Ch. 7 Dermatology

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R313 Medical Terminology
Ch. 7 Dermatology
Dermatology
The anatomy and physiology of the
Integumentary System.
The diagnostic tests, medical and surgical
procedures used to treat integumentary
diseases and conditions.
Anatomy and Physiology
Integumentary System:
skin (epidermis and dermis)
sebaceous glands
sweat glands
hair
nails
Function: protects the body and is the first line of
defense against invading microorganisms; the sense
of touch.
Anatomy
Skin layers:
1. Epidermis
2. Dermis
3. Subcutaneous
Characteristics of the Epidermis:
-epithelial tissue
-covers the external surface of the body and mucous
membranes.
-outer epidermis is the corneal layer.
-lower epidermis is the basal layer.
-external cells contain keratin, protein that gives skin
a waterproofing ability.
-cells also contain melanocytes that produce
melanin, a protein pigment that gives skin its color;
absorbs UV light from the sun.
-dead cells are removed through a process called
exfoliation.
Figure 7-2 Epidermis and dermis
Characteristics of the Dermis:
-Connective Tissue
-Thicker layer than the epidermis
-Contains collagen fibers (firm, white protein) and
elastin fibers (elastic, yellow protein).
-Contains: blood vessles
neurons (nerve cells)
hair follicles
sebaceous glands (oil glands; secrete sebum)
sweat glands (sudoriferous glands; secrete
water, sodium, waste products)
-Has dermatome’s: specific area on the skin that
sends sensory information to the spinal cord.
Hair
-Covers most of the body.
-Additional facial, axillary, and pubic hairs appear
during puberty.
-Contains melanocytes and keratin.
-Forms in a hair follicle in the dermis.
-Piloerection
Xie Qiuping
Hair Length = 18’ 5.54”
Tran Van Hay
Hair Length = 20’ 3.6”
Nails
-Cover and protect the distal ends of the fingers and
toes.
-Each nail consists of a nail plate, nail bed, cuticle,
lunula, and nail root.
Characteristics of the Subcutaneous Tissue
-Loose, connective tissue directly beneath the
dermis of the skin.
-Composed of adipose tissue that contains lipocytes
(fat-storing cells).
-Provides a layer of insulation to conserve internal
body heat.
-Acts as a cushion to protect the bones and internal
organs.
Physiology of an Allergic Reaction
-An allergy or allergic reaction is a hypersensitivity
response to certain types of antigens known as allergens.
Allergens:
foods
pollens
molds
animal dander
dust
chemicals
drugs
-The basis of all allergic reactions is the release
of histamine from basophils in the blood and
mast cells in the connective tissue.
-A local reaction occurs when an allergen
touches the skin or mucous membranes.
-Anaphylaxis is a severe systemic allergic
reaction that can be life-threatening.
(anaphylactic shock)
Epi-pen
Diseases & Conditions
-Dermatitis
-Edema
-Hemorrhage
petechiae
contusion (bruise)
ecchymosis (large contusion)
hematoma
Skin Lesions
Neoplasm- benign or malignant growth
occurring on the skin.
Pruritus- itching
Rash
Wound
Xeroderma- excessive dryness of the skin
Skin Color Conditions:
Albinism- lack of pigment because of a genetic mutation.
Cyanosis- bluish-purplish discoloration of the skin.
Erythema- reddish discoloration of the skin.
Jaundice- yellowing of the skin; liver cannot process bilirubin.
Necrosis- blackish discoloration of the skin.
Pallor- paleness due to lack of blood supply.
Vitiligo- autoimmune disease where the melanocytes are destroyed
causing white patches.
Figure 7-7 Necrosis and pallo
Meyer/Custom Medical Stock Photo, Inc.
Skin Injuries:
Abrasion
Blister
Callus (corn)
Burn Types
1st Degree Burns:
-a burn that affects the epidermis only,
causing erythema without blistering.
2nd Degree Burns:
-a burn that affects the epidermis and the dermis, classified as superficial
(involving the epidermis and the papillary dermis) or deep (extending into the
reticular dermis). Called also partial thickness burn.
3rd Degree Burns:
-a burn that destroys both the epidermis and the dermis, often also involving the
subcutaneous tissue. Called also full-thickness burn
4th Degree Burns:
-a burn that extends deeply into the subcutaneous tissue; it may involve muscle,
fascia, or bone.
First Degree Burn
Second Degree Burn
Third Degree Burn
Fourth Degree Burn
Cicatrix- collagen scar tissue; keloid scar tissue
formed from an overproduction of collagen.
Decubitus Ulcer (bed sore)
Excoriation- scratch on the skin
Laceration- deep wound
Skin Infections:
Abscess- local pus containing pocket
Cellulitis- inflammation and infection of the connective
tissues.
Herpes- caused by a virus
Type 1- lips (cold sores)
Type 2- HSV; sexually transmitted (genital herpes)
Herpes Whitlow- infection at the base of the
fingernail
Herpes Varicella Roster- skin rash; chickenpox; adult
version is called Shingles.
Figure 7-13 Shingles
Gill/Custom Medical Stock Photo, Inc.
Tinea- fungal infection (ringworm, jock itch,
athletes’s foot)
Verruca (warts)- skin lesion caused by the
human papillomavirus on the hands, fingers, or
feet.
Skin Infestations:
Pediculosis- lice
Scabies- parasitic mites
Allergic Skin Conditions:
Contact Dermatitis- reaction caused by an
allergen coming in contact with the skin.
