Epithelial tissues

Question 1

Features of epithelial tissues

Answer 1

-Lines all body surfaces
-Barrier function
-Arranges as continuous sheets of tightly bound cells]
-Provide protection against microbial invasion
-Regulate movement of substances
-Epithelial cells are polarised
-Diffusion between blood and tissues
-Absorption of nutrients
-Secretion of sweat, mucus etc

Question 2

Surfaces
-apical
-basal
-lateral

Answer 2

Apical (external) - adjacent to/or facing the lumen/external surface

Basal (interior) - Adjacent to/or facing the interior surface

Lateral - Adhered to each other

Question 3

Classification

Answer 3

Simple - one layer
Stratified - multiple layers of the same cell
Pseudostratified - cilia present, nuclei at different locations

Squamous - thin oval like
Cuboidal - cube like
Columnar - longer and thin
cuboidal
Transitional - Composed of
multiple layers of
different cells
which allows
stretching

Question 4

Specialisations

Answer 4

Keratin - strong protective layer

Microvilli - increase apical surface area

Cilia - movement of particulate matter

Question 5

Simple squamous

Answer 5

Lines surfaces involved in passive diffusion
Found in lungs and capillaries

Question 6

Simple cuboidal

Answer 6

Lines small ducts and tubules involved in secretion/absorption
Found in renal tubules and small salivary gland ducts

Question 7

Simple columnar

Answer 7

Lines absorptive surfaces
Found in the small intestine (microvilli present can facilitate transport of ovum from ovary to uterus)

Question 8

Pseudostratified columnar ciliated

Answer 8

Ciliary action propel surface layer of mucus towards pharynx
Found in airways of respiratory system

Question 9

Stratified cuboidal

Answer 9

Secretory
Rare, found in some secretory ducts

Question 10

Stratified columnar

Answer 10

Secretory and protective
Rare, found in male urethra and lining of some glands

Question 11

Stratified squamous epithelia

Answer 11

Protection from mechanical abrasion
Found in epidermis and oral cavity
Can be keratinised or nonkeratinised.

Cells mature from basal layer from continuously dividing cells and migrate to surface eventually shedding as anucleate squames

Question 12

Transitional epithelium

Answer 12

Allows for expansion and stretch
Found only in the bladder

Question 13

Are epithelial tissues vascularised

Answer 13

no