Epithelia

Question 1

Define epithelium

Answer 1

Thin, continuous protective layer of cells that covers both the inside and outside of the body including blood vessels

Question 2

What are the functions of epithelia?

Answer 2

Protection, secretion, absorption, excretion, filtration, diffusion and sensory reception

Question 3

Which embryological germ layer are epithelial tissues derived from?

Answer 3

All 3- endoderm, ectoderm and mesoderm

Question 4

Which epithelial tissues are formed from the ectoderm?

Answer 4

The skin

Question 5

Which epithelial tissues are formed from the endoderm?

Answer 5

Gastrointestinal tract, respiratory tract, genitourinary tract, external acoustic meatus

(Interior spaces opening to exterior)

Question 6

Which epithelial tissues are formed from the mesoderm?

Answer 6

Pericardial sac, pleural sacs, peritoneum, blood vessels, lymphatic vessels

(Interior spaces which do not open to exterior)

Question 7

What is the function of simple squamous epithelia?

Answer 7

Diffusion and filtration (due to thinness)

Question 8

What is the function of simple cuboidal epithelium?

Answer 8

Absorption, secretion and protection

Question 9

Give an example of simple squamous epithelium

Answer 9

Bowman’s capsule

Question 10

Give an example of simple cuboidal epithelia

Answer 10

Lining of the collecting ducts of the kidney

Question 11

What is the function of simple columnar epithelium?

Answer 11

Absorption of nutrients, movement of lumen contents.

Question 12

Give an example of simple columnar epithelium

Answer 12

Lining of the crypts of Lieberkuhn

Question 13

What is the function of stratified squamous epithelia?

Answer 13

Protection from abrasion

Question 14

Give an example of stratified squamous epithelium

Answer 14

Lining of the wall of the oesophagus

Question 15

What is the function of transitional epithelium?

Answer 15

Protection and distendibility

Question 16

Give an example of transitional epithelium

Answer 16

Lining of the urinary tract (renal calyces, ureters, bladder, proximal urethra)

Question 17

What is the function of microvilli?

Answer 17

Absorption

Question 18

What is the function of stratified squamous keratinised epithelium?

Answer 18

Protection against abrasion, prevention of water loss

Question 19

What is the name for the layer of outermost dead cells of stratified squamous keratinised epithelium?

Answer 19

The stratum corneum

Question 20

Give an example of pseudostratified epithelium

Answer 20

Lining of conducting airways eg. Trachea

Question 21

What is the function of pseudostratified epithelia?

Answer 21

Secretion and absorption

Question 22

What is the function of cilia?

Answer 22

Motile, beat in order to move substances through the lumen

Question 23

What is the function of goblet cells?

Answer 23

Secretion of mucins (forms mucus when in contact with water)

Question 24

What is a serous membrane?

Answer 24

A membrane which surrounds the invaginated organ eg. Heart, lung, gut. Has inner and outer membrane.

Hand in balloon analogy

Question 25

What is the difference between serous and mucosal membranes?

Answer 25

Mucosal membranes line internal structures which open to the exterior eg. GI, respiratory, urinary tract

Serous membranes line closed body cavities eg. Peritoneum, pleural sacs, pericardial sac

Question 26

What is the function of club cells?

Answer 26

Protect the bronchiolar epithelium via the secretion of proteins including uteroglobin

Detoxification of harmful substances inhaled into the lungs with cytochrome P450 enzymes on SER

Act as a stem cell, differentiating into ciliated cells to regenerate the bronchiolar epithelium