Epithelia

Question 1

What are epithelial cells?

Answer 1

Cells that cover or line all the body surfaces

Question 2

What do all epithelial cells sit on?

Answer 2

Basement membrane

Question 3

What are tumours called that develop from epithelial cells?

Answer 3

Carcinomas

Question 4

What are epithelial cells connected by?

Answer 4

Tight junctions

Question 5

What are the three different shape of epithelial cells?

Answer 5

Columnar

Cuboidal

Squamous

Question 6

What are epithelial cells called if they only have one layer?

Answer 6

Simple

Question 7

What are epithelial cells called if they have more than one layer?

Answer 7

Stratified

Question 8

What are the cells called that are in contact with the lumen and BM?

Answer 8

Apical

Basal

Question 9

What is the effect of a thicker epithelium?

Answer 9

The greater the protection from abrasion, infection or caustic content

Question 10

What epithelium is found in blood vessels?

Answer 10

Simple squamous

Question 11

What epithelium is found in kidney tubules?

Answer 11

Simple cuboidal

Question 12

What epithelium is found in the GI tract?

Answer 12

Simple columnar

Question 13

What epithelium is found in the skin?

Answer 13

Stratified squamous

Question 14

What epithelium is found in the reproductive system?

Answer 14

Stratified cuboidal

Question 15

What epithelium is found in the respiratory system?

Answer 15

Pseudostratified columnar

Question 16

What epithelium is found in the bladder?

Answer 16

Transitional

Question 17

What does a single layer of flattened epithelium allow?

Answer 17

Exchange of gases, nutrients

Question 18

What does a single layer of cuboidal or columnar epithelium allow?

Answer 18

Transport system and ciliated surfaces

Question 19

What does multiple layers of a flattened epithelium allow?

Answer 19

A protective barrier

Question 20

What does one or many layers of columnar epithelium allow?

Answer 20

Secretory function

Question 21

Describe simple squamous epithelium

Answer 21

Single layer flattened cells

Individual cells are very thin with a central nucleus

Irregular shape

Close proximity to each other

Question 22

Where is simple squamous epithelium found?

Answer 22

Lining of body cavities

Question 23

Where is simple columnar epithelium found?

Answer 23

Lining of small intestines

Question 24

What three levels of folding are there in the small intestines?

Answer 24

Large folds to the naked eye

Microscopic villi covered by a SCE

Microvilli modifications of the apical surface of the epithelial cells

Question 25

What does simple columnar epithelium in the small intestine allow?

Answer 25

Increase in surface area for absorption Mucus secretion to lubricate gut contents

Question 26

What are the three surface modifications of simple columnar epithelium?

Answer 26

Mucus adheres to the brush border created by several hundred microvilli Goblet cells release mucus to lubricate gut contents BM stops epithelium joining to other tissues

Question 27

Where is pseudostratified ciliated columnar epithelium found?

Answer 27

In the respiratory tract

Question 28

Describe the structure of pseudostratified epithelium

Answer 28

All the cells adhere to the BM but because of the length and shape of the individual cells, it makes it seem like it has multiple layers

Question 29

Where is stratified squamous epithelium found?

Answer 29

Oesophagus, vagina, anal canal

Question 30

What is desquamation?

Answer 30

Flattened cells that are worn off and are shed from the surface

Question 31

What effect does stratified squamous keratinised epithelium have?

Answer 31

Resists water loss

Question 32

Where is stratified squamous keratinised epithelium found?

Answer 32

Skin

Question 33

Where is transitional epithelium found?

Answer 33

The bladder

Question 34

What feature allows transitional epithelium to stop leakage?

Answer 34

High numbers of tight junctions

Question 35

What are the different points of adherence?

Answer 35

Tight junctions Desmosomes Hemidesmosomes Gap junctions

Question 36

What are the different membrane proteins associated with the tight junctions?

Answer 36

Claudin and occludin

Question 37

What type of junctions are cell-cell?

Answer 37

Gap Tight Adhering Desmosome

Question 38

What type of junctions are cell-matrix?

Answer 38

Hemi-desmosome Focal adhesion

Question 39

What protein are associated with hemi-desmosome?

Answer 39

Membrane- integrin Cytoskeleton- Keratin Extracellular matrix- laminin

Question 40

What are the different ways molecule can pass through the epithelium layer?

Answer 40

Trans cellular movement Paracellular movement

Question 41

Two examples of trans cellular movement?

Answer 41

Absorption Secretion

Question 42

Example of paracellular movement

Answer 42

Diffusion

Question 43

What are sealing strands?

Answer 43

Multiple layers of claudin and occludin creating a better barrier

Question 44

What increases with an increase of number of sealing strands?

Answer 44

Resistance

Question 45

What are the different functions of tight junctions?

Answer 45

Barriers Fences- maintain the asymmetric distribution if lipids and proteins in the apical and basal membranes Gates- selective movement