Cell Biology II Flashcards
What are tissues?
groups of cells that have similar structure and perform similar functions
Four types of tissues?
Epithelium
Mesenchymal OR connective tissue
Muscle
Nervous tissue
Functions of epithelia? Examples for each?
Protection (epidermis)
Absorption/Secretion (GI tract)
Selective diffusion (walls of capillaries)
Glandular secretion (sebaceous glands)
Providing sensation (retina)
What is epithelia? Accompanied by?
tissues that line or cover surfaces in the body, connective tissue (often)
Epithelia vascular or avascular? Explanation?
Avascular; have high cell turnover and connective tissue that IS vascular
What is polarity?
fixed segments of a cells border different from one another
What is a lumen?
space contained within a tube or sphere
What is the apical border?
Border facing the lumen
What is the lateral border?
surface facing or attached to adjacent cells in the tissue
What is the basal border?
surface adjacent to the underlying connective tissue matrix
Epithelia layer definitions? One? Two or more?
Simple
Stratified
Shape of epithelial cell?
Flat?
Cube-shaped?
Tall and skinny?
Squamous
Cuboidal
Columnar
Where are simple squamous epithelium found? Example?
Where simple diffusion is required ex. walls of capillaries THINK: little cytoplasm so little room for organelles
Where do simple cuboidal epithelium cells live? Example?
Line secretory surfaces and ducts that conduct secretions; ducts of small exocrine glands
Simple columnar epithelium line? Example?
Secretory and/or absorptive surfaces; lining of the stomach THINK: Most cytoplasm most # of organelles
Where are stratified squamous cells found? Trend amongst layers? Example? Apical layers are sometimes _____?
Where a lot of abrasion occurs; basal is thicker than apical; epidermis; keratinized
Functions of stratified cuboidal cells? Example? Commonality?
Protects against chemical abrasion, contributes to secretion; mammary glands, RARE
Where are transitional epithelium found? Example? Appearance?
Where stretching occurs; lining of bladder; apical layer is scalloped
Functions of stratified columnar cells? Example? Commonality?
Secretion and protection; male urethra; VERY RARE
Where are pseudostratified columnar epithelium found? Example? Why are the “pseudo”?
mucus secreting cells; trachea; basilar surface of EVERY cell touches basement membrane
What are lateral modifications of the epithelia?
Desmosomes and gap or tight junctions
Relationship between basilar surface and basement membrane?
ALWAYS fused
What is the basement membrane a barrier against? Important for? Can act as ____.
malignant cells, angiogenesis (production of blood cells), filtration membrane
Three apical modifications?
Microvilli, cilia, stereocilia
Microvilli arrangement and function?
parallel (like a brush), contribute to absorption
Difference between cilia and microvilli appearance?
Cilia are wider in diameter
Function of cilia?
VERY motile, move mucus or other lumenal secretions
Appearance and function of stereocilia?
Very long microvilli; absorption
Are stereocilia motile?
NO
