L4- Epithelial tissue

Question 1

Define epithelial

Answer 1

A sheet of contiguous cells, of varied embryonic origin, that covers the external surface of the body and line many internal surfaces

Question 2

Broad function of epithelia

Answer 2

Protection, secretion, absorption, sensation

Question 3

Define basement membrane

Answer 3

Thin tissue that separates the lining of internal and external body surfaces from underlying tissue
Eg. Basal lamina ad reticular lamina

Question 4

Epithelia classified on the basis of

Answer 4

Shape and arrangement

Question 5

Types of epithelia arrangement

Answer 5

Simple

Stratified- named based on the superficial layer

Question 6

Simple

Answer 6

Single layer

Question 7

Stratified

Answer 7

More than one layer

Question 8

Pseudostratified

Answer 8

All cells in contact with basement membrane, not all cel reach epithelia and nucleus at different levels

Question 9

Name the type of simple epithelia

Answer 9

• simple squamous
• simple cuboidal
• simple columnar

Question 10

Name the types of stratified

Answer 10

• stratified squamous non keratinised
• stratified squamous keratinised
• stratified cuboidal
• stratified columnar

Question 11

Function of simple squamous with examples

Answer 11

• gas exchange e.g. alveoli
• barrier to fluids- Bowman capsule
• Secrete lubrications fluids- serous membrane

Question 12

Function of simple cuboidal epithelium

Answer 12

• hormone synthesis- thyroid gland
• absorption and secretion- kidney
• absorption and conduit- pancreatic duc

Question 13

Function of simple columnar epithelium

Answer 13

• absorption- gall bladder
• secretion- stomach lining, small intestine, colon
• lubrication- small intestine, colon

Question 14

Function of pseudostratified columnar epithelium

Answer 14

Mucus secretion and particle trapping - upper respiratory tract

Question 15

Function of stratified squamous non keratinised

Answer 15

• Protect again abrasion - vagina, oesophagi s, anal canal

- reduce water loss (same as above)

Question 16

Feature of stratified squamous keratinised

Answer 16

Outermost layer- squamous cells have lost their nuclei and cornfield (keranocytes)- form strum corneum

Question 17

Function of stratified squamous keratinised epithelium

Answer 17

• found at the epidermis of the skin
• reduce water loss and ingress
• prevent toxin and microbial ingress
• protect against abrasion
• protect against UV light damage

Question 18

Features of the transitional epithelium

Answer 18

Can be relaxed stretched

Question 19

Function of transitional epithelium

Answer 19

Urinary tracts:

• distensibility
• protection from toxic chemicals

Question 20

Feature of stratified cuboidal and columnar epithelium

Answer 20

Nt common

Question 21

Function of stratified cuboidal epithelium

Answer 21

secretion and conduit in sweat glands

Question 22

Function of stratified columnar epithelium

Answer 22

Secretion and lubrications in male urethra

Question 23

Name 3 surface specialisations of the epithelia

Answer 23

• micro villi
• sterocilia
• cilia

Question 24

Microvilli

Answer 24

Found in the intestine- increase surface area for absorption

Question 25

Stereocilia

Answer 25

- ductus deference’s, epididymis, inner ear | - respond to fluid motion

Question 26

Cilia

Answer 26

Trachea | - muco-ciliary escalator