Epithelia

Question 1

What is a mucus membrane?

Answer 1

Lines internal tubes that open to the exterior (ie respiratory, alimentary and urinary tracts)

Question 2

What makes up a mucus membrane?

Answer 2

Epithelium 
Lamina propria (connective tissue)
Muscularis mucosae (smooth muscle)

Question 3

What part of a mucous membrane is only found in the alimentary tract?

Answer 3

Muscularis mucosae (smooth muscle)

Question 4

What can sometimes be found in the lamina propria of mucus membranes?

Answer 4

Peyer’s patches (aggregations of lymphocytes)

Question 5

What is a serous membrane?

Answer 5

A thin, 2 part membrane that lines closed body cavities

Question 6

What are the names given to the outer and inner parts of the serosa membranes?

Answer 6

Outer- parietal serosa

Inner- visceral serosa

Question 7

What is the special name given to the simple squamous epithelium of the peritoneum, pleural sac and pericardial sac?

Answer 7

Mesothelium

Question 8

Where does the basement membrane (basement lamina) lie?

Answer 8

In between epithelial cells and subtending connective tissue

Question 9

What is a basement membrane?

Answer 9

An acellular, thin, flexible, strong, filter of molecules
Connecting epithelia to subtending ct
It is made of type 3 collagen

Question 10

Where are simple squamous epithelium found?

Answer 10

Lining blood and lymph vessels (endothelial)
Lining body cavities (mesothelium)
Gas exchange epithelium- pulmonary alveoli
Bowman’s capsule
Loop of henle

Question 11

What are the functions of simple squamous epithelium?

Answer 11

Lubrication
Gas exchange
Barrier
Active transport by pinocytosis

Question 12

Where are simple cuboidal epithelium found?

Answer 12

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

Question 13

What is the function of the simple cuboidal epithelium?

Answer 13

Absorption
Secretion
Barrier (ovary)
Hormone synthesis, storage and mobilisation (thyroid)

Question 14

Where do you find simple columnar epithelium?

Answer 14

Stomach lining and gastric glands

Small intestine and colon

Question 15

What are the functions of simple columnar epithelium?

Answer 15

Absorption (small intestine and colon, gallbladder)
Secretion (stomach lining, small intestine and colon)
Lubrication (small intestine and colon)
Transport (oviduct)

Question 16

Where do you find pseudostratified epithelium?

Answer 16

Lining of nasal cavity, trachea and bronchi

Question 17

What is the function of pseudostratified epithelium?

Answer 17

Secretion (respiratory tract)
Mucus secretion
Particle trapping and removal

Question 18

Where are stratified squamous (non-keratinised) epithelium found?

Answer 18

Oral cavity
Oesophagus
Larynx
Vagina
Part of the anal canal

Question 19

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

Answer 19

Protection against abrasion

Reduces water loss but remains moist

Question 20

Where do you find stratifies squamous (keratinised) epithelium?

Answer 20

Surface of skin

Question 21

What are the functions of stratified squamous ‘keratinised’ epithelium?

Answer 21

Protection against abrasion and physical trauma
Prevents water los
Prevents ingress of microbes
Shields against UV light damage

Question 22

Where do you find transitional epithelium?

Answer 22

Ureter
Bladder
Urethra

Question 23

What are the functions of transitional epithelium?

Answer 23

Distensibility

Protection of underlying tissue from toxic chemicals

Question 24

What are the modern names for the layers of the epidermis?

Answer 24

Horny layer
Granular layer
Prickle cell layer
Basal layer

(Remember the mnemonic: Horny Grannies Poke Bums)

Question 25

What are the latin names for the layers of the epidermis?

Answer 25

Stratum corneum Stratum granulosum Stratum spinosum Stratum basale

Question 26

Which layers of the epidermis consist of dead cells?

Answer 26

The horny layer/stratum corneum

Question 27

Which layers of the epidermis consist of living cells?

Answer 27

The granular layer/stratum granulosum The prickle cell layer/stratum spinosum The basal layer/stratum basale

Question 28

What is the dermis made of?

Answer 28

Connective tissue

Question 29

How long does it take for a cell to move through the layers of the epidermis?

Answer 29

28-40 days

Question 30

What are the 3 cell types found in the epidermis?

Answer 30

Melanocytes, keratinocytes and langerhan cells

Question 31

What are keratinocytes and where are they produced?

Answer 31

They produced keratin which strengthens cells, they are produced in the basal layer but migrate up into the prickle cell layer

Question 32

What do keratinocytes differentiate into in the granular layer?

Answer 32

Corneocytes (dead cells that have no organelles)

Question 33

What are langerhans cells and where are they found?

Answer 33

Dendritic cells,that present antigens to T lymphocytes (and mediate immune responses), they are found in the prickle cell layer/stratum spinosum

Question 34

What are melanocytes and where are they found?

Answer 34

Dendritic cells that produce melanin, they are found in the basal layer

Question 35

What is the function of melanocytes and melanin?

Answer 35

Melanocytes produce melanin in melanosomes which is transferred to keratinocytes. The melanin then covers the superior nuclear region of the cells and protect the DNA from UV damage

Question 36

How is the pancreas both an exocrine and endocrine gland?

Answer 36

Exocrine- pancreatic acini | Endocrine- islet of langerhans

Question 37

How are glands defined in terms of structure?

Answer 37

Uni/multicellular Acinar (like grapes)/tubular (goblet shape) Coiled/branched

Question 38

What are the 3 methods of secretion by glands?

Answer 38

Merocrine (exocytosis) Apocrine (secret droplets covered in plasmalemma) eg fat droplets of milk Holocene (whole cell breaks down) eg sebaceous glands of skin

Question 39

How do you name epithelial tissues?

Answer 39

1) by the number of cells (simple/stratified) | 2) by the shape of cells (columnar/cuboidal/squamous)

Question 40

What are pseudostratified columnar epithelia?

Answer 40

When all cells are attached to the basement membrane (simple) but there is the illusion of stratified cells eg in trachea and nasal cavity (Not all cells reach the lumen BUT all cells are attached to basement membrane)

Question 41

What it transitional epithelia?

Answer 41

Cells that are Stratified columnar when relaxed but become stratified cuboidal when stretched eg bladder

Question 42

What are the 3 layers of the skin?

Answer 42

Epidermis Dermis Hypodermis (subcutaneous layer)

Question 43

What are the functions of the skin? (7)

Answer 43

``` Protection Sensation Thermal regulation Excretion and secretion Immunity Endocrine Growth ``` (Remember the mnemonic: People Sometimes Think Eggs Smell Incredible Eggy and Gross)