Epithelial Tissue Flashcards
What are the 4 types of tissue
connective, epithelial, muscle, nervous
Where is ectoderm
epithelium on external surfaces
where is mesothelium
epithelium lining internal cavities and vessels
where is endothelium
epithelium lining tubes (vascular and lymph system)
Are epithelial cells generally non-polarized? Vascular? Mitotic?
POlarized (apical and basal regions have different fxns), non-vascular, high mitotic activity (replaces quickly)
Is there generally a lot of extracellular space
No, generally a little
Cilia v Microvilli
Cilia (9+2 microtubules) for movement and microvilli for surface area(kidney/SI)
What are the three shapes of epithelial cells (or outer layer of stratified)
squamous: width greater than height
cubodial: width, depth, height about the same
columnar: height bigger than width
Where do you find simple squamous cells? fxn
rapid movement across epithelium, extremely flattened including nuclei
in lining of body caivities (mesothelium), renal capsul (bowmans) e, resp space of lung
Where do you find simple cubodial cells? fxn
ion pumps, secretory cells, function in secretion and absorption
- have large spherical nuclei
located in kidney tubules, ducts and secretory portions of glands and ovary surface
simple columnar fxn? where
secretive or absoprtive
SI, Colo, stomach lining, gallbladder
Function stratified squamous cells?
for protection
- non keratinized for wet surfaces
- keratinized for dried surfaces (epidermis)
Where do you find stratified cubodial? fxn
very rare in ducts of sweat glands, usually 2-3 layers of cells
Where do you find stratified columnar cells?
rare, found at jxn between stratified squamous and simple columnar. are aof male urethra, conjuctiva of the eye, regions of male urethra
where do you find pseduostratified epithelial cells
trachea, bronchi and epidymis
for secretion and absoprtion
