Epithelium and Glands

Question 1

characteristics of epithelium

Answer 1

continuous sheets
rest on basement membrane
junctions
polarized-have a top and a bottom
surface modifications-cilia, microvilli, etc
avascular-epithelium itself is not vascularized, adjacet connective tissue is

Question 2

epithelium functions

Answer 2

protection/barrier-skin and organ coverings
absorption and secretion-dig system
gas exchange-endothelium
removal of particulate-respiratory system
filtration-kidney

Question 3

Apical Surface Modifications

Answer 3

faces extracellularly

microvilli, cilia, stereocilia

Question 4

stereocilia

Answer 4

have actin cytokeleton, not microtubule
thus are NOT motile
absorptive
epididymis and vas deferens (very long) and ear

Question 5

microvilli

Answer 5

actin cytoskeleton
inc absorption
not motile
insert into a mesh of actin (terminal web) –> terminal bar=terminal web + junctional complex (makes a visible line under microvilli)

Question 6

cilia

Answer 6

microtubule cytoskeleton
helpful in motility
more discrete terminal bar than microvilli

Question 7

Basal Surface Modifications

Answer 7

basal infoldings of microvilli

contain mitochondria

Question 8

simple squamous epithelium

Answer 8

made to w/stand abrasion

line lumen of cavities: pleura, peritoneal, and pericardial

Question 9

simple cuboidal

Answer 9

for transport, synthesis and secretions
line small ducts, kidney and thyroid follicles
line passageways for exocrine secretions
taller cuboidal cells provide a little protection and support

Question 10

simple columnar epithelium

Answer 10

multiple functions: absorption and secretion
line digestive tract and uterine tube

SI simple columnar cells have microvilli for absorption and goblet cells for secretion

in uterine tube have cilia

Question 11

brush border

Answer 11

microvilli give linear appearance on top of cell

Question 12

stratified keratinized squamous epithelium

Answer 12

skin

upper layers are dead

Question 13

stratified nonkeratinized squamous epithelium

Answer 13

moist areas

upper layer alive

Question 14

stratified cuboidal

Answer 14

large excretory ducts

protection

Question 15

pseudostratified

Answer 15

all cells touch basal layer, not all reach the top
respiratory epithelium has ciliated columnar cells and goblet cells, and sensory and secretion cells
epididymis has stereociliated columnar cells and shorter basal cells

Question 16

transitional epithelium

Answer 16

in urinary system
can stretch, stretched layers are more flat
when relaxed top layer is domed

Question 17

gland classifications

Answer 17

simple (singular duct)-tubular or coiled, or branched tubular or acinar
compound (stem branched off, more than one duct)-tubular, acinar, or tubuloacinar

Question 18

Exocrine glands

Answer 18

lobule-contains parenchyma, made of secretory units
lobe contains multiple lobules
blood vessels run between lobules=interlobular
blood vessels run into lobules to collect secretions=intralobular

Question 19

serous demilunes

Answer 19

one acini-mucous cell associated w/ a serous cell

Question 20

apocrine

Answer 20

loss of cytoplasm and apical cell membrane

mammary gland

Question 21

holocrine

Answer 21

only in sebaceous skin glands

accumulates lipids and whole cell is secretion

Question 22

merocrine

Answer 22

exocytosis of secretory vesicles
no loss of cell membrane
salivary glands, and most all others

Question 23

4 basic tissue types

Answer 23

1) epithelium
2) connective tissue
3) muscle
4) nervous tissue