Lecture #3 Flashcards
Name the special characteristics of epithelia and describe them
SCRAPS
- Specialized contacts: cells joined by special junctions
- Cellularity: cells separated by minimal extracellular material
- Regeneration: lost cells are quickly replaced by cell division
- Avascular, but innervated: epithelial cells receive nutrients from underlying connective tissue
- Polarity: cell regions of the apical surface differ from the basal surface
- Support by connective tissue
Name the structure that is a noncellular supporting sheet between epithelial tissue and the connective tissue deep to it
basal lamina
What are the functions of the basal lamina?
- acts as selective filter (determines which molecules from capillaries enter the epithelium)
- acts as scaffolding (along which regenerating epithelial tissues cells can migrate)
What forms the basement membrane?
- basal lamina
- reticular layers
Which epithelia consists of a single layer with flat cells containing disc-shaped nuclei?
- simple squamous epithelium
Which epithelia consists of a single layer of square-shaped cells with large, spherical central nuclei?
simple cuboidal epithelium
Which epithelia consists of a simple layer of rectangular cells with round nuclei?
simple columnar epithelium
Which epithelia has cells that originate at the basement membrane, but only tall cells reach the apical surface; nuclei lie at varying heights
pseudostratified columnar epithelium
Which epithelia contains deeper layers of cells can appear cuboidal or columnar and is the thickest epithelial tissue
stratified squamous epithelium
What are the two types of stratified squamous epithelium? Describe what they do.
- keratinized: on epidermis (surface cells are dead + full of keratin); contains protective protein keratin; waterproof
- nonkeratinized: forms moist lining of body openings
What is generally two layers of cube-shaped cells?
stratified cuboidal epithelium
Which epithelia is several layers where the basal cells are usually cuboidal and superficial cells are elongated?
stratified columnar epithelium
Which epithelia has characteristics of stratified cuboidal and stratified squamous? Superficial cells are dome-shaped when the bladder is relaxed, and squamous when full.
transitional epithelium
What is the function of simple squamous epithelium?
- passage of material by passive diffusion and filtration
- secretes lubricating substances in serosae
What is the function of simple cuboidal epithelium?
secretion and absorption
What is the function of simple columnar epithelium?
- secretion of mucus and absorption
- ciliated type propels mucus or reproductive cells by ciliary action
What is the function of psuedostratified columnar epithelium?
secretion and propulsion of mucus by cilia
What is the function of stratified squamous epithelium?
protects underlying tissue in areas subject to abrasion
What is the function of stratified cuboidal epithelium?
protection
What is the function of stratified columnar epithelium?
protection and secretion
What is the function of transitional epithelium?
permits distention of urinary organs when filled
Describe endocrine glands: Where does it secrete and what does it produce?
- ductless gland
- secrete directly into surrounding tissue fluid
- produces messenger molecules: hormones
What duct carries product of itself to the epithelial surface?
exocrine gland
Where is fibroblast found? What does it make?
- CT proper (loose and dense)
- makes protein subunits
What secretes the matrix in cartilage?
chondroblast
What secretes the matrix in bone?
osteoblasts
What fiber is the strongest and can resist tension?
collagen fiber
Which fiber bundles of special type of cartilage?
reticular fibers
Which fiber can recoil after stretching?
elastic fibers
Describe ground substance: What is it produced by? Texture? Function?
- produced by: primary cell type
- gel-like substance
- cushions and protects body structures
- holds tissue fluid
What makes up the extracellular matrix?
fibers + ground substance
What tissue has a gel-like matrix with all three fiber types and underlies epithelial tissue?
areolar connective tissue