Skin

Question 1

What system does skin belong to?

Answer 1

Integumentary.

Question 2

What are the 3 layers of the skin?

Answer 2

• Epidermins (outside layer).
• Dermis (middle layer).
• Hypodermis (inside layer).

Question 3

What is the structure of skin?

Answer 3

1) . Hair shaft.
2) . Pore of sweat gland duct.
3) . Endocrine sweat gland (in dermis).
4) . Pacinian corpuscle (in dermis).
5) . Hair follicle receptor (in dermis).

• Epidermis.
• Dermis.
• Hypodermis.

Question 4

What are the 4 main types of cells that make up the epidermis?

Answer 4

• Keratinocytes.
• Melanocytes.
• Merkel cells.
• Langerhans cells.

Question 5

What proportion of the epidermis is keratinocytes and melanocytes?

Answer 5

• Keratinocytes = 90%.

- Melanocytes = 8%.

Question 6

What is the function of keratinocytes?

Answer 6

Produce keratin = makes skin waterproof.

Question 7

What is the function of melanocytes?

Answer 7

Produce the pigment melanin.

Question 8

What is the function of merkel cells?

Answer 8

Act as sensory receptors.

Question 9

What is the function of langerhans cells?

Answer 9

Are involved in immune response.

Question 10

Where is the stratum corneum found?

Answer 10

In the epidermis.

Question 11

What does melanin do?

Answer 11

Contributes to skin colour and protects from UV light.

Question 12

What are the physical properties of the epidermis?

Answer 12

• Protect the warm, moist internal environment.

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Question 13

Where is keratinocytes formed?

Answer 13

Stratum basale.

Question 14

How do keratinocytes divide?

Answer 14

By mitosis.

Question 15

What happens as keratinocytes mature?

Answer 15

• Change shape.
• Lose their nucleus.
• Form flattened dead cells filled with keratin.

Question 16

What is keratin?

Answer 16

Hard protein that makes up our nails and hair.

Question 17

What helps keep the epidermis intact in healthy skin?

Answer 17

Balance of water and lipid content.

Question 18

What is sebum?

Answer 18

• Oily substance containing antimicrobial agent.

- Mixture of lipids = helps keep the skin hydrated.

Question 19

What is an antimicrobial?

Answer 19

An agent that kills microorganisms/inhibits their growth.

Question 20

What are the cells in the dermis?

Answer 20

• Fibroblasts.
• Mast cells.
• Phagocytes.
• Lymphocytes.

Question 21

What is the function of fibroblasts?

Answer 21

Secrete collagen and elastin.

Question 22

What is the function of mast cells?

Answer 22

• Play a key role in non-specific immune responses.

- Secrete inflammatory mediators.

Question 23

What is the function of phagocytes?

Answer 23

Destroy bacteria by a process of ‘cell eating’.

Question 24

What is it called when phagocytes destroy bacteria?

Answer 24

Phagocytosis.

Question 25

What is the function of lymphocytes?

Answer 25

• White blood cell involved in immune surveillance.

- Involved in specific immune response.

Question 26

What does the dermis contain?

Answer 26

• Lymph vessels.
• Nerve endings.
• Hair follicles.
• Glands.

Question 27

What are the properties of the dermis?

Answer 27

• Store water (hydration).
• Dense connective tissue.
• Collagen = tensile strength + support.
• Elastin fibres = toughness + flexibility.

Question 28

How does a blister form?

Answer 28

Dermis separates from the epidermis –> tissue fluid builds up between the layers.