Medical Terminology: The Integumentary System

1. What is The Integumentary System?
The outside covering of the body, or the skin, serves three major purposes. It prevents dehydration, regulates body temperature, and is the major deterrent of infection in the body. When this barrier is broken, whether by surgical incision, wound, cut, or scrape, the primary defense is no longer intact.
Superficial breaks in the skin may be treated on an outpatient basis. However, deeper wounds, and those involving the face and neck, may need more intense care with IV antibiotics. Skin is composed of several layers and is waterproof. Many skin manifestations are described using common terms.
Macules are small, flat-topped lesions, <1. cm in diameter, similar to a freckle. Papules are elevated lesions, also <1. cm in diameter. A wheal is a raised area filled with fluid and usually temporary, such as in hives.
A vesicle is a fluid-filled blister, often seen in shingles. Bullae are >1. cm in diameter and are fluid-filled blisters. A plaque is >1. cm in diameter, raised, and shallow.
A nodule is a solid lesion, up to 1. cm in diameter with depth. A tumor is >1. cm in diameter, and is solid with depth. A pustule is an elevation containing purulent material. Petechiae are <1. cm in diameter and are usually round areas of deposits of blood. A purpura is a large petechia.

2. Burns
Burns are damage to the skin and body tissues caused by flames, heat, cold, friction, radiation (sunburn), chemicals, or electricity. Burns are generally divided into three categories, depending on the damage.
A first-degree burn occurs with injury to the outer layer of skin called the epidermis. It is red and painful with some swelling.
A second-degree burn occurs when the epidermis is burned, as well as the next layer, the dermis. Severe pain, white and reddened areas, swelling, blisters, and perhaps drainage are seen.
A third-degree burn goes through all the layers of the skin and could involve underlying tissues. It is often painless because of destruction of the nerves in the area. The area looks black (termed eschar) and/or reddened.
Many drugs may make the skin more sensitive to the sun, producing the effect of sunburn with little exposure. Common medications with this effect include: amiodarone, carbamazepine, furosemide, naproxen, oral contraceptives, piroxicam, quinidine, quinolones, sulfonamides, sulfonylureas, tetracyclines, and thiazides, among others.

3. Dermatitis
Dermatitis is inflammation of the skin as a result of contact with an irritating substance such as a chemical, foreign substance, medication, or contact with a plant such as poison ivy. The skin may become reddened, irritated, and itchy.
The usual causes are allergic reactions. Often the patient has a history or a family history of asthma, allergy, or eczema. Some later symptoms may be the result of scratching of the skin. Often the cause may be a drug reaction, the body’s immune system reacting to a medication.

4. Skin Cancers
Cancer of the skin is the most common type of cancer. The incidence of skin cancer is one of the fastest growing. Early detection is of the utmost importance because a cure is obtainable in the early stages.
Heredity may also be a factor. Skin cancer is usually divided into three major subtypes:
. Basal Cell: Most common
. Squamous Cell: Second most common
. Melanoma: Most fearsome
Basal cell carcinomas are directly related to sun damage, with most lesions occurring in sun-exposed areas. This type recurs frequently. Squamous cell carcinomas are often caused by sun exposure, may be difficult to distinguish from some changes in the skin, and spread more readily. Melanoma is the most deadly form of skin cancer; it usually occurs on the face or upper back. A mnemonic to aid in remembering melanoma characteristics may be helpful:
A—asymmetric shape
B—borders that are irregular
C—change in color
D—diameter larger than a pencil eraser
E—ever changing

5. Cellulitis
Cellulitis is an infection of the skin, caused by bacteria that enter the skin through an opening. The legs are the most common site of cellulitis, although it may occur anywhere that bacteria enter. The most common bacteria are Streptococcus Staphylococcus.
Bacteria may enter through fissures in the feet from fungal infections, through cracks in dry skin, from insect bites, or cuts from shaving. The elderly, immunocompromised patients, and patients with lymphedema, diabetes, or poor circulation are at greatest risk.

6. Pressure Ulcers
A pressure ulcer starts on the skin and often progresses to deeper tissue; it is caused by impaired circulation to the tissue from pressure over a period of time. Without adequate blood flow and the nutrition it brings, the tissue die. Those often affected are confined to a wheelchair or bed, and unable to move themselves, not reducing the pressure frequently enough. It can take as little as a few hours in one position for a stage 1. pressure ulcer to develop. The usual sites of pressure ulcers, or bedsores, are on bony prominences, such as the buttocks, sacrum, heels, knees, and hips.
Friction from linens can impair the integrity of the skin, as can the shear force, when the skin moves in one direction and the deeper structures do not move. Assessment tools are available to predict the risk of pressure ulcers developing. A commonly used scale is the Braden scale, which includes such criteria as friction, the nutritional status of the patient, mobility and activity levels, moisture exposure of the skin, and any limitations of sensory perception.