Urticaria- hives, wheal & welts.
Benign Skin Markings and Neoplasms:
Actinic Keratoses- raised, dry, rough areas of the skin.
Freckle- grouping of melanocytes from sun exposure.
Hemangioma- growth of superficial blood vessels.
Nevus- birth marks
Papilloma- small protrusion of epidermis and dermis.
Premalignant Skin Lesions- abnormal skin lesions that are not
yet cancerous.
Senile Lentigo- light to dark brown macules from exposure to
the sun. (sun spots)
Syndactyly- webbed fingers or toes; polydactyly is extra
fingers or toes.
Xanthoma- benign growth that is a yellow nodule or plaque
on the hands, elbows, knees, or feet.
Malignant Neoplasms of the Skin:
Cancer- malignant
Basal Cell Carcinoma- most common type
Malignant Melanoma- can spread to other parts of
the body.
A- asymmetry
B- border
C- color
D- diameter
Squamous Cell Carcinoma
Kaposi’s Sarcoma- skin cancer that begins in the
connective tissue or lymph nodes. Common in
AIDS patients.
Autoimmune Diseases with Skin Symptoms:
Psoriasis- excessive number of epidermal cells;
causes redness and itching; scales and plaque.
Scleroderma- skin and internal organs progressively
harden due to deposits of collagen.
Systemic Lupus Erythematosus (SLE)- deterioration
of the collagen in the skin and connective tissues;
joint pain, sun sensitivity, fatigue.
Figure 7-22 Psoriasis
NMSB/Custom Medical Stock Photo, Inc.
Diseases of the Sebaceous Glands:
Acne Vulgaris- during puberty, sebaceous glands
secrete large amounts of sebum.
Acne Rosacea- middle-aged patients, sebaceous
glands secrete large amounts of sebum, causes
blotchy redness and edema.
Seborrhea- overproduction of sebum at times other
than puberty; also called cradle cap in infants and
eczema in adults.
Diseases of the Sweat Glands:
Anhidrosis- absence of sweat glands.
Diaphoresis- profuse sweating.
Diseases of the Hair:
Alopecia- chronic loss of scalp hair.
Folliculitis- infection of the hair follicle; often occurs after
shaving.
Hirsutism- presence of excessive, dark hair on the
forearms and over the lip of women.
Pilonidal Sinus- abnormal passageway that begins as a
large, abnormal hair follicle that contains a hair that is
never shed.
Diseases of the Nails:
Clubbing- abnormally curved fingernails and
stunted growth of fingers.
Onychomycosis- fungal infection of the
fingernails or toenails.
Paronychia- bacterial infection of the skin next
to the cuticle.
Laboratory and Diagnostic Procedures:
Allergy Skin Testing
Culture and Sensitivity (C & S)- test done on pus of a
bacteria infection to determine course of treatment.
RAST- blood test done to determine allergies.
Skin Scraping- sampling of skin taken to be observed in
determining if a patient has ringworm.
Tzanck Test- skin scraping done to test fluid for the
presence of a virus.
Wood’s Lamp- UV light used to highlight areas of the skin
in a darkened room.
Medical and Surgical Procedures:
Botox Injections- the drug
Botox is injected into the
skin to paralyze the muscle.
Collagen Injections- collagen is a protein, helps
to plump the skin to reduce wrinkles and
scarring.
Cryosurgery- liquid nitrogen is put onto a wart or mole to
remove it.
Curettage- a tool called a curet is used to remove a
superficial skin lesion.
Debridement- procedure to remove necrotic tissue from
a burn, wound, or ulcer.
Electrosurgery- electricity is used to remove a nevus,
wart, or small malignant lesion.
Incision and Drainage- a scalpel is used to make a cut to
drain infection from an abscess or cyst.
Laser Surgery- a laser is used to remove birthmarks,
tattoos, enlarged blood vessels, or hair.
Skin Examination- examining a patient’s skin.
Skin Resurfacing- removal of acne scars, tattoo’s,
wrinkles.
Chemical Peel- use a chemical to remove the outer layers
of the epidermis.
Dermabrasion- removal of the outer epidermal layers
using a spinning wire brush or diamond surface.
Laser Skin Resurfacing- use of a laser to remove
outer layers of the epidermis and/or dermis.
Microdermabrasion- skin resurfacing done using
aluminum oxide crystals.
Suturing- use of sutures to bring edges of skin
together to allow for better healing.
Surgical Procedures:
Biopsy- procedure done to remove a skin lesion for
testing and diagnosis.
Excisional Biopsy- use of a scalpel to remove a skin
lesion.
Incisional Biopsy- uses of a scalpel to remove part
of a skin lesion.
Needle Aspiration- use of a needle to remove cells
for testing from a skin lesion.
Punch Biopsy- circular metal cutter is used to
remove a plug shaped core of skin.
Shave Biopsy- use of a razor blade to shave of a
skin lesion.
Dermatoplasty- any type of
plastic surgery of the skin.
Liposuction- produce used to
remove excess adipose tissue.
Mohs’ Surgery- procedure used to remove skin
cancer.
Rhytidectomy- also called a facelift; done to
tighten up loose skin and remove wrinkles.
Skin Grafting:
Autograft- skin graft taken
from the patient’s own body.
Allograft- skin graft taken from a cadaver.
Xenograft- skin graft taken from an animal (pig).
Synthetic Skin Graft- artificial skin made from
collagen; new skin grows replacing the collagen.

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