Integumentary System

Structure, functions and appendages Disorders of the skin: burns, moles, other problems

INTEGUMENTARY SYSTEM

Includes skin covering surface of body and specialized derivatives of skin such as nails, hair, sebaceous & sweat glands.

Functions of skin 1) Protection of underlying

tissues2) Prevents desiccation3) Provides insulation (hair and feathers)4) Increases heat loss by changes in hair or feather position or by increased evaporative water loss (sweating)5) Reception of tactile, thermal or pain stimuli6) Removal of excess water and salts7) Production of vitamin D

Structure of the skin

Normal skin is composed of two layers: the epidermis (outermost layer), the dermis (middle layer), and below is hypodermis (innermost layer). The layered nature of the skin results from a vertical arrangement of the different types of cells.

Skin Structure

Two primary layers:epidermis – outermost

dermis – deeper and thicker of the two

Under the two primary layers is the hypodermis (subcutaneous layer)

Integumentary System

Commonly called the skin,  it enwraps the body and serves several purposes: 

• offers protection (first line of defense) to the underlying layers from the sun, infection,  harmful chemicals, cut and tears

• serves in body temperature regulation almost 3000 calories of body heat per day

•   sense organ activity respond to temperature, touch, pressure, and pain 

Temperature Regulation

The integumentary system aids in homeostasis (the bodies natural temperature regulation) by providing a barrier against cold air.  Skin also blocks breezes, water, snow, etc. from entering the body.  Thus the body is able to stay warmer.  However unlike a typical man-made jacket, which also provides protection against the elements your skin is completely breathable.  The pores in skin allow the entrance of certain useful molecules, but not harmful ones.

Hair

Our skin is able to sense insects on the skin before they are able to sting. The hair on the head serves to control and prevent heat loss as well as guard against sunlight and physical trauma. Hair is produced by hair follicles in the skin. These follicles are heavily vascularized and are surrounded by nerve fibers. Goose bumps occur when small muscles pull the follicles upright producing a bump on the surface of the skin.

Sweat Glands

Sweat glands are distributed throughout the skin. Their basic function is to cool the body. This is accomplished by evaporation. Evaporation of sweat off of the body dissipates body heat.

Pigmentation

Three pigments determine skin color: melanin, carotene, and hemoglobin. However, only melanin is made in the skin. Melanin can be gradated into many different shades. It is this ability of Melanin that gives different races different skin coloration.

Melanin

A special type of cells known as melanocytes produces melanin. Melanocytes are primarily found in the stratum germinativum. Whenever the skin has had an exposure to sunlight, the stratum germinativum cells, phagocytize or eat the skin pigment melanin. After an amount of time, melanin accumulates within the stratum germinativum cells, and tends to form a protective pigment "umbrella.” These “umbrellas” of melanin pigment shields DNA from the damaging effects of ultraviolet radiation.

Skin Cancer

When there is a lack of melanin, the DNA, or RNA, will be in direct contact with ultraviolet radiation, which can cause cancer or another type of adverse impact upon the skin.

Carotene and Hemoglobin

Carotene has a yellow-orange color and is primarily found in the palms and the soles. Hemoglobin gives fair-skinned people a pink hue to their skin due to the lack of melanin in the epidermis, which makes it almost transparent.

•Asymmetry of shape: one half does not look like the other •Border is irregular: scalloped, notched, discontinuous •Color is uneven: multiple shades ranging from white to tan to brown to black occasionally some red as well •Diameter is larger than 6mm in most cases •Enlargement: gradual increase in size and elevation

Malignant Melanoma

• a proliferation of markedly atypical melanocytes with the potential for dermal invasion and widespread metastasis

• several clinical subtypes have been described, but the prognosis for all subtypes depends on the histologic thickness (Breslow level) of the tumor

• sun exposure is an important predisposing factor,

• most lesions arise de novo, but some arise from "precursor lesions" such as large congenital nevi or "dysplastic" nevi

Basal Cell Carcinoma: clinical •most common human cancer: more than 400,000 new patients annually •found most commonly on sun-exposed areas of fair-skinned, sun-damaged individuals •translucent, "pearly" or "waxy" papule; associated telangiectasia, sometimes central ulceration •locally destructive, very rarely metastasizes; can cause death •sun-exposure, ionizing radiation, immunosuppression are all predisposing factors •several clinical and histologic subtypes

