Skin

Question 1

What is the skin?

Answer 1

Largest organ in the body- acts as a combination of the 4 primary tissues.

Question 2

What is the name of the skin system?

Answer 2

Integumentary system.

Question 3

What are the 3 layers of the skin?

Answer 3

Epidermis- outer (epithelial, covers surfaces)
Dermis- middle (connective; gives structure)
Hypodermis- inside layer

Question 4

What is the epidermis?

Answer 4

Outer layer of skin.

Question 5

What does the epidermis consist of?

Answer 5

5 strata.

Question 6

What type of epithelia is the epidermis?

Answer 6

Stratified squamous keratinising epithelium.

Question 7

What are the 4 types of epidermal cell?

Answer 7

Keratinocytes- keratin/sulfur for hard resilience
Melanocytes- pigment formation
Langerton cells- immune surveillance
Merkel cells- touch receptors

Question 8

What do keratinocytes do?

Answer 8

Contain keratin and sulfur to provide resilience.

Question 9

What are melanocytes responsible for?

Answer 9

Pigment formation.

Question 10

What are Langerton cells responsible for?

Answer 10

Immune surveillance.

Question 11

What are Merkel cells responsible for?

Answer 11

Touch receptors.

Question 12

What do the epidermal layers act as?

Answer 12

A continuum from basement membrane to skin surface.

Question 13

Are the epidermal layers sharply defined?

Answer 13

No.

Question 14

What is keratinisation?

Answer 14

Organic process by which keratin is deposited in cells.

Question 15

Why does epidermal thickness differ?

Answer 15

Some areas require thin or thicker skin (e.g. hands and feet).

Question 16

What are the 2 layers of the dermis?

Answer 16

Papillary layer (loose connective tissue- cellular)
Reticular layer (dense connective tissue- fibrous)

Question 17

What does the papillary layer consist of?

Answer 17

Loose connective tissue- cellular nature.

Cellular, protective against pathogens, blood vessels and nerve endings present.

Question 18

What does the reticular layer consist of?

Answer 18

Dense connective tissue- fibrous nature.

Collagen bundles, elasticity.

Question 19

What is waterproofing a function of?

Answer 19

Epidermis.

Question 20

What waterproofs the cells?

Answer 20

Keratinisation

Intercellular spaces also filled with lipid cement.

Question 21

How does keratin originate?

Answer 21

Originates as lamellate granules in the stratus granulosom.

Question 22

What is skin colour regulated by?

Answer 22

Melanin.

Question 23

What is the function of hair?

Answer 23

Thermoregulatory but not in humans.

Question 24

Where do hair follicles originate?

Answer 24

Epithelial layer.

Question 25

What are nails protected by?

Answer 25

Nail plate- keratin surface.

Nail bed underneath.

Question 26

How is the nail bed structured?

Answer 26

Specialised form of epithelium, has the same 4 layers of the epidermis as skin, nail plate analogous too s. corneum.

Question 27

What are the types of gland in the skin?

Answer 27

Sebaceous- hair follicles/sebum
Apocrine- protein-rich BO
Eccrine- sweat

Question 28

Where are eccrine (sweat) glands located?

Answer 28

Dermis, thermoregulatory water secretion.

Question 29

How does skin repair?

Answer 29

Coagulation pathways.