Lesson 3- Epithelial Tissues

• Epithelial tissues


  • Cover external body surfaces
  • Provide lining of the internal surfaces
  • Cells are arranged very closely with little intercellular substance between
  • Arranged as sheets covering or lining surfaces as masses of cells as in glands
• Categories of epithelial tissues


  • Simple epithelium
  • Stratified epithelium
  • Glandular or pyramidal epithelium
• Simple epithelium


  • Composed on one layer of cells all attached to the basement membrane
• Types of simple epithelium

  • Simple squamous epithelium
  • Simple cuboidal epithelium
  • Simple columnar epithelium
  • Pseudostratified columnar epithelium
• Goblet cell


  • Column-shaped cell found in the respiratory and intestinal tracts
  • Secretes the main component of mucus
• Stratified epithelium


  • Composed of more than one layer of cells
  • Only the basal cells are attached to the basement membrane
• Types of stratified epithelium

  • Stratified squamous epithelium (keratinized and non-keratinized)
  • Stratified cuboidal epithelium
  • Stratified columnar epithelium
  • Transitional epithelium
• Glandular or pyramidal epithelium


  • Serous glandular epithelium
  • Mucous glandular epithelium
  • Mixed glandular epithelium
• Mixed glandular epithelium


  • Submandibular salivary gland - mixed gland containing cells that produce both serous and mucous secretions
• Stratified squamous epithelium

  Keratinized type - epidermis of the skin

  Non-keratinized type - opening of the mouth, esophagus and vagina
• Stratified cuboidal epithelium - sweat gland ducts
• Stratified columnar epithelium - male urethra, conjunctiva, excretory ducts
• Transitional epithelium - excretory passage of urinary tract (ureter, urinary bladder and urethra)
• Serous glandular epithelium pancreas, parotid glands
• Mucous glandular epithelium - sublingual glands
• Mixed glandular epithelium - submaxillary glands
• Simple columnar epithelium - stomach, small intestines, large intestines, gallbladder, bile ducts, uterus, fallopian tube, epididymis, vas deferens, seminal vesicles, prostate gland, bronchioles, trachea, esophagus, salivary glands
• Simple cuboidal epithelium - renal tubules, thyroid follicles, ovarian follicle cells, endocrine cells of pancreas
• Simple squamous epithelium - lining of blood vessels, heart chambers, pericardium, pleurae, peritoneum, alveoli of lungs, glomerulus of kidney, synovial membrane
• Pseudostratified ciliated columnar epithelium - respiratory tract (trachea, bronchia)