Epithelium

What does ectoderm cover?

skin

What does mesoderm line?

lines blood vessels

What is endoderm?

gut lining

What does the epithelium rest on?

basal lamina

What does the epithelium form basement membrane in conjunction with?

reticular lamina

What does epithelium function as?

selective barrier

does epithelia display polarity?

yes

What is the apical surface of epithelium?

the free surface with microvilli/cilia

What is the lateral domain in the epithelium?

in contact with adjacent cells

What is the basal domain in the epithelium?

in contact with basement membrane

What does microvilli do?

increase surface area

Where is microvilli seen?

in absorptive surfaces (gi tract, kidkney tubules)

What does cilia do?

promote movement of surface material

Where is cilia seen?

respiratory tract, oviduct

What is a single cilia called?

flagellum

What is stereocilia?

long microvilli lining luminal surface of columnar cells

What do tight junctions/zona occludens do?

seals epithelial surface

What are zona adherens?

belt like around cell

What are macula adherens in desmosomes?

focal area

What happens with hemidesmosomes in desmosomes?

Cell attaches to basal lamina

What are gap junctions

pores for intercellular communication

Where are gap junctions seen?

epithelial layers

Which domain are the junctions in?

Lateral domain

What does the basement membrane (basal domain) act as for epithelial cells?

Anchor point

What are the main components of basal lamina secreted by?

epithelial cells

What are reticular lmina produced by?

connective tissue fibroblasts

What are the functions of the epithelium?

protection, absorption, secretion, excretion, may display selective permeability

What shape of cell is mesothelium and endothelium?

simple squamous

What surfaces are simple squamous cells usually on

moist inner surfaces

What are simple cuboidal cells usually associated with?

secretion and/or absorption

What cell shape are kidney tubules?

simple cuboidal

Which cell shape will all cells reach basal lamina but not all cells reach the free surface?

pseudo-stratified columnar

What is the primary function of stratified squamous cells?

protection

Where are non-keratinized stratified squamous cells seen?

wet surfaces (mouth)

Where are keratinized stratified squamous cells seen?

dry surfaces (skin)

Do surface cells non-keratinized stratified squamous cells retain their nuclei?

yes

Do surface cells on keratinized stratified squamous cells retain their nuclei?

no

Where do you see transitional epithelium?

urinary system (bladder, urethra)

What are glandular epithelium cells specialized for?

secretion

Are goblet cells unicellular or multicellular glands?

unicellular

What are examples of multicellular glands?

endocrine and exocrine glands

are endocrine glands ductless or do they have ducts?

ductless

What do endocrine glands produce?

hormones

Do exocrine glands have ducts or are they ductless?

They have ducts

What is merocrine mode of secretion?

exocytosis

What is apocrine mode of secretion?

part of cell is pinched off

What is holocrine mode of secretion?

whole cell is extruded

What is cytocrine mode of secretion?

melanin transfer from cell to hair

What are myoepithelial cells?

sweat and mammary glands