Epithelium and Surface Specialisations

Question 1

Define epithelial

Answer 1

Sheets of contiguous cells of varied embryonic origin that cover the external surfaces and line many internal surfaces

Question 2

What is the position, structure and function of the basal membrane?

Answer 2

• Located under the epithelia
• Made from a type of extracellular matrix
• connective tissue providing structure and support

Question 3

What are the 3 types of simple epithelium?

Answer 3

• Squamous
• Cuboidal
• Columnar

Question 4

Give one function and location of simple squamous epithelium

Answer 4

• Fluid barrier/Fast material exchange

- Bowman’s capsule/Lung serosa

Question 5

Give one function and location of simple cuboidal epithelium

Answer 5

• Absorption/Barrier

- Thyroid/Kidney tubules

Question 6

Give one function and location of simple columnar epithelium

Answer 6

• Secretion/Lubrication

- Stomach lining/Small intestine

Question 7

What does the term ‘stratified epithelium’ mean?

Answer 7

Multiple layered epithelium

Question 8

What is ‘pseudostratified epithelium’?

Answer 8

Columnar epithelium with nuclei at different levels giving the impression of multiple layers

Question 9

Give one function and location of pseudostratified columnar epithelium

Answer 9

• Secretion/Particle trapping

- Nasal cavity/Trachea lining

Question 10

What are the renewal rates of two types epithelium in the respiratory tract?

Answer 10

Trachea - 1-2 months
Alveoli - 8 days
Goblet Cells - 10 days
Clara Cells - Never

Question 11

What is transitional epithelium and what is its function and location?

Answer 11

• Epithelial cells of varying shape
• Protects underlying tissue
• Located in urinary tract ONLY

Question 12

What are the two types of stratified squamous epithelium and what is their function?

Answer 12

• Keratinised and Non-Keratinised

- Protect against abrasion

Question 13

Give 3 types of epithelial cell surface specialisations and their function

Answer 13

Keratin - Prevents water loss and prevents against abrasion
Cilia - Controls micro-movement of luminal contents
Goblet Cells - Mucus secretions moisten and lubricate
Clara Cells - Protect bronchioles and act as respiratory stem cells
Microfold Cells
Stereocilia

Question 14

What cells are dysfunctional and what is deficient in Cystic Fibrosis

Answer 14

• Goblet Cells

- Cl- ions

Question 15

What is the function and location of Microfold Cells?

Answer 15

• Portal of entry to trap pathogens to initiate an immune response
• Found in small intestine

Question 16

What is the function and location of Stereocilia?

Answer 16

• Respond to fluid motion to aid hearing and balance

- Found in inner ear

Question 17

What conditions result from damage to respiratory epithelium?

Answer 17

• Bronchitis
• Emphysema
• COPD
• Asthma

Question 18

What is the result of chronic respiratory epithelium damage?

Answer 18

• More goblet and basal cells
• Clara cells die
• Fibroblasts lay down scar tissue