The Integumentary System A.Components of the system B.Factors that influence rate and degree of aging 1.Heredity 2.Diet 3.Occupational/recreational choices

The Integumentary System

A. Components of the system

B. Factors that influence rate and degree of aging

1. Heredity

2. Diet

3. Occupational/recreational choices

a. Sun (photoaging)

b. Wind

4. Hormones


C. Structure of the skin

1. Epidermis

a. Stratified squamous epithelium

b. Keratinizing system (keratin)

c. Pigmentary system (melanin)

2. Dermis

a. Papillary layer

b. Reticular layer

3. Hypodermis

E

D

H

D. Glands of the skin

1. Sudoriferous glands

a. Types

2. Sebaceous glands


i. Eccrine glands

ii. Apocrine glands

b. Functions

a. Sebum (skin oil)

b. Functions

E. Functions of the skin

1. Protective barrier

2. Vitamin D formation

3. Thermoregulation

4. Cutaneous sensations

5. Excretion

6. Immunity


F. Age-related changes

1. Most are not life-threatening, but may affect self-image and therefore attitude and general health

2. Epidermal changes

a. Thinner (exfoliation vs. mitosis)

b. Increased permeability (?)

c. Decreased melanocytes (What are age spots?)

d. Decreased immune cells



3. Dermal changes

a. Reduced number of fibroblasts and fibers


i. Thins and becomes translucent

ii. Collagen becomes larger and more coarse, reducing space available for fat storage

b. Cross-linking of elastin

c. Atrophy of glands

d. Decreased blood flow

e. Decreased number and activity of hair follicles

f. Changes in sensory receptors


4. Hypodermal changes = loss of fat, leading to:

a. Increased wrinkles

b. Emaciated appearance

c. Loss of padding (coupled with loss of blood supply bed sores)

d. Loss of thermal insulation


G. Age-related dysfunctions

1. Lentigo (len-ti’-go)

a. AKA = senile freckles

b. Dark brown, irregular flat areas on dorsum of hands, forearms, and face

c. Result from increased melanin deposition (not age spots)

d. Generally benign, but should be watched


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2. Senile purpura (pur’-pu-rah)

a. Irregularly shaped red-purple patches

b. Usually on forearm and dorsum of hand

c. Bruises formed by leaked blood from weakened capillaries

d. Fade over period of weeks, but replaced by others


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3. Senile angiomas

a. 75% of people over 70 have them

b. Elevated clusters of dilated capillaries

c. Appear as red spots from very tiny to ¼ inch

d. May be found anywhere on the body

e. Not dangerous


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4. Acrochondron (ak-ro-cor’-don)

a. AKA = skin tags

b. Small pendulous skin growths containing dermal tissue and blood vessels

c. Resemble small benign tumors

d. Particularly found on chest, neck, eyelids, armpits (particularly on women)


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5. Senile pruritus (pru-ri’-tus)

a. Loss of glandular activity results in dry, less pliant skin that may develop tiny cracks

b. Cracks cause the itching (pruritis)

c. Left untended, the cracks widen and lead to exudate

d. External factors that dry the skin exacerbate problem



6. Senile (actinic) keratosis

a. Localized fat, red skin areas that gradually thicken, become scaley, and yellow-brown

b. Associated with sun exposure

c. Regenerates if peeled off

d. Can be precancerous squamous cell carcinoma


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7. Seborrheic (seb-o-re’-ik) keratosis

a. Benign epidermal tumors

b. Usually found on the scalp, face, neck, and back

c. Begin as flesh-colored raised plaque with flat top; turns brown-black

d. Has a greasy, scaley, wart-like crust on surface


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8. Shingles (Herpes zoster)

a. Peak incidence between 50 – 70 years

b. Must have had chickenpox first (Herpes varicella)

c. Virus lies dormant in sensory neurons

d. Once reactivated (often by stress), person itches and aches along affected dermatome(s)

e. Small red papules appear with 3 days, first on the back

f. Vesicular eruptions can be painful


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9. Decubitus ulcers (pressure or bed sores)

a. Cavities of dead tissue

b. Generally seen in immobilized persons

c. Occurs over bony prominences that are in constant contact with a surface

d. Caused by occluded blood supply (anoxic necrosis)

e. Very prone to infection and hard to heal


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10.Skin cancer

a. Epidermal, dermal, glandular

b. Malignant vs. benign

c. Any new growth or any change in preexisting growths (warts, moles) should be watched

d. Early detection = cure

e. Melanomic vs. nonmelanomic tumors



10.Skin cancer

f. types


i. Basal cell carcinoma

ii. Squamous cell carcinoma

iii. Malignant melanoma

iv. Secondary skin cancers

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H. Take home messages

1. Internal and external factors affect the skin

2. Skin becomes thinner, less elastic, dryer

3. Less subcutaneous fats

4. Decreasing pigment cells, but increasing pigmentation

5. Changes in hair and nails

6. Many potential dysfunctions

7. All skin growths should be monitored


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The Integumentary System A.Components of the system B.Factors that influence rate and degree of aging 1.Heredity 2.Diet 3.Occupational/recreational choices