The Integumentary System

Skin- An aggregation of tissues that performs a certain function (organ). Carries out a specialized function Occupies (3000sq in) in area.

The Functions of the Skin 1. Regulate Body Temperature- Accomplished by glands(sweat= cooling) …blood flow can also change temperature. 2. Protection- Physical Barrier, protects from abrasion, bacteria, dehydration, and UV rays. 3. Reception of Stimuli- Sensitive to temperature, touch, pressure, pain. 4. Excretion- Releases; water, salts, etc. 5. Synthesis Vitamin D- Produces the most active form of Vitamin D. 6. Immunity- Cells of the skin are involved in Immune response; Langerhans & Granstein cells.

Layers of the Skin Epidermis Dermis Hypodermis

The Epidermis Three main types of cells make up the Epidermis. Kerationocytes- waterproofs the skin. Melanocytes- responsible for skin color. Nonpigmented Granular Dendrocytes- Involved in immune response. Langerhans Cells Granstein Cells The 5 Layers of the Epidermis 1. Stratum Basale 2. Stratum Spinosum 3. Stratum Granulosum 4. Stratum Lucidum 5. Stratum Corneum

The Dermis Very thick on palm of hand and sole of feet. Contains numerous blood vessels, nerves, glands, and hair follicles. Two divisions of the Dermis 1. Papillary Region Contains Fraction Ridges, form fingerprint. 2. Reticular Region Strength, Extensibility, Elasticity Striae- Silver/White streaks, stretch marks.

The Hypodermis Layer of areolar and adipose tissue under the dermis. Allows the other layer to anchor to the body.

Skin Color The color of skin is due to pigment(melanin) in the skin, and the amount varies from person to person (pale, yellow, black). Albinism- Absence of pigment. Vitiligo- Patchy white spots due to loss of pigment. Freckles- Concentration of pigment (melanin) in patches in the skin.

Accessory Structures Hair-Protects from heat and foreign objects. Nail- Plates of tightly packed, hard cells of the epidermis. Glands- Oil, Sweat, Wax

Injuries or Trauma to the Integumentary System Injuries to the intergumentary system are very common. These injuries are open wounds( breaks in epithelium).

Injuries or Trauma to the Integumentary System Abrasion- Results from scraping against a solid object, bleeding can be slight.

Injuries or Trauma to the Integumentary System Incision- Linear cut produced by sharp objects, bleeding can be severe if deep vessels are damaged. Laceration- Jagged, Irregular tear in the skin’s surface, bleeding can be severe, lacerations are prone to infection. Puncture- Results from slender, pointed object piercing the epithelium. Little bleeding. Avulsion- A chunk of tissue torn away by brute force, considerable bleeding, more serious injuries are possible.