Epithelial Tissue Flashcards
Epithelial Tissue
- many cells tightly packed together ~ little to no extracellular matrix
- densely packed sheets of cells
- Many cell junctions
- Attach to basement membrane
- Avascular —no blood vessels - HAS a nerve supply
- Mitosis occurs frequently
Apical (free) surface
faces outside world
Lumen
hollow space (food , water)
Basal surface
Bottom
Basement Membrane
basal+reticular lamina ; formed by underlining epithelial + connective tissue
Simple
1 layer of cells
Pseudostratified
falsely; not every cell reaches apical surface, nucleus at different levels
Stratified
2+ rows of cells
Squamous
Flat “floor tiles”
Cuboidal
Squared
Columnar
Long columns
Transitional
Functional classification, shape changes based on function
Simple squamous function
• Filtration • Diffusion • Secretion
Simple squamous location
• Cardiovascular + Lymphatic
• Serous membranes
• Alveoli
• Kidneys
• inner eardrum
Simple cuboidal function
• Secretion • Absorption
Simple cuboidal location
• Ovary
• Eye Lens
• Eye Retina
• Kidney tubules
• Thyroid gland
• Pancreas
Simple cilliated columnar function
• Cilia —moves
mucus toward throat away from
lung; coughed up/ swallowed/spit out
• move oocytes from ovaries —> uterus
Simple non-cilliated columnar function
• Absorption • Secretion
PSUEDOSTRATISFIED CILLIATED COLUMNAR function
• Goblet cells Secrete mucus • Cilia sweeps away mucus
PSUEDOSTRATISFIED CILLIATED COLUMNAR location
Respiratory tract
PSUEDOSTRATISFIED NON-CILLIATED COLUMNAR function
• Absorption • Secretion
PSUEDOSTRATISFIED NON-CILLIATED COLUMNAR location
• epididymis
• gland ducts
• male urethra
Stratified squamous function
Protection
Stratified squamous location
- Keratinized —
• intracellular protein - Non-keratinized —
• deep ; moistened by
mucus
Stratified cuboidal function
• Protection • Secretion • Absorption
Stratified cuboidal location
• Sweat gland
• esophageal glands
• male urethra
Stratified columnar function
• Protection • Secretion
Stratified columnar location
• urethra
• esophageal glands
• anal mucous membrane
• conjunctiva of eye
Translational function
• organs stretch
• maintain lining
• Holds varying fluid without rupturing
Translational location
• urinary bladder
• ureters
• urethra
Gland
a single cell or a mass of epithelial cells adapted for secretion
Unicellular
Single cell
Multicellular
Many cells
Endocrine gland secretion
enter interstitial fluid + diffuse into bloodstream
Exocrine gland secretion
enter ducts ; empty onto surface of epithelium
Unbranched duct
Simple
Branched duct
Compound
Secretary portion
Tubed shaped
Tubular
Secretary portion
Round shaped
Aciner
Secretary portion
Round + tube shape
Tubuloacinar
Merocrine glands
released from cell in secretory vesicles via exocytosis
Apocrine glands
portion of the cell pinches off by exocytosis
Holocrine glands
As cell matures, it ruptures and becomes secretory product