Epithelial Tissue

Question 1

Epithelial tissue
WHAT + FUNCTION

Answer 1

• Sheet of cells that covers a body surface or lines a body cavity.

Function
1. Protection
2. Absorption
3. Filtration
4. Excretion
5. Secretion
6. Sensory Reception

Question 2

2 types of Epithelial tissue

Answer 2

(1) Covering and lining epithelium
- Forms outer layer of the skin,
- Lines the open cavities of digestive, respiratory systems etc.
- Cover walls or organs of closed ventral cavities.

(2) Glandular epithelium
- Surrounds glands within the body.

Question 3

4 characteristics of epithelial tissue

Answer 3

(1) Polarity
(2) specialized contacts
(3) Supported by connective tissue
(4) Avascular and innervated

Question 4

Polarity

Answer 4

All epithelium has an apical surface (facing the lumen) and a lower attached basal surface (faces underlying tissue) that differ in structure and function.

Question 5

Specialised contacts

Answer 5

Epithelial cells fit close together and form a continuous sheet. They do this with tight junctions and desmosomes.

Question 6

Supported by connective tissue

Answer 6

The basement membrane reinforces the epithelium and helps to resist stretching and tearing.

Question 7

Avascular and innervated

Answer 7

• contains no blood vessels + supplied by nervous fibres.
• high ability to regenerate and can reproduce itself as long as it receives adequate nutrition.

Question 8

Simple epithelial

Answer 8

single layer of cells

Question 9

Stratified epithelium

Answer 9

two or more stacked cell layers

Question 10

squamous cells

Answer 10

flat and scale-like

Question 11

cuboidal cells

Answer 11

box like

Question 12

Columnar cells

Answer 12

tall, column-shaped

Question 13

Stratified Squamous Epithelium

Answer 13

Function
- Protects areas exposed to abrasion

Location
- Linings of oesophagus, mouth/ external part of skin

Question 13

Simple squamous epithelium

Answer 13

Function
- to absorb, secrete and filtrate

Location
- where diffusion/ fliteration occurs eg. alveoli

Question 13

Simple cuboidal epithelium

Answer 13

Function
- to absorb + secrete
- display cilia on there surface

Location
- in small ducts of glands + kidney tubules

Question 14

Simple columnar epithelium

Answer 14

Function
- to absorb + secrete
-microvilli on surface

Location
- digestive tract

Question 15

Pseudostratified columnar epithelium

Answer 15

Function
- secretion + absorbs

Location
- Lines respiratory tract

Question 16

Transitional epithelium

Answer 16

Function
- Readily stretches, stores urine

Location
- Lines bladder, ureters, urethras

Question 17

Gland

Answer 17

One or more cells that produce/secrete a specific product (which contains proteins + water based)

Question 18

Endocrine gland

Answer 18

Internally secreting

Question 19

Exocrine gland

Answer 19

Externally secreting

Question 20

Unicellular gland

Answer 20

One cell type

Question 21

Multicellular glands

Answer 21

More than one cell type