EPITHELIUM Flashcards
this tissue consists of sheets of cells that cover the external surfaces of the body, line the internal cavities and the organs, form various organs and glands, and line their ducts.
Epithelial Tissue
Epithelium is _____ by the blood vessels and is therefore ________
not supplied, avascular
two functional types of epithelium:
lining epithelium and glandular epithelium
Absorption occurs via?
endocytosis or pinocytosis
Secretion of various molecules (e.g., hormones, mucus, proteins) occurs by?
exocytosis
Protection from abrasion and injury is provided by
epidermis, the epithelial layer of the skin.
a specialized, feltlike sheet of extracellular material referred to as the ?
basement membrane
major transmembrane link to proteins of Zonula Occludens
occludins, claudins, ZO proteins
major transmembrane link to proteins of Zonula Adherens
E-cadherin, catenin complexes
major transmembrane link to proteins of Macula Adherens
Cadherin family proteins (desmogleins, desmocollin)
major transmembrane link to proteins of Hemidesmosome
Integrin
major transmembrane link to proteins of Nexus
Connexin
cytoskeletal components of Zonula Occludens
Actin filaments
cytoskeletal components of Zonula Adherens
Actin filaments
cytoskeletal components of Macula Adherens
intermediate filaments (keratin)
cytoskeletal components of Hemidesmosome
Intermediate filaments
cytoskeletal components of Nexus
none
This junction seals adjacent sells to one another, controlling passage of molecules between them; separates basolateral and apical domains
Tight Junction (Zonula Occludens)
This junction provides points linking the cytoskeletons of adjacent cells; strengthens and stabilizes nearby tight junctions
Adherent Junction (Zonula adherens)
This junction provides points of strong intermediate filament coupling between adjacent cells, strengthening the tissue.
Macula Adherens (desmosome)
The Hemidesmosome anchors what?
cytoskeleton to the basal lamina
The Gap Junction or Nexus allows direct transfer of what molecules?
small molecules and ions from one cell to another
_______ are motile structures found on certain cells in the uterine tubes, uterus, efferent ducts in the testes, and conducting tubes of the respiratory system.
Cilia
They are small, nonmotile projections that cover the surfaces of all absorptive cells in the small intestine and the proximal convoluted tubules in the kidney.
Microvilli
What are Stereocilia?
They are long, nonmotile, branched microvilli that line the cell surfaces in the epididymis and vas deferens.
Where can Simple Squamous Epithelium be found? (location)
Location: Endothelium (lining of blood vessels), Mesothelium (lining of peritoneum and pleura)
Location of the Simple Cuboidal Epithelium
Lining of distal tubule in kidney and ducts in some glands, surface of ovary
What epithelium is described?
Location: Lining of intestine, stomach, and excretory ducts in some glands
Simple Columnar Epithelium
What epithelium is being described?
Location: Lining of trachea, primary bronchi, nasal cavity, and excretory ducts in parotid gland
Pseudostratified Columnar Epithelium
What epithelium is being described?
Location: Lining of esophagus, vagina, mouth, and true vocal cords (nonkeratinized); Epidermis of skin (keratinized)
Stratified Squamous Epithelium
What epithelium is being described?
Location: Lining of ducts in sweat glands; Lining of large excretory ducts in some glands and cavernous urethra
Stratified Cuboidal and Columnar Epithelium
What epithelium is being described?
Location: Lining of minor and major calyces, pelvis, ureters, and the bladder of the urinary system
Transitional Epithelium
