Integumentary System Course Study Guide

Integumentary System ● Functions of the skin ○ A covering for the underlying tissues, protecting them from dehydration, injury, and germ invasion. ○ Helps regulate body temperature by controlling the size of the blood vessels in the dermal layer of the skin. ○ Helps manufacture vitamin D. The ultraviolet light on the skin is necessary for the first stages of vitamin D formation. ○ The site for many nerve endings ■ A square inch contains 72ft of nerves and hundreds of receptors. ○ Has tissues for the temporary storage of fat, glucose, water, and salts. Most of these substances are eventually absorbed by the blood and transported to other parts of the body. ○ Serves to reduce the harmful radiation contained in everyday sunlight. ○ Has special properties that allow it to absorb drugs and many other chemical substances. ● Structure of the skin ○ Epidermis ■ The outermost layer of the skin; made up of epithelial cells, with no blood vessels present whatsoever. ○ Dermis ■ Known as “true skin” it is made up of connective tissue and it contains some blood vessels. ○ Subcutaneous ■ The fat layer of the skin ● Skin color as indicator of disease ○ Redness ■ Erythema ● Causes dilation of capillary network ● Fever, allergic reaction, and inflammation ○ Bluish tint (grayish in darker skin tones) ■ Cyanosis ● Causes a decrease in oxygen in capillaries ● Heart or respiratory disease ○ Yellow ■ Jaundice ● accumulation of bile in capillaries ● Gallbladder or liver disease ○ Pallor ■ Constriction of capillaries or decrease in red blood cells ■ Emotional stress or anemia ● Hair ○ Root ■ The part of the hair that is implanted in the skin ○ Shaft ■ The hair that projects from the skin’s surface ○ Hair follicle ■ The root embedded in an impocketing of the epidermis ○ Alopecia ■ A genetic predisposition that causes permanent baldness in some people. ● Disease conditions and nail color ○ Liver disease ■ White nails ○ Kidney disease ■ Half of nail is pink, other half is white ○ Heart condition ■ Nail bed is red ○ Lung disease ■ Yellow and thickening nails ○ Anemia ■ Pale nail bed ○ Diabetes ■ Yellowish with a slight blush at the base ○ Hypoxia ■ Bluish nails ● Disorders of the skin ○ Acne vulgaris ■ (acne) is a common non contagious and chronic disorder of the sebaceous glands ○ Dermatitis ■ A non contagious inflammation of the skin ○ Eczema ■ An acute or chronic non contagious inflammatory skin disease ○ Impetigo ■ An acute inflammatory and contagious skin disease seen in babies and young children. ■ Characterized by appearance of vesicles that rupture and develop distinct yellow crust ○ Psoriasis ■ A chronic non contagious inflammatory autoimmune skin disease characterized by the development of dry reddish patches covered with silvery-white scales. ○ Ringworm ■ A highly contagious fungal infection marked by raised, itchy, circular patches with crusts. ○ Urticaria (hives) ■ A non contagious skin condition recognized by the appearance of intensely itching wheals or welts. ○ Herpes simplex ■ Occurs around the face and mouth ■ Spreads through oral contact ○ Genital herpes ■ Another form of the herpes virus ■ May appear as a blister in the genital area ● Skin cancer ○ Associated with exposure to ultraviolet light ○ Most common type of cancer in people ○ Basal cell carcinoma ■ The most common and least malignant type of skin cancer ■ Usually occurs on the face ■ Full recovery occurs in 99% of the cases ○ Squamous cell carcinoma ■ Arises from the epidermis and occurs most often on the scalp and lower lip ■ This type grows rapidly and metastasizes to the lymph nodes ■ Chances for recovery are good only if found early ○ Malignant melanoma ■ Occurs in pigmented cells of the skin called melanocytes ■ Metastasizes to other areas quickly ■ A color or size change in a mole or wart may indicate this type ■ The 5 year survival rate is 91% ● Burns ○ Traumatic injuries that result from exposure to radiation from the sun, heat lamp, contact with boiling water, steam, fire, chemicals, or even electricity. ○ Rule of nines ■ Used to measure the percent of the body burned. ■ The body is divided into 11 areas and each area accounts for 9% of the total body surface. ■ Each arm is 4.5%, perineal area is 1%, each leg is 9%, etc… ○ First degree (superficial) burns ■ Involves only the epidermis ■ Sunburns are usually in this category ■ May include swelling, redness, and pain ■ Hold burned area under cool running water for 10-15 min ■ Healing occurs within a week ○ Second degree (partial-thickness) burn ■ May involve the epidermis and dermis ■ Include pain, swelling, redness, and blistering ■ Pain medication and dry sterile dressing applied to open skin areas ■ Healing occurs within 2 weeks ○ Third degree (full-thickness) burn ■ Involves complete destruction of the epidermis, dermis, and subcutaneous layers. ■ Loss of skin, eschar (blackened skin), no pain because the nerve endings are possibly destroyed ■ Immediate hospitalization is advised ■ Skin graft is done as soon as possible