Epithelial Cells

Question 1

What does a mucous membrane consist of?

Answer 1

An epithelium (type depends on the site) lining the lumen of a tribe
An adjacent layer of connective tissue (often referred to as the lamina propria)
In the alimentary tract a third layer consisting of smooth muscle cells referred to as the muscularis mucosae

Question 2

What is a serous membrane?

Answer 2

A thin, two part membrane which lines certain closed body cavities. They envelop the viscera.
They line the peritoneum (which envelops many abdominal organs), the pleural sacs (which envelop the lungs) and the pericardial sac (which envelops the heart)

Question 3

What are epithelia?

Answer 3

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

Question 4

Do all epithelia sit on a basement membrane?

Answer 4

Yes

Question 5

Describe the basement membrane:

Answer 5

thin, flexible, acellular layer

It lies between epithelial cells and the subtending connective tissue

Question 6

What does the basement membrane consist of?

Answer 6

Basal lamina- laid down by epithelial cells (and therefore lies close to them)
Reticular fibrils (type III collagen), elaborated by the subtending connective tissue.

Question 7

When simple stratified epithelium lines the pleural sac, pericardial sac and peritoneum what is it called?

Answer 7

Mesothelium

Question 8

What is endothelium?

Answer 8

Simple squamous epithelium lining all vascular elements (arterial, venous, capillary and lymphatic)

Question 9

Locations of simple squamous epithelia

Answer 9

Lining of blood and lymph vessels (endothelium)
Lining of body cavities - pericardium, pleural sac, peritoneum (mesothelium)
Gas exchange epithelium (pulmonary alveoli)
Bowman’s capsule (kidney)
Loop of Henle (kidney)

Question 10

What are the functions of epithelia?

Answer 10

Lubrication (pericardium, pleura, peritoneum/viscera)
Gas exchange (pulmonary alveoli)
Barrier (Bowman’s capsule)
Active transport by pianocytosis (mesothelium and endothelium)

Question 11

Where can you find simple cuboidal epithelium?

Answer 11

Thyroid follicles
Small ducts of many exocrine glands
Kidney tubules
Surface of ovary (germinal epithelium)

Question 12

What are the functions simple cuboidal epithelium?

Answer 12

Absorption and conduit (exocrine glands)
Absorption and secretion (kidney tubules)
Barrier/covering (ovary)
Hormone synthesis, storage and mobilisation (thyroid)

Question 13

Where would you find simple columnar epithelium?

Answer 13

GI tract
Stomach lining and gastric glands
Small intestine and colon 
gallbladder
Large ducts of some exocrine glands
Oviducts
Uterus
Ductility efferentes of testis

Question 14

Functions of simple columnar epithelium

Answer 14

Absorption - small intestine and colon
Secretion - stomach lining and gastric glands, small intestine and colon
Lubrication - small intestine and colon
Transport - oviduct

Question 15

Do all pseudostratified cells have contact with the basement membrane?

Answer 15

Yes

Question 16

Where would you find pseudostratified epithelium?

Answer 16

Lining of nasal cavity, trachea and bronchi
Epididymis and ductus deferens
Auditory tube and part of tympanic cavity
Lacrimal sac
Large excretory ducts

Question 17

Functions of pseudostratified epithelia?

Answer 17

Secretion and conduit (respiratory tract, ductus deferens)
ABsorption (epididymis)
Mucus secretion (respiratory tract)
particle trapping and removal (respiratory tract)

Question 18

When you’re naming stratified squamous cells, which cells do you look at to describe the shape?
A. Cells closest to the basement membrane
B. Cells furthest from the basement membrane

Answer 18

B. Cells furthest from the basement membrane.

Question 19

Where would you find stratified squamous non-keratinised epithelium?
(Think about places where there may be abrasion)

Answer 19

Oral cavity
Oesophagus
Larynx
Vagina
Part of anal canal
Surface of cornea
Inner surface of eyelid

Question 20

What are the functions of stratified squamous non-keratinised epithelium?

Answer 20

Protection against abrasion (all sites)

Reduces water loss but remains most (all sites)

Question 21

What is the difference between keratinised and non-keratinised squamous epithelium?

Answer 21

Keratinised epithelium lose their nucleus e.g. Top layer of skin.

Question 22

The epidermis has a rich blood supply. True or false?

Answer 22

False. The epidermis don’t have a blood supply. They get their nutrient by diffusion.

Question 23

The dermis is well vascularised. True or false?

Answer 23

True.

Question 24

Which cells wander round the dermis?

Answer 24

Langerhans cells.
Professional antigen presenting cell - present an antigen to present to T cells.

Good because we are often cut.

Question 25

Melanocytes and Langerhans cells are dendritic. True or false?

Answer 25

True. They are both dendritic cells.

Question 26

Are there more melanocytes in people with darker skin colour?

Answer 26

No. There melanocytes produce more melanin however there is no increase in number of actual melanocytes.

Question 27

Locations of squamous keratinised epithelium?

Answer 27

Surface of skin

Limited distribution in oral cavity

Question 28

Where is transitional epithelium found?

Answer 28

In the urinary tract:
Renal calyces
Ureters
Bladder 
Urethra

Question 29

Functions of transitional (urinary) epithelium?

Answer 29

Distensibility

Protection of underlying tissue from toxic chemicals

Question 30

What is a gland?

Answer 30

A gland is an epithelial cell or collection of cells specialised for secretion.