Epithelia

Question 0

What is the basement membrane?

Answer 0

A thin, flexible, acellular layer which lies between epithelial cells and the subtending connective tissue.

Question 1

What are epithelia?

Answer 1

Sheets of contiguous cells, of varied embryonic origin, that cover the external surface of the body and line internal surfaces

Question 2

What is the structure of the basement layer?

Answer 2

Consists of a basal lamina which is laid down by epithelial cells and therefore lies closest to them.
Its thickness can be increased by a variable thick layer of type III collagen elaborated by the subtending connective tissue.

Question 3

What is the function of the basement membrane?

Answer 3

It is a strong, flexible layer to which epithelial cells adhere.
Serves as a cellular and molecular filter

Question 4

List some functions of simple squamous cells

Answer 4

Lubrication (pericardium, peritoneum)
Gas exchange (alveoli)
Barrier (Bowman’s capsule)
Active transport by pinocytosis (mesothelium and endothelium)

Question 5

List some functions of simple cuboidal cells

Answer 5

Absorption; conduit; secretion; barrier; hormone synthesis, storage and mobilisation

Question 6

What type of epithelia is found in the oesophagus?

Answer 6

Stratified squamous

Question 8

What type of epithelia is found in the trachea?

Answer 8

Pseudostratified ciliated columnar

Question 9

What type of epithelial cells are found in the alveoli?

Answer 9

Type 1 - Squamous - 90% - permit gas exchange

Type 2 - Cuboidal - 10% - they produce surfactant

Question 10

What type of epithelial cells are found in the urinary tract?

Answer 10

Transitional

Question 11

What type of epithelia is found in the urethra?

Answer 11

Stratified columnar

Question 12

What type of epithelial cells are found in the skin?

Answer 12

Keratinised stratified squamous