Integumentary System Notes

These notes are about aging skin.

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1.      Epidermis

a.       Keratin -> barrier to microbes, chemicals, water, trauma

1.      AGING -> (1) slightly thinner and uneven -> barrier (chemicals);
(2) weaker and looser ->
barrier (microbes, chemicals), scaly appearance
(3) slower production -> slower healing ->
barrier (microbes, water, chemicals, trauma)

b.      Melanin -> barrier to light

1.      AGING -> (1) less, slower production -> barrier to light -> sunburn, skin cancer, wrinkling, immune response
(2) uneven distribution -> cosmetic problems ( age spots )

c.       Langerhans cells -> barrier (start immune responses against microbes, chemicals), fights skin cancer

1.      AGING -> (1) decreased numbers -> immune response -> defense (microbes, chemicals, cancer) and allergic responses ( discomfort, warning of danger {microbes, chemicals}

d.      Hair -> shade, thermal insulation, cushion, filter, touch sensation

1.      AGING -> fewer; thinner; rougher; color; altered distribution, baldness, in hair on face, chin, lips; in eyebrows, ears, nostrils) -> most functions in most areas {some exceptions} and altered cosmetic effect {mostly worse effect}

e.       Nails -> protect from trauma; used as tools

1.      AGING -> weaker, slower growth, less clear, rougher -> protection, worse cosmetic effect, nail infections

 

2.      Dermis

a.      Barrier

1.      cross-linked collagen -> stiffness - traumatic injury

2.      enzymes weaken collagen -> traumatic injury

3.      fibroblast functioning -> slower healing

4.      WBCs and macrophages -> immune response

5.      vessels -> inflammation

6.      vessels -> weaker skin and slower healing

b.      Information

1.      WBCs, macrophages, mast cells -> immune response, inflammation

2.      vessels -> inflammation

3.      touch and pressure receptors -> sensation

c.       Temperature regulation

1.      vessels and slower vessel response -> temp. regulation (for heat & cold)

2.      sweat glands and sweat gland functioning -> temp. regulation (for heat)

d.      Vitamin D production

1.      slower cells and reactions -> vitamin D production

2.      water and fiber cross-links -> trapped vitamin D

3.      vessels -> supply of raw materials and removal of vitamin D

e.      Cosmetic effects

1.      irregularity and binding of elastin -> sagging, wrinkling

2.      water -> sagging, wrinkling

3.      vessels -> paleness

4.      sebum production -> roughness of skin and luster of hair

 

3.      Boundary between the epidermis and the dermis

a.       number of connections by keratinocytes

b.      number and size of dermal papillae

c.       EFFECTS = service of epidermis, separation of epidermis and dermis -> healing, pain, infection, gripping by fingerprints

 

4.      Subcutaneous layer

a.       thinning fat, water in gel -> cushioning -> injury from trauma

b.      thinning fat -> insulation -> temp. regulation

 

5.      Skin diseases

    a. increased occurrence and severity with increasing age

 

6.      Sunlight

a.       increased production of and damage from free radicals

b.      production of irregular keratinocytes -> skin cancer

c.       patchy distribution of melanocytes -> age spots

d.      Langerhans cells -> infection, skin cancer, warning from inflammation

e.       irregularities in elastin -> sagging and wrinkling

f.        blood vessels -> inflammation for warning, temp. regulation, vitamin D production and removal

g.       thicker capillary walls -> exchange for epidermis, dermis, vitamin D production and removal

h.       enlarged sebaceous glands -> adverse cosmetic effects (i.e., blackheads)

i.        Prevention

1.      avoid exposure

2.      wear protective clothing

3.      use sunscreen lotions

4.      use anti-oxidant lotions

j.        Treatment

1.      Tretinoin.

(a)    reduces sun damage

(b)   reveres cosmetic effects from sun damage

(c)    reverses sun damage to collagen, vessels, and the junction between the epidermis and dermis

2.      Skin peals and abrasion

3.      Laser treatment

4.      Moisturizers

 

7.      Heat

a.       production of irregular keratinocytes -> skin cancer

b.      patchy distribution of melanocytes -> age spots

c.       Langerhans cells -> infection, skin cancer, warning from inflammation

d.      blood vessels -> inflammation for warning, temp. regulation, vitamin D production and removal

e.       thicker capillary walls -> exchange for epidermis, dermis, vitamin D production and removal

f.        enlarged sebaceous glands -> adverse cosmetic effects (i.e., blackheads)

 

8.      Decubitus ulcers

a.       immobility; age changes weaken skin; thinner fat layer; circulatory diseases (e.g., atherosclerosis); nutrition; skin hygiene; exercise; diseases (e.g., atherosclerosis, diabetes)

b.      infection; pain; adverse cosmetic effect

 

9.      Neoplasia

a.      benign

1.      cosmetic; risk of skin injury; discomfort; risk of infection

b.      malignant

1.      cosmetic; infection; damage other organs

c.       Prevention

1.      skin care; sunlight; remain active; good nutrition; regular evaluation and corrective measures; exposure to harmful factors (microbes, trauma, burns, chemicals); avoid or treat other diseases (e.g., atherosclerosis, diabetes)

 

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    © Copyright 2000 - Augustine G. DiGiovanna - All rights reserved.
This material MAY be reproduced or distributed in any form or by any means, or stored in any data
base or retrieval system ONLY under one of the following two conditions: (1) If no individual, group,
organization, institution, company, corporation or other entity is charged for its use and only for use by
instructors and students in courses where students are required to purchase the book HUMAN
AGING: BIOLOGICAL PERSPECTIVES by Augustine G. DiGiovanna, The McGraw-Hill
Companies, New York, 1994 or 2000; (2) If prior written permission is obtained from Augustine G.
DiGiovanna, Ph.D., Salisbury University  - agdigiovanna@Salisbury.edu