PRELIM: EPITHELIAL TISSUE

Question 1

is a tissue in which cells are bound
tightly together structurally and functionally to form a sheetlike or tubular structure with little extracellular material between the cells.

Answer 1

EPITHELIUM

Question 2

facing the sheet’s free surface

Answer 2

APICAL SIDE

Question 3

facing a basement membrane and
underlying connective tissue

Answer 3

BASAL SIDE

Question 4

pinocytosis of material at the
apical side

Answer 4

TRANSCYTOSIS

Question 5

at the basolateral side

Answer 5

EXOCYTOSIS

Question 6

a thin extracellular layer of specialized proteins, usually having two parts: a basal lamina and a more fibrous reticular lamina

Answer 6

BASEMENT MEMBRANE

Question 7

2 parts of Basement membrane:

Answer 7

BASAL LAMINA
RETICULAR LAMINA

Question 8

is a thin meshwork of type IV collagen and laminin produced by the epithelial cells

Answer 8

BASAL LAMINA

Question 9

contains type III collagen and anchoring of VIII collagen, all secreted by cells of the immediately adjacent connective tissue

Answer 9

RETICULAR LAMINA

Question 10

FUNCTIONS OF BASEMEMENT MEMBRANE:

Answer 10

 attach epithelia to connective tissue
 regulate (filter) substances passing from connective tissue into epithelia
 provide a guide or scaffold during tissue regeneration after injury
 compartmentalize epithelial cells from other tissues

Question 11

INTERCELLULAR JUNCTIONS
3 MAJOR TYPES

Answer 11

TIGHT OR OCCLUDING JUNCTIONS
ADHERENT OR ANCHORING JUNCTIONS
GAP OR COMMUNICATING JUNCTIONS

Question 12

TIGHT OR OCCLUDING JUNCTIONS

Answer 12

Claudin and occludin surround the apical ends of the cells and prevent paracellular passage of substances (between the cells.)

Question 13

ADHERENT OR ANCHORING JUNCTIONS

Answer 13

• formed by interacting proteins of the cadherin family
• points of strong attachment holding together cells of the epithelium

Question 14

encircle epithelial cells just below their tight junctions or scattered

Answer 14

Zonula adherens

Question 15

desmos (binding) soma (body) disc shaped structures

Answer 15

Desmosomes

Question 16

composed of transmembrane integrins attach cells to proteins of the basal lamina

Answer 16

Hemidesmosomes

Question 17

• Mediate intercellular communication rather than adhesion or occlusion between cells
• Connexins form hexameric complexes called connexons

Answer 17

GAP OR COMMUNICATING JUNCTIONS

Question 18

APICAL STRUCTURES OF EPITHELIAL CELLS

• Brush or striated border
• increase epithelial cells’ apical surface area for absorption

Answer 18

MICROVILLI

Question 19

APICAL STRUCTURES OF EPITHELIAL CELLS

• Important components of inner ear
  sensory cells
• for absorption in tissues of male
  reproductive tract

Answer 19

STEREOCILIA

Question 20

• larger projecting structures with a
  well-organized core of microtubules
• primary cilium: not motile but enriched with receptors and signal transduction complexes for detection of light, odors, motion, and flow of liquid past the cells

Answer 20

CILIA

Question 21

assembly of microtubules; axon: axis, nema: thread

Answer 21

AXONEME

Question 22

TYPES OF EPITHELIA
2 main groups:

Answer 22

 Covering – lining epithelia
 Secretory – glandular epithelia

Question 23

Cells of covering epithelia are organized into one or more layers that cover the surface or line the cavities of an organ

Answer 23

COVERING OR LINING EPITHELIA

Question 24

one cell layer

Answer 24

SIMPLE EPITHELIA

Question 25

two or more layers

Answer 25

STRATIFIED EPITHELIA

Question 26

two or more layers

Answer 26

STRATIFIED EPITHELIA

Question 27

TYPE OF SIMPLE EPITHELIA thin cells

Answer 27

Squamous

Question 28

TYPE OF SIMPLE EPITHELIA cell width and thickness roughly similar

Answer 28

Cuboidal

Question 29

TYPE OF SIMPLE EPITHELIA cells taller than they are wide

Answer 29

Columnar

Question 30

MORPHOLOGICAL TYPES OF EPITHELIA elongated nuclei

Answer 30

COLUMNAR CELLS

Question 31

MORPHOLOGICAL TYPES OF EPITHELIA flattened nuclei

Answer 31

SQUAMOUS CELLS

Question 32

MORPHOLOGICAL TYPES OF EPITHELIA spherical nuclei

Answer 32

CUBOIDAL OR PYRAMIDAL

Question 33

Classified according to the cell shape of the superficial outer layer(s)

Answer 33

STRATIFIED EPITHELIA

Question 34

packed with keratin filaments

Answer 34

KERATINIZED

Question 35

with relatively sparse keratin

Answer 35

NONKERATINIZED

Question 36

found mainly in the epidermis skin, where it helps prevent dehydration from the tissue

Answer 36

STRATFIED SQUAMOUS KERATINIZED EPITHELIUM

Question 37

accumulate keratin

Answer 37

KERATINIZATION

Question 38

lines moist internal cavities (ex. Mouth, esophagus, and vagina) where water is not a problem

Answer 38

STRATIFIED SQUAMOUS NONKERATINIZED EPITHELIUM

Question 39

occurs in the excretory ducts of salivary and sweat glands

Answer 39

STRATIFIED CUBOIDAL EPITHELIUM

Question 40

is seen in the conjunctiva lining the eyelids, where it is both protective and mucus secreting

Answer 40

STRATIFIED COLUMNAR EPITHELIUM

Question 41

lines much of the urinary tract, extending from the kidneys to the proximal part of the urethra.

Answer 41

TRANSITIONAL EPITHELIUM or UROTHELIUM

Question 42

– superficial layer of large, dome-like cells - These cells protects underlying tissues from the hypertonic and potentially cytotoxic effects of urine

Answer 42

UMBRELLA CELLS

Question 43

tall, irregular cells all are attached to the basement membrane but their nuclei are at different levels and not all cells extend to the free surface, giving a stratified appearance Ex. Lining the upper respiratory tract where the cells are also heavily ciliated

Answer 43

PSEUDOSTRATIFIED COLUMNAR EPITHELIUM