7. Wounds and Healing
A wound is any break in the skin. It may be intentional, as with surgery, or unintentional, as a result of trauma. Types of wounds include surgical, penetrating (such as a knife), crushing, burn, lacerations, bites (human, animal), ulcers, and pressure ulcers. Immediately after a wound occurs, inflammation occurs with platelet aggregation. Next, leukocytes travel to the area for infection surveillance.
A proliferative phase starts when the epidermal cells move toward the wound, and cover the approximated wound edges, usually by the third day. The fibroblastic phase occurs with collagen and fibroblasts forming a scar. Wound healing occurs in various ways. Primary intention happens when edges are closely approximated and new tissue, or granulation, knits the close edges together.
Wound healing by secondary intention occurs in a larger wound in which the edges are farther apart. This is often intentional when the wound is infected, dirty, or from a bite. The granulation tissue builds across the surface of the wound forming a large clot and sequentially, a larger scar.

Basic Questions
Integumentary System

1. What is the purpose of skin?
The outside covering of the body, or the skin, serves three major purposes. It prevents dehydration, regulates body temperature, and is the major deterrent of infection in the body.

2. What are macules?
Macules are small, flat-topped lesions, <1. cm in diameter, similar to a freckle.

3. What are papules?
Papules are elevated lesions, also <1. cm in diameter.

4. What is a wheal?
A wheal is a raised area filled with fluid and is usually temporary, such as in hives.

5. What is a vesicle?
A vesicle is a fluid-filled blister, often seen in shingles.

6. What are bullae?
Bullae are >1. cm in diameter and are fluid-filled blisters.

7. What is plaque?
A plaque is >1. cm in diameter, raised, and shallow.

8. What is a nodule?
A nodule is a solid lesion, up to 1. cm in diameter with depth.

9. What is a pustule?
A pustule is an elevation containing purulent material.

10. What are petechiae?
Petechiae are <1. cm in diameter and are usually round areas of deposits of blood.

11. What is a purpura?
A purpura is a large petechia.

12. What are burns?
Burns are damage to the skin and body tissues caused by flames, heat, cold, friction, radiation (sunburn), chemicals, or electricity. Burns are generally divided into three categories, depending on the damage.

13. What is a second-degree burn?
A second-degree burn occurs when the epidermis is burned, as well as the next layer, the dermis. Severe pain, white and reddened areas, swelling, blisters, and perhaps drainage are seen.

14. What is a third-degree burn?
A third-degree burn goes through all the layers of the skin and could involve underlying tissues. It is often painless because of destruction of the nerves in the area.

15. What is eschar?
Eschar is the area of burned skin in a third-degree burn that looks black.

16. What causes basal cell carcinomas?
Basal cell carcinomas are directly related to sun damage, with most lesions occurring in sun-exposed areas.

17. What are squamous cell carcinomas?
Squamous cell carcinomas are often caused by sun exposure, may be difficult to distinguish from some changes in the skin, and spread more readily.

18. What is melanoma?
Melanoma is the most deadly form of skin cancer; it usually occurs on the face or upper back.

19. What are characteristics of a melanoma?
A—asymmetric shape
B—borders that are irregular
C—change in color
D—diameter larger than a pencil eraser
E—ever changing

20. What is cellulitis?
Cellulitis is an infection of the skin, caused by bacteria that enter the skin through an opening.

21. What causes a pressure ulcer?
A pressure ulcer starts on the skin and often progresses to deeper tissue; it is caused by impaired circulation to the tissue from pressure over a period of time. Without adequate blood flow and the nutrition it brings, the tissue will die.

22. What is the Braden scale?
The Braden scale is a commonly used scale that includes such criteria as friction, the nutritional status of the patient, mobility and activity levels, moisture exposure of the skin, and any limitations of sensory perception.

23. What is a wound?
A wound is any break in the skin.

24. What is the proliferative phase of wound healing?
The proliferative phase starts when the epidermal cells move toward the wound, and cover the approximated wound edges, usually by the third day.

25. What is the fibroblastic phase of wound healing?
The fibroblastic phase occurs with collagen and fibroblasts forming a scar.