Epithelial Tissue
-Lines inner passageways opening to surface -Protect -Avascular -Selective Permeability-Sensation- Secretion -Regenerate
SPECIALIZATION OF EPITHELIAL CELLS
1) Microvili absorb and secrete; urinary and digestive tract
2) Stereocilia inner ear and male reproductive tract
3) Ciliated Epithelium respiratory tract
CLASSIFICATIONS
1) Squamous
Simple Squamous Epithelium BV and heart; reduce friction; absorb and secrete
Stratifed Squamous Epithelium Skin; protect
2) Cuboidal
Simple Cuboidal Epithelium kidney tubules, ducts, thyroid glands; absorb and secrete
3) Columnar
Simple Columnar Epithelium stomach, intestinal tract, excretory ducts; more protect than cuboidal
Stratified Columnar Epithelium Pharynx, urethra, anus, epiglottis, mammary glands; RARE; columnar top
4) Pseudostratified Ciliated Columnar 2 types; respiratory tract
5) Transitional Epithelium Stretch extensively; renal pelvis, ureters, urinary bladder; cuboidal top
6) Glandular Epithelium Classified by Secretion, Structure, and Mechanism
EXOCRINE ENDOCRINE
1) Serous Gland salivary amylase enzyme - saliva 1) Hormones regulate activities
2) Mucous Gland Glycoprotein (mucins)+ H20 = mucus
3) Mixed Exocrine Gland Both Secretions
MECHANISMS OF SECRETION
1) Merocrine/Eccrine Secretions Exocytosis (send out); OWN duct; salivary gland
2) Apocrine Secretions During apical portion shedding; small duct joining other duct; mammary gland
3) Holocrine Secretions gland cell burts; sebaceous glands
