Skin

Front 1

Skin

Back 1

Outer covering of the body.
Largest organ in the integumentary system.

Front 2

Functions of the skin:

Back 2

1. Protection (barrier against pathogens, and damage from external environment).
2. Sensation (nerve endings)
3. Heat regulation - blood supply to skin helps control loss or conservation of heat
4. Evaporation
5. Storage and synthesis - lipids, vitamin D
6. Excretion - urea
7. Absorption - oxygen, medicine, etc.
8. Water resistance

Front 3

Structure of the skin

Back 3

Epidermis - surface layer
Dermis - connective tissue (also smooth muscle, nervous tissue)
Hypodermis NOT part of skin - adipose connective tissue

Front 4

What type of epithelium is the epidermis?

Back 4

Keratinised stratified squamous epithelium

Front 5

Cell types in epidermis:

Back 5

- Keratinocyte
- Melanocyte
- Langerhans cells
- Merkel cells
- Stem cells in basal layer

Front 6

Keratinocyte

Back 6

- Make up 90% of cells in epidermis
- Provide barrier agains external environment
- Protect agains light, heat, water, chemicals, bacteria, etc.
- Produce keratin, lipds
- Take up melanin from melanocytes

Front 7

Melanocytes

Back 7

- Produce melanin
- Melanin is transferred to keratinocytes in melanosome granules
- Provides protection from UV light

Front 8

Dermis
- components
- cell types
- function

Back 8

- Main component is connective tissue
- Cell types include fibroblasts, adipocytes & macrophages
- A lot of extracellular material, including collagen and elastic fibres
- Blood vessels
- Cutaneous sensation: sensory receptors and nerves

Front 9

Which structures of skin are involved in thermoregulation and how?

Back 9

The dermis contains blood vessels - heat is lost through the blood vessels primarily.

Front 10

How is vitamin D synthesised?

Back 10

- UV light breaks covalent bond in cholesterol in skin
- Subsequent steps in liver and kidney
- Involved in calcium homeostasis