SM48_EpithelialHistology

Question 1

What germ layer is the epithelial tissue derived from?

Answer 1

TRICK QUESTION! all threee of em germ layers bish

Question 2

Three common traits of all epithelial tissue

Answer 2

Anchored to a basement membrane (aka basal lamina), tightly connected to one another at lateral surface via specialized junctional complexes, avascular

Question 3

because epithelial cells are __________, they rely on diffusion of nutrients and gases from the vasculature in the adjacent connective tissue

Answer 3

avascular

Question 4

All the stuff that epithelial tissue comprises

Answer 4

exterior of body, outer surface of most internal organs, lining of body cavities, tubes, and ducts (cardiovascular system!), and glands

Question 5

Three types of glands

Answer 5

exocrine - secretes products onto surfaces or into a lumen via epithelial duct

endocrine - secretes hormones into bloodstream

paracrine - secretions affect adjacent cells

Question 6

Keratinization is a property of only _____ ______ epithelia

Answer 6

stratified squamous

Question 7

Properties of single squamous epithelium (location in body)

Answer 7

SINGLE LAYER; FLAT (squamous) cells; forms continuous surface

Parietal layer of bowman’s capsule
Endothelium - lines blood vessels
Mesothelium - lines body cavities
lung alveolar walls

Question 8

Properties of simple cuboidal epithelium (location in body)

Answer 8

SINGLE LAYER; SQUARE (cuboidal) cells; nucleus often appear circular in cross sectio

Apical surface usually lines lumens of ducts and tubules``
specifically, renal tubules, thyroid follicles, and other glands

Question 9

Simple columnar epithelial

Answer 9

SINGLE LAYER; RECTANGULAR (columnar)

Absorptive surfaces (e.g. small intestine and bronchioles)

Question 10

Pseduostratified epithelium

Answer 10

SINGLE LAYER (appears stratified, but actually every cell touches the basement membrane); CILIATED COLUMNAR EPITHELIAL CELLS (nuclei at diff levels)

Found in: larger airways of respiratory system (trachea), and epididymis

Question 11

Stratified squamous epithelium

Answer 11

STRATIFIED (multiple layers); KERATINIZED OR NON-KERATINIZED. Keratinized - found at surfaces exposed to dry conditions

Basal cells of this type of tissue are progenitor cells that divide and give rise to differentiated cells

Non-keratinized found in: Covering internal body surfaces that are moist (e.g. oral cavity, esophagus, vagina, anal canal)

keratinized: skin

Question 12

Icthyosis

Answer 12

group of disorders of keratinization characterized by excess keratinization and scale-like skin appearance

Question 13

Transitional epithelium

Answer 13

STRATIFIED;

Shape of lumen lining cells - dome-shaped cuboidal at relaxed state; flattens out (squamous-like) in stretched state

Found in: urinary tract (designed to be extensible as bladder fills w urine)

Question 14

Apical membrane (aka luminal surface) – type of specializations

Answer 14

Microvilli (aka brush border, actin based), Cilia (microtubule based), Stereocilia (contains actin filaments in core)

Question 15

Types of junctional complexes in lateral domain of epithelial cells

Answer 15

Tight junctions (zonula occludens), Adherens junctions (zonula adherens), desmosome (macula adherens), gap junctions

Hint: occludens vs adherens hints are purpose of complexes

Question 16

subunit of gap junction

Answer 16

connexion molecule

Question 17

adhesion molecules involved in adherens junctions (and desmosomes!)

Answer 17

cadherins

Question 18

Autoantibodies of pemphigus (skin conditions) induce desmosome disruption, which leads to _____

Answer 18

cell-cell separation; blistering within epithelium

Question 19

Membrane structure responsible for contact between basal domain and basement membrane

Answer 19

hemidesmosome

Question 20

Hemidesmosomes serve as a cell surface attachment site for ____ and are connected to a matrix of extracellular ____ in the basal lamina

Answer 20

keratin intermediate filaments; Type IV collagen aka laminin

Question 21

Bullous Pemphigold

Answer 21

autoantibodies against hemidesmosomal proteins –> separation of epithelium of skin from underlying connective tissue (skin blistering)

Question 22

Proteins composing tight junctions

Answer 22

claudins, occludins

Question 23

Tight junction (other name)

Answer 23

Zonula occludens

Question 24

Adherens Junction (other name)

Answer 24

Zonula adherens

Question 25

Desmosome (other name)

Answer 25

macula adherens