EPITHELIAL TISSUE: Lines exterior of body, tracts, some glands, and openings to exterior
Epithelial tissue membranes contain epithelial cells
- Includes a mucosa supported lamina propria
FUNCTIONS OF EPITHELIA
• Protection against pathogens + toxins
• Fluid loss regulation
• Secretion, absorption, and excretion
CHARACTERISTICS OF EPITHELIA
• Contains little, if any, matrix
• Cells are linked by cell junctions
• Apical (lumenal) & basolateral surfaces
• Largely avascular – VESSELS DO NOT CROSS BASEMENT MEMRBANE
• Highly mitotic
ENDOTHELIUM IS A TYPE OF EPITHELIUM
GLANDULAR EPITHELIUM
• Generally exocrine
• Secretions may arise from single cells or glands
• Can be found in mucus, perspiration, saliva, milk, cerumen (ear wax)
3 types of glandular epithelium secretion
1. Merocrine – exocytosis of vesicle
a. Relatively common (some sweat glands)
2. Apocrine (decapitation) – apical portion of cell is extruded + released during secretion
a. Axillary sweat glands
3. Holocrine - autolysis of epithelial cell)
a. Sebaceous glands
Epithelial tissue membranes contain epithelial cells
- Includes a mucosa supported lamina propria
FUNCTIONS OF EPITHELIA
• Protection against pathogens + toxins
• Fluid loss regulation
• Secretion, absorption, and excretion
CHARACTERISTICS OF EPITHELIA
• Contains little, if any, matrix
• Cells are linked by cell junctions
• Apical (lumenal) & basolateral surfaces
• Largely avascular – VESSELS DO NOT CROSS BASEMENT MEMRBANE
• Highly mitotic
ENDOTHELIUM IS A TYPE OF EPITHELIUM
GLANDULAR EPITHELIUM
• Generally exocrine
• Secretions may arise from single cells or glands
• Can be found in mucus, perspiration, saliva, milk, cerumen (ear wax)
3 types of glandular epithelium secretion
1. Merocrine – exocytosis of vesicle
a. Relatively common (some sweat glands)
2. Apocrine (decapitation) – apical portion of cell is extruded + released during secretion
a. Axillary sweat glands
3. Holocrine - autolysis of epithelial cell)
a. Sebaceous glands
