INTEGUMENTARY SYSTEM

Celeste Roderno-Desingaño

Integumentary System

The largest organ system

This includes the skin and its appendages

Function: (1) serve to waterproof, cushion and protect the deeper tissues; (2) excrete wastes; (3) regulate temperature, (4) attachment site for sensory receptors to detect pain, sensation, pressure and temperature, and (4) storage of water, fat, glucose and Vitamin D

In humans, the integumentary system additionally provides Vitamin D synthesis.

The top layer of skin made up of epithelial cells.

Does not contain blood vessels

Function: for protection, absorption of nutrients and homeostasis

Structure: keratinized stratified squamous epithelium

EPIDERMIS

Layers of the Epidermis1. Stratum basale single layer of cells resting on a

basement membrane Cells of this layer divide

continuously2. Stratum spinosum Consists of spiny prickle cells that

interlock to support the skin3. Stratum granulosum Middle layer that initiates

keratinization4. Stratum lucidum Protects skin against ultraviolet rays

damage Thick layer appears only in

frequently used areas such as palms of the hands and soles of the feet.

5. Stratum corneum Outermost layer with rows of dead

cells. Protects the underlying cells from

drying out.

The middle layer of the skin, composed of loose collective tissues such as collagen with elastin arranged in a diffusely bundled and woven pattern.

The dermal layer provides a site for the endings of blood vessels and nerves.

Many chromatophores are also stored in this layer as bases of integumental structures such as hair, feathers and glands (sweat and oil).

DERMIS

HYPODERMIS Subcutaneous layer,

superficial fascia or subdermis

Physiological function:

(1) Insulation;

(2) storage of energy;

(3) aid in anchoring the skin and

(4) gives extra protection against trauma.

Diseases and Disorders

Albinism – a condition where skin does not produce melanin

Athlete’s foot (tinea pedis) – common fungus infection in which the skin between the toes becomes itchy and sore, cracking and peeling away.

Acne – skin disease marked by pimples on the face, chest and back.

Burns – these are injuries to tissues caused by intense heat, electricity, UV radiation or certain acids

Wart – small growth caused by a viral infection of the skin. This is contagious.

Chronic paronychia –One nail folds but often spreads to several others. Nails become tender from time to time and sometimes a little thick pus can be expressed from under the cuticle.