                        

 

Squamous Cell Carcinoma •malignant tumor of epithelial keratinocytes – skin and mucous membranes •induced by various carcinogens, but in the skin SUN EXPOSURE is the most common •ionizing radiation, oncogenic viruses such as certain wart viruses, arsenic ingestion, chronic wounds also induced cutaneous SCC •usually arises as solitary, keratotic or eroded, pink papule or nodule – persists and grows •may arise from a precancerous actinic keratosis •SCC arising in sun-damaged skin less prone to metastasis than mucosal SCC

            

Burns: rule of nines An injury to the layers of the skin by fire, chemicals,

electricity, steam, and radiation.

• 1st degree burn is when the top layer of skin or, epidermis, is slightly burned, producing pain and redness

• 2nd degree burns injure the second layer of skin called the dermis and result in redness, pain, and blisters.

• 3rd degree burns damage involves all layers of the skin, which appears charred black, and could be dry and white in some spots.

                                     

Rule of nines

This method divides the body into eleven specific sections, each of which comprise approximately 9%, or multiples of 9%, of the patient’s body surface area.  These areas are the head and neck, the front of the chest, the front of the abdomen, the posterior chest or upper back, the posterior abdomen or lower back, the anterior surface of each lower extremity, the posterior surface of each lower extremity, and each upper extremity. The genitalia account for the remaining one percent.

The first method, and the one that is used most in the prehospital setting, is the rule of nines. This method divides the body into eleven specific sections, each of which comprise approximately 9%, or multiples of 9%, of the patient’s body surface area.  These areas are the head and neck, the front of the chest, the front of the abdomen, the posterior chest or upper back, the posterior abdomen or lower back, the anterior surface of each lower extremity, the posterior surface of each lower extremity, and each upper extremity. The genitalia account for the remaining one percent.

Burns

• normal - fig. 1• 1st degree – fig. 2• 2nd degree – fig. 3• 3rd degree –fig. 4                                                   

First Aid for burns

For most burns:• Calm and reassure the

victim.• Dowse area with cool

water. Do not apply ice.• Remove any constricting

clothing and jewelry, if it comes off easily.

• Never use butter, oils, or ointments on severe burns.

According to the Burn Unit, there are five categories of burn depth. They are •first-degree•second-degree partial thickness •second-degree deep partial thickness•third-degree full thickness•fourth-degree full thickness.

First-degree and most second-degree burns

• Flush or soak the burn in cool water for several minutes.

• For minor burns, apply antibacterial ointment after the burn has cooled.

• Cover the burn with a sterile bandage or clean cloth.

• If necessary, give the person pain medication such as acetaminophen or ibuprofen.

• Seek medical attention if the burn is more than 2 to 3 inches in diameter.

Third-degree burns -including electrical burns

• Make sure the victim is breathing and begin CPR if necessary. See CPR for more information.

• Call 911 immediately • To prevent shock, lay the victim

flat, elevate the feet about 12 inches, and cover with a coat or blanket.

Chemical burns

• Flush chemicals thoroughly for 15 to 30 minutes with water.

• Remove contaminated clothing, if possible.

• Do not attempt to neutralize the burn with a reciprocal chemical.

• Call 911 immediately.

Three layersA/B Epidermis = upper layer,

ectodermal origin; specialized epithelium composed of stratified squamous, can be thick or thin depending on stresses on that area of skin, can also be keratinized or nonkeratinized

C Dermis = below epidermis, mesodermal origin, dense irregular CT, thicker than epidermis; sensory endings (tactile, thermal, pain) found throughout underlies dermis, areolar to adipose CT, connects skin to structures underneath

Appendages

A. epidermisB. dermisC. SubcutaneousD. vascular tissueE. sebaceous glandsF. hair hair follicle - root, shaft, bulbG. receptors, H. sweat glands

References

“Current Concepts In Burn Therapy,”Ken Forinash, BS, NREMT-PEMS Coordinator, Cunningham Fire Protection District, Denver, COwww.vfre.com/Presentation20/