Skin Structure The Dermis

Skin cross-section

The Dermis This layer is found directly underneath the epidermis Made up of 2 layers: Papillary Reticular The dermis has a supportive role to play Made up of connective tissue closely packed together Has a higher water content

The Papillary Layer The higher of the 2 layers Contains small tubes called capillaries which carry blood & lymph Nerve endings can also be found in this layer inc touch, pain, cold & heat The function of this layer is to provide “food” to the living layers of the epidermis

The Reticular Layer Found below the papillary layer Collagen and elastin fibres found here which are responsible for the elasticity and general tone of the skin. Sweat glands, sebaceous glands and the arrector pili muscle are found here Pressure nerve endings can also be found in this layer.

What else would I find? Arrector pili muscle Small muscles attached to the hair follicle. When cold these muscles contract, making the hairs stand on end “goose bumps”. Air is trapped between the skin and the hair warming the body

Sweat Glands Eccrine sweat gland found all over the body sweat duct opens directly onto the skin (pore) mixture of water, salts & toxins

Apocrine sweat gland Found in the underarm, groin & nipple areas Secrete a milky substance These glands are larger than eccrine and are attached to hair follicles Controlled by hormones so do not become active until puberty Body odour is caused by bacteria breaking down this type of sweat

Sebaceous glands Small, sac like structures producing sebum Sebum is a fatty substance and acts as the skin’s natural moisturiser Glands are found all over the body Hormones control their activity Sebum production decreases as we age Mixes with sweat to produce the acid mantle, pH 5.5-5.6

Nerve Endings Sensory nerve endings Found all over the body especially fingertips and lip area The nerves make us aware of touch, pain, pressure, heat/cold Messages are sent from these nerves to the brain

Motor nerve endings These receive messages from the brain and carry them around the body Motor nerves stimulate an action/response e.g. muscle contraction, sweat glands, sebaceous gland

Blood vessels These vessels make sure the skin gets the oxygen and nutrients it needs to live Waste products such as carbon dioxide and metabolic waste are removed

Subcutaneous Layer Found under the dermis Can also be called the hypodermis Consists of adipose tissue (fat) and areolar tissue Adipose tissue – major energy reserve, supports & protects against injury. Acts as an insulator – helps keep you warm Areolar tissue contains collagen & elastin fibres making this layer elastic and flexible Generally thicker in women than men