Basic Histology- Epithelial Cells

Question 1

Epithelium

Answer 1

covers body surfaces, lines body cavities, and forms glands

Question 2

Features of epithelial cells (5)

Answer 2

closely packed, avascular, connected to basal lamina, continuously renewed, polarized

Question 3

Basement membrane

Answer 3

thin extracellular sheets that is semipermeable that connect epithelium to connective tissue

Question 4

Basal lamina

Answer 4

made of type 4 collagen and laminin, produced by epithelium

Question 5

Reticular lamina

Answer 5

made of type 3 and 4 collagen, secreted by connective tissue

Question 6

Polarity of Epithelium

Answer 6

have distinct apical and basal layers

Question 7

How epithelium are renewed

Answer 7

continuous mitosis in basal layer

Question 8

How epithelium obtain nutrients

Answer 8

O2 and nutrients come from capillary diffusion in connective tissue

Question 9

4 ways to classify epithelial cells

Answer 9

of layers, shape of cells, shape of cell surface, keratinized vs. non-keratinized

Question 10

Number of cell layers

Answer 10

single (simple) or multiple (stratified)

Question 11

Shape of cells

Answer 11

squamous, cuboidal, columnar

Question 12

Shape of surface cells

Answer 12

stratified or pseudostratified

Question 13

Pseudostratified

Answer 13

cells that appear stratified but they all touch basal membrane and are actually simple

Question 14

Keratinized cells

Answer 14

found mostly in skin, barrier against abrasion, infection and water loss, cells are dead and lack nuclei and superficial levels

Question 15

Non-keratinized cells (4)

Answer 15

thinner with less keratin, alive and nucleated, less resistant to water loss but kept wet with glands, lines wet cavities

Question 16

Transitional epithelium

Answer 16

urothelium, epithelial lining of urinary tract, stratified

Question 17

Types of simple squamous epithelium

Answer 17

endothelium, endocardium, mesothelium

Question 18

Endothelium

Answer 18

lines blood and lymphatic system

Question 19

Endocardium

Answer 19

lines the heart

Question 20

Mesothelium

Answer 20

lines the walls of cavities in the body (abdominal, cardiac, and lung)

Question 21

Organization of the epithelium

Answer 21

desmosomes, gap junctions, association with basal lamina, cytoskeletal components

Question 22

Desmosomes

Answer 22

cadherin proteins, bind keratin

Question 23

Gap junction

Answer 23

permit rapid spread of signaling molecules between cells, also called nexus

Question 24

Association with basal lamina

Answer 24

hemidesmosomes, focal adhesions, chemical compounds, basal-apical specialization

Question 25

Hemidesmosomes

Answer 25

integrin proteins, binds intermediate filaments, anchors cell to basal lamina

Question 26

Focal adhesions

Answer 26

integrin proteins, binds actin filaments

Question 27

Chemical compounds of basal lamina

Answer 27

• laminin, type 4 collagen, glycosaminoglycans (GAGs)

Question 28

GAGs

Answer 28

glycosaminoglycans

Question 29

Cytoskeletal component

Answer 29

keratin

Question 30

Apical specialization

Answer 30

motile cilia and flagella, microvilli, stereocilia

Question 31

Microvilli

Answer 31

absorption, increase sialic acid

Question 32

Stereocilia

Answer 32

absorptive function in male testicular tubes, and sensory function in internal ear (hair cells)

Question 33

Zonulae

Answer 33

bandlike, encircle cell

Question 34

Lateral specializations

Answer 34

zonulae, maculae, and gap junctions

Question 35

Zonula occludens

Answer 35

tight junctions, seal off intercellualr space, attach to specific membrane occludins

Question 36

Zonula adherens

Answer 36

maintain seal made by tight junction

Question 37

Maculae

Answer 37

dislike, attach 2 cells at 1 spot

Question 38

Macular adherens

Answer 38

desmosome, adhere adjacent cells

Question 39

Basal specialization

Answer 39

hemidesmosomes