Integumentary System: Physiology and Pathophysiology of the Integumentary System

Functions of the Skin

• Protection from pathogens and UV light

• Vitamin D production

• Temperature regulation

• Water retention

• Sensation

• Nonverbal communication

Regeneration

normal function returns as stratum basale cells reach contact inhibition before the fibroblasts fill the area with scar tissue

Fibrosis

normal functioning tissue is replaced by scar tissue as fibroblasts’ collagen fibers produce granulation tissue to fill in the wound’s clot and reach contact inhibition before the cells of the stratum basale

First Degree Burn

involve the epidermis; symptoms: redness, pain, swelling

Second Degree Burn

involve the epidermis and dermis; include redness, pain, swelling, and blisters

Third Degree Burns

involve the epidermis, dermis, and hypodermis; symptoms include charring and no pain at the burn site

Rule of Nines

uses estimation of the body regions to determine the extent of a burn

sebaceous and sweat glands

Effects of Aging: Loss of ____________________ in the dermis

melanocytes

Effects of Aging: Loss of _________ causing uneven tanning and age spots.

sagging and wrinkling

Effects of Aging: Dermis thins and the number of collagen and elastic fibers is reduced which along with gravity, causes _______________________ of the skin.

fragile

Effects of Aging: Blood vessels become more ___________ and are less efficient in regulating temperature.

bruises

Aging: Bumps that lead to _________ are more frequent because of thinner dermis.

thins

Effects of Aging: Nail plate and matrix _________

gray

Effects of Aging: Hair thins and turns ______ due to the loss of melanocytes.

Skin Cancer

most common cancer, and it is associated with sun exposure

Basal Cell Carcinoma

most common skin cancer and it tends not to metastasize

Squamous Cell Carcinoma

results from keratinocytes in the stratum spinosum; commonly form on the face, ears, and neck and can metastasize

Malignant Melanoma

rarest form of skin cancer; most deadly because it metastasizes easily; usually begins in a mole

Skin infections

skin is infected by a type of bacteria, virus, fungus, or parasite

Impetigo

caused by the bacterium Staphylococcus or Streptococcus; appears as a cluster of vesicles that burst and crust over, which may cause pain and itching

Cellulitis

infection of the skin’s dermis or hypodermis and is frequently caused by Streptococcus or Staphylococcus bacteria that commonly occurs on the face and lower legs, characterized by redness and swelling of an area of the skin that increases in size rapidly

Warts

growth caused by human papilloma virus (HPV)

Herpes Simplex Virus (HSV)

contagious viral infection characterized by small, painful blisters that appears on the skin and on the mucous membranes of the mouth or genital area

Herpes Varicella Zoster

causes chicken pox and shingels

Tinea Infections

communicable through contact with an infected person, damp surfaces, characterized by a circular rash that clears from the center, giving it a ringlike appearance; includes ringworm, athlete’s foot, and jock itch

Scabies

parasitic skin infections caused by an infestation of mites which caused small red bumps on the skin that itch severely

Psoriasis

autoimmune disorder characterized by an overgrowth of skin cells and improper keratinization of the epidermis and nails

Atopic Dermatitis/Atopic Eczema

allergic reaction that causes an infection resulting in a leathery discolored appearance

Hives/Urticaria

skin reaction that can be caused by insect bites or by contact with substances that can cause an allergic reaction, symptoms include raised areas of the skin, redness, and itching

Scleroderma

excess collagen causes hardening of the skin and organs, with decreased elasticity; this leads to a decrease in function caused by exposure to chemicals/autoimmune diseases such as lupus

Skin biopsy

diagnostic test characterized by the removal of a piece of tissue or a sample of cells from a body so that it can be analyzed in a laboratory

Skin Scraping

diagnostic test characterized by the taking of skin cell scrapings so that the cells can be viewed under the microscope

Wood’s Light Test

diagnostic test characterized by the use of a black light to view pigment changes in the skin

Skin Patch Test

diagnostic test characterized by applying small amounts of substances to test for allergic reactions

Dermoscopy

diagnostic test characterized by using a hand-held device called a dermatoscope to diagnose skin lesions

Tzanck Test

diagnostic test characterized by examining the fluid from a blister to check for herpes simplex or herpes zoster