Chapter 5

The Integumentary System

Part C 5.9

5.9 Skin Cancer and Burns

Skin can develop over 1000 different conditions and ailments

Many internal diseases ______themselves on skin

Most common disorders are ______

Less common, but more damaging, are:

–Skin cancer

–Burns

Skin Cancer

Most skin tumors are ______(not cancerous) and donot spread (______)

Risk factors

–______to UV radiation

–Frequent ______of skin

Some skin lotions contain ______that can repair damaged DNA

Three major types of skin cancer

–Basal cell carcinoma

–Squamous cell carcinoma

–Melanoma

Basal cell carcinoma

–Least ______and most common

–Stratum basale cells proliferate and slowly invade dermis and hypodermis

–Cured by ______in 99% of cases

Squamous cell carcinoma

–______most common type; can metastasize

–Involves keratinocytes of stratum spinosum

–Usually is a scaly reddened papule on scalp, ears, lower lip, or hands

–Good prognosis if treated by radiation therapy or removed surgically

Melanoma

–Cancer of melanocytes; is most ______type because it is highly metastatic and resistant to chemotherapy

–Treated by wide surgical excision accompanied by immunotherapy

Melanoma(cont’d)

–Key to survival is early detection:ABCDE rule

A: ______; the two sides of the pigmented area do not match
B: ______irregularity; exhibits indentations
C: ______; contains several colors (black, brown, tan, sometimes red or blue)
D: ______; larger than 6 mm (size of pencil eraser)
E: ______; changing over time

Burns

Tissue damage caused by ______, ______, ______, or certain ______

Immediate threat is ______and electrolyte imbalance

To evaluate burns, the Rule of Nines is used

–Body is broken into 11 sections, with each section representing 9% of body surface (except genitals, which account for 1%)

Burns can be classified by severity

–First-degree

______damage only
–Localized redness, edema (swelling), and pain

–Second-degree

______and upper ______damage
–Blisters appear
–First- and second-degree burns are referred to as partial-thickness burns because only the epidermis and upper dermis are involved

–Third-degree

Entire ______(referred to as full-thickness burns
Skin color turns gray-white, cherry red, or blackened
No edema is seen and area is ______because nerve endings are destroyed
Skin ______usually necessary

Burns are considered critical if:

–_____% of body has second-degree burns

–_____% of body has third-degree burns

–______, ______, or ______bear third-degree burns

Treatment includes:

–______(removal) of burned skin

–______

–Temporary ______

–______

Developmental Aspects of theIntegumentary System

Fetal: by end of 4th month, skin of fetus is developed

–Lanugo coat: delicate hairs in 5th and 6th month

–Vernix caseosa: sebaceous gland secretion that protects skin of fetus while in watery amniotic fluid

Developmental Aspects of theIntegumentary System

Infancy to adulthood: skin thickens and accumulates more subcutaneous fat; sweat and sebaceous gland activity increases, leading to acne

–Optimal appearance during 20s and 30s

–After age 30, effects of cumulative environmental assaults start to show

–Scaling and dermatitis become more common

Developmental Aspects of theIntegumentary System

Aging skin

–Epidermal replacement slows; skin becomes thin, dry, and itchy (decreased sebaceous gland activity)

–Subcutaneous fat and elasticity decrease, leading to cold intolerance and wrinkles

–Increased risk of cancer due to decreased numbers of melanocytes and dendritic cells

–Hair thinning

Ways to delay aging:

–UV protection, good nutrition, lots of fluids, good hygiene

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