Unit 4.1 - Skin, Hair, and Nails

Skin

Epidermis: very thin, tough outer layer of the skin

Dermis: thicker inside layer of skin

Epidermis

Stratum Corneum: exposed top portion; constantly shed

Stratum Germinativum: innermost layer; constantly reproducing

Dermis

Contains:

collagen for strength and elastic fibres for flexibility.

blood vessels, nerves, sensory receptors, lymphatics.

accessory organs (hair, sweat and sebaceous glands).

Subcutaneous

Hypodermis (adipose tissue)

Stabilizes skin in relation to underlying tissues.

Hair

Velus Hairs: peach fuzz found mostly everywhere

Terminal Hairs: thicker hair found on certain areas of the body

Glands

Sebaceous Glands: oil glands that lubricate the hair and skin

Sweat Glands: excretes waste, cools skin, provides protection

Eccrine: “everywhere”

Apocrine: active after puberty where there are terminal hairs

Nails

Protects tip of fingers/toes.

Nail plate can alter with diseases.

Assess Skin

Skin should be even across the body.

Colour: pallor, erythema (fever), cyanosis (late sign of little oxygen), jaundice (breakdown of blood cells).

Moisture: diaphoresis (profuse sweating), dehydration (leads to dry skin).

Texture and Thickness: should be smooth, firm, and uniformly thin.

Mobility and Turgor: pinch back of hand, if skin remains upright (tenting) sign of dehydration.

Lesions: Asymmetry, Border, Colour, Diameter, Elevation and Evolution.

Concerning if lesion is asymmetrical, has an irregular or indistinct border, has multiple colours, is greater than 6mm, or is raised/uneven.

Assess Nails

Profile Sign: hold up index finger and see if angle of nail sticks straight out (angle greater than 180° indicates clubbing)

Consistency: note any pits or grooves.

Colours: should be pink in colour.

Capillary Refill: how long it takes colour to return to nail bed.