions: Distensibility; protection.

  • Representative Locations: Linings of urinary bladder and ureters and part of urethra.

    • Glandular Epithelium:

  • Description: Unicellular or multicellular.

  • Functions: Secretion.

  • Representative Locations: Salivary glands; sweat glands; endocrine glands.