Epithelium

Question 1

Types of tissues

Answer 1

Epithelial
Muscular
Connective
Nervous tissue

Question 2

2 types of epithelial tissues

Answer 2

Lining epithelial cells
Glandular epithelia (make up most of the glands in the body)

Question 3

Examples of epithelial tissues

Answer 3

o The outer layer of the skin .
o The inner surface of the digestive and respiratory cavities.
o The inner surface of the heart and blood vessels.
o The walls and the organs of the closed ventral body cavities.
o The ducts of the exocrine glands.

Question 4

In epithelial cells the cell to cell contact is at …. but the extracellular material is at……

Answer 4

Maximum

Minimum

Question 5

Each epithelial cell is supported by

Answer 5

A basment membrane called basal lamella

Question 6

Epithelial cells according to blood vessels

Answer 6

Avascular (have no blood cells)

Question 7

Epithelial cells are derived from

Answer 7

Embryonic germ layers including endoderm, mesoderm and ectoderm

Question 8

Apical surface

Answer 8

free surface exposed at the body surface or at the lumen (space) of the body cavity, duct, tube or vessel

Question 9

Basal surface of epithelium rests on

Answer 9

Basement membrane

Question 10

Basement membrane (basal lamella)

Answer 10

non- living adhesive material secreted by the epithelium and the underlying connective tissue .

Question 11

Why is the epithelial tissues attached to basement membrane attached to connective tissues

Answer 11

Because it’s avascular and needs blood supply from connective tissues

Question 12

Epithelial cells are often characterized by frequent cell division why?

Answer 12

because they are exposed to wear and tear and injury, necessitating replacement.

Question 13

What epithelial cell doesn’t have a basement membrane, apical surface nor wear and tear

Answer 13

Endocrine glands

Question 14

Polarity is in most of epithelial cells. What is it

Answer 14

structural and functional asymmetry

Question 15

In simple epithelia name the 3 surfaces

Answer 15

Apical (free)
Lateral (between each cell and the other)
Basal (attached to the basal lamina)

Question 16

Apical / surface modification

Answer 16

Microvilli
Stereocilia
Cilia and flagella

Question 17

Microvilli

Answer 17

irregular, fingerlike projections with an extracellular glycoprotein layer (cell at) . Can be seen under LM

Question 18

Microvilli contain a core of … and is attached to

Answer 18

Actin filaments

Terminal web

Question 19

Stereocilia and where it’s usually found

Answer 19

Long motile microvilli found in places with absorptive or sensory function

Question 20

Stereocilia eg

Answer 20

In epididymis, ductus deferens, (hair cells of maculae and corti ) in internal eat

Question 21

Cilia

Answer 21

elongated, highly motile structures on the surface of some epithelial cells

Question 22

Cilia is much longer and ….times wider than a microvillus

Answer 22

2

Question 23

A ciliated cell of the tracheaقصبة هوائية٠ lining is estimated to have about .. cilia

Answer 23

250

Question 24

Flagella is only found in

Answer 24

Spermatozoa

Question 25

Flagella and cilia are different in

Answer 25

Flagella are much longer and are normally limited to one flagellum per cell

Question 26

Cilia and flagella are made of

Answer 26

Axoneme

Question 27

Axoneme

Answer 27

9 doubles and 1 double of microtubules in the middle similar to centrioles

Question 28

At the base of cilia or flagell there is a

Answer 28

Basal body similar to centrioles in structure (9packs of 3)

Question 29

Brush / striated border mocrovilli

Answer 29

microvilli-covered surface of simple epithelium

Question 30

Cores of brush borders are made of ....

Answer 30

Parallel actin micro filaments

Question 31

Terminal web

Answer 31

a filamentous structure found at the apical surface of epithelial cells that possess microvilli.

Question 32

The micro filaments can contract and shorten by

Answer 32

Interacting with cytoplasmic myosin

Question 33

Microvilli usually cover

Answer 33

Apical surfaces of absorptive cells to increase their apical surface area when extended

Question 34

Where brush border is example

Answer 34

absorptive simple columnar epithelium lining the small intestines and the absorptive simple cuboidal epithelium lining the proximal tubules of the kidney.

Question 35

Cell junctions are usually in

Answer 35

Lateral membranes

Question 36

If the junction extends around the entire cell perimeter it is called

Answer 36

Zonula

Question 37

If the junction presents as strip shaped or band-shaped it is called

Answer 37

Fascia

Question 38

If the junction presents as small circular or spot like it is called

Answer 38

Macula

Question 39

Brush / striated border mocrovilli

Answer 39

microvilli-covered surface of simple epithelium

Question 40

Cores of brush borders are made of ....

Answer 40

Parallel actin micro filaments

Question 41

Terminal web

Answer 41

a filamentous structure found at the apical surface of epithelial cells that possess microvilli.

Question 42

The micro filaments can contract and shorten by

Answer 42

Interacting with cytoplasmic myosin

Question 43

Microvilli usually cover

Answer 43

Apical surfaces of absorptive cells to increase their apical surface area when extended

Question 44

Where brush border is example

Answer 44

absorptive simple columnar epithelium lining the small intestines and the absorptive simple cuboidal epithelium lining the proximal tubules of the kidney.

Question 45

Cell junctions are usually in

Answer 45

Lateral membranes

Question 46

If the junction extends around the entire cell perimeter it is called

Answer 46

Zonula

Question 47

If the junction presents as strip shaped or band-shaped it is called

Answer 47

Fascia

Question 48

If the junction presents as small circular or spot like it is called

Answer 48

Macula