Tissues — Epithelium

Question 1

epithelial characteristics

Answer 1

free surface, closely aggregated cells, avascular

Question 2

domains

Answer 2

apical, lateral, basal

Question 3

surface specialization of apical

Answer 3

microvilli, sterocilia, cilia

Question 4

microvilli

Answer 4

function to increase surface area; contains acting, actin-binding proteins (fibrin and fascin), lateral anchoring proteins (minimyosin), amorphous apex (villin)

Question 5

microvilli locations

Answer 5

GI tract and kidneys

Question 6

stereocilia

Answer 6

function to increase surface area; long microvilli

Question 7

stereocilia locations

Answer 7

epididymis (absorption) and each cochlea (sensory receptors)

Question 8

cilia

Answer 8

aids in movement; transports materials along surface; core is axoneme: 9+2 microtubules, basal body 9+0 triplets lacking central pair

Question 9

cilia locations

Answer 9

respiratory tract and oviduct

Question 10

cell junctions (lateral domain)

Answer 10

tight, anchoring, communicating (gap)

Question 11

tight junctions—zonula occludens

Answer 11

belt-like junction; seal or zipper; virtually impermeable; prevents diffusion blocking paracellular pathway; occudens and claudins are the two main proteins

Question 12

zonula occludens locations

Answer 12

stomach (cells with secretory role) and kidney (cells with absorptive role)

Question 13

anchoring junctions—zonula adherens

Answer 13

connects actin filaments of two cells; contains actin-binding proteins, peripheral protein catenin which is Ca2+ dependent, and transmembrane protein cadherin

Question 14

anchoring junctions—madula adherens

Answer 14

connects intermediate filaments of two cells; mechanical strength; intracellular plaque; contains transmembrane protein cadherin

Question 15

madula adheren locations

Answer 15

skin and muscle

Question 16

communicating (gap) junction

Answer 16

channel; 2 connexons each with 6 protein subunits called connexions; transport of small ions and molecules occurs; “puzzle pieces”

Question 17

gap junction locations

Answer 17

epithelia, cardiac and smooth muscle, embryonic tissues

Question 18

cell junctions (basal domain)

Answer 18

focal adhesions and hemidesmosomes

Question 19

focal adhesions

Answer 19

connects actin cytoskeleton to extracellular matrix; actin-binding proteins, peripheral protein (talin), transmembrane protein (integrin which is Ca2+ independent)

Question 20

hemidesmosome

Answer 20

connects intermediate filaments cytoskeleton to extracellular matrix; intracellular plaque; transmembrane protein (integrin)

Question 21

epithelium classification (# layers, shape, surface modification)

Answer 21

simple means single layer; stratified means more than one layer; pseudostratified is unorganized

squamous means flat; cuboidal means length and width are equivalent; columnar means column

surface modifications meaning they can be ciliated or non-ciliated

Question 22

simple squamous epithelium

Answer 22

lining of vascular system, lining of body cavities, kidneys (bowman’s capsule), lung (respiratory spaces)

function as a barrier and in diffusion (O2, CO2)

Question 23

simple cuboidal epithelium

Answer 23

kidney (tubules), germinal epithelium of ovaries, thyroid follicles, various ducts ( glands)

function as a barrier, in secretion (thyroid), absorption (kidneys)

Question 24

simple columnar epithelium

Answer 24

GI tract and gallbladder (non-ciliated), oviduct (ciliated type)

functions in absorption, secretion, lubrication, and transport

Question 25

pseudostratified columnar epithelium (ciliated and non-ciliated)

Answer 25

ciliated: trachea and bronchi; function in protection and movement (mucus) non-ciliated: epididymis (absorption) and prostate ***stereocilia

Question 26

stratified squamous epithelium

Answer 26

keratinized (skin, epidermis, contains keratin, dead) and non-keratinized (oral cavity, esophagus, vagina) functions as a barrier and protection

Question 27

stratified cuboidal epithelium

Answer 27

sweat gland ducts and some exocrine glands

Question 28

stratified columnar epithelium

Answer 28

large ducts of glands, parotid salivary, submandibular

Question 29

transitional epithelium (urothelium)

Answer 29

urinary system, ureter, bladder, kidneys (pelvis and calyces) functions as a barrier and protection

Question 30

glandular epithelium

Answer 30

formed as a result of epithelial tissue invagination

Question 31

exocrine glands — secretion methods

Answer 31

holocrine, apocrine, merocrine

Question 32

holocrine

Answer 32

cell destruction (apoptosis), whole cell content is released, cell sacrifices itself to deliver product ex. sebaceous gland

Question 33

apocrine

Answer 33

apical cytoplasm pinching, releasing of vesicles ex. mammary glands

Question 34

merocrine

Answer 34

exocytosis; doesn't sacrifice anything; most common; 3 types—serous, mucous, mixed ex. goblet cells, pancreas

Question 35

merocrine — serous

Answer 35

product thin, watery, protein-rich secretion; euchromatic nucleus (active cell), dark secretory granules, lots of RER; stains dark; ex is pancreas and parotid salivary gland

Question 36

merocrine — mucous

Answer 36

produce mucins (carbohydrates attached to protein core; heterochromatic nucleus (inactive cell), pale secretory granules, little RER; stain pale; important for protection and lubrication; ex are brunner's glands and goblet cells

Question 37

merocrine — mixed

Answer 37

seromucous glands; mucous cells are tubules, serous cells are serous demilunes (half-moon shaped); ex is submandibular salivary gland

Question 38

exocrine glands — secretory part

Answer 38

alveolar or acinar (serous), tubular (mucous), tubuloalveolar (mixed)

Question 39

myoepithelial

Answer 39

surround acinar and contract gland in effort to delivery product (weakly contractile)