L4: Epithelial Cell Functions

Question 1

Where are epithelial cells located?

Answer 1

Covering body surfaces & lining body cavities

Question 2

Functions of epithelial cells

Answer 2

1) Protection
2) Selective Barrier
3) Gland Formation
4) Reabsorption

Question 3

Is epithelial or endothelial cells just a simple epithelium ?

Answer 3

Endothelial

Question 4

What does endothelial cells line in our body?

Answer 4

Inner surfaces of blood vessels & lymph vessels

Question 5

3 plasma membrane regions in epithelial cells?

Answer 5

1) Apical
2) Lateral
3) Basal

Question 6

3 examples of apical surfaces

Answer 6

1) Glycocalyx
2) Cilia
3) Microvilli

Question 7

Structure of glycocalyx

Answer 7

Dense, bush-like structure

Question 8

What happens to glycocalyx in the epithelial cells?

Answer 8

Protects the cells against mechanical & chemical damage

Question 9

Function of cilia

Answer 9

Capable of moving particles & fluid along epithelial surfaces

Question 10

Advantage of tightly packed microvilli

Answer 10

Absorption

Question 11

Function of lateral domain in epithelial cells?

Answer 11

Forms cell-cell junction like adherens junction & tight juntions

Question 12

What does the basal domain produce?

Answer 12

Produces a layer of specialised extracellular matrix called the basement membrane

Question 13

Function of the basal domain

Answer 13

Acts as a sieve (permeability barrier), controlling entry & exit from the cells

Question 14

What does the CFTR gene provide instructions for?

Answer 14

Provides instructions for making the protein CF transmembrane conductance regulator (CFTR)

Question 15

Function of the CFTR protein

Answer 15

A channel across membrane of cells that produce mucus, sweat, saliva, tears

Question 16

What does the mutated CFTR gene change in cystic fibrosis?

Answer 16

Changes a protein that regulates the movement of salt in & out of cells

Question 17

What are cadherins?

Answer 17

Transmembrane proteins that mediate cell-cell adhesions in animals

Question 18

Function of cadherin

Answer 18

Cease growth when cells come in contact with each other

Question 19

Describe contact inhibition

Answer 19

Regulatory mechanism that keeps cell growth only one cell thick

Question 20

Role of barrier function in the skin

Answer 20

Maintaining a physical barrier, communication between internal & external environments

Question 21

Role of gas exchange in lungs

Answer 21

Allows the body to supply oxygen & eliminate CO2

Question 22

Role of absorption in the gastrointestinal system

Answer 22

After digestion, materials being absorbed can be used by cells throughout the body

Question 23

Role of tight junctions in the GI system for absorption

Answer 23

Prevent passing of material between cells

Question 24

Reabsorption in kidneys

Answer 24

Movement of H2O & solutes from into or out of blood

Question 25

Role of secretion in pancreas-endocrine function

Answer 25

Create & release important hormones directly into the bloodstream