Path 2 Diseases of the Integumentary System

What is the largest organ of the body?

The skin

What is the most superficial layer of the skin?

The epidermis

What layer is directly beneath the epidermis?

The dermis

What is the deepest layer of the skin?

The hypodermis

How is skin related to mucous membranes?

It is continuous with but structurally distinct from them

What does the epidermis contain?

Melanin, hemoglobin, carotene, and keratin proteins

What structures are found in the dermis?

Blood vessels, sweat glands, and hair shafts

What are the two types of sweat glands?

Eccrine and apocrine glands

Where are eccrine glands located and what do they do?

All over the body; they open onto the skin's surface

Where are apocrine glands located and what do they do?

In the axilla and genital region; they open into hair follicles

What do sebaceous glands secrete?

Sebum

Where are sebaceous glands located?

All over the body; they open into hair follicles

What is a lesion?

A circumscribed area of pathologically altered tissue; an injury or wound

What is an abscess?

A localized accumulation of pus

What causes an abscess?

Usually a bacterial infection

What are symptoms of an abscess?

Pain, swelling, loss of function; may be local or spread

What is necrosis?

Pathological death of cells, tissues, or organs in a living body

What is an ulcer?

An open sore or lesion with sloughing of inflamed necrotic tissue

What is a decubitus ulcer?

A bedsore caused by tissue compression and lack of blood flow

What is acne?

A clogged hair follicle forming a blackhead, whitehead, or pimple

What causes acne?

Excess oil, bacteria, and dead skin cells

Is acne inflammatory?

Yes

Who is typically affected by long-term acne?

Men (long-term); women (often hormonal)

What is a vesicle?

A blister-like elevation of skin containing serous fluid

What is serous fluid?

A lubricant-like fluid found in body spaces like the pleura

What is a pustule?

A small elevation of the skin containing pus

What is a skin boil?

A pus-filled infection of a hair follicle

What is a carbuncle?

A group of connected boils with discharge of pus and dead tissue

What is a furuncle?

An abscess in a sweat gland or hair follicle

What is a cyst?

A closed sac with a definite wall that contains fluid, semi-fluid, or solid material

What is a sebaceous cyst?

A fluid-filled sac just under the skin

What causes syphilis?

Treponema pallidum bacteria

What is a chancre and when does it appear?

An ulcer at the site of exposure in primary syphilis; appears 2-3 weeks after exposure

What occurs in secondary syphilis?

Ulcers on mucous membranes and a reddish-brown rash (syphilid) on the palms and soles

When does secondary syphilis occur?

3-12 weeks after the chancre heals

What is a gumma?

A tertiary syphilis ulcer with necrotic center and surrounding inflammation

When does tertiary syphilis develop?

Over a year after exposure

What is congenital syphilis?

A form of syphilis in newborns causing rashes and lesions within 4-8 weeks of birth

What is seborrheic dermatitis?

An inflammatory skin condition of the scalp, ranging from dandruff to thick crust

What are possible causes of seborrheic dermatitis?

Fungal infection, AIDS, other conditions

Is seborrheic dermatitis contagious?

No

What is eczema?

An inflammatory skin condition that causes dry, itchy patches

What is atopic dermatitis?

A chronic form of eczema with dry patches

What is contact dermatitis?

An inflammatory skin reaction to an irritant

What is psoriasis?

A chronic condition causing thick, scaly skin patches

What is plaque psoriasis?

Causes large plaques of dry, scaly tissue

What is nail psoriasis?

Causes abnormal nail growth and nail separation from the bed

Do psoriasis and eczema occur in flare-ups?

Yes

What is a melanocytic nevus?

A mole or birthmark

What is melanoma?

A dangerous skin cancer of the melanocytes

What is squamous cell carcinoma?

Cancer of squamous cells in the epidermis and hollow organ linings

What is basal cell carcinoma?

Cancer of the basal cells in the deepest layer of the epidermis

What is dry gangrene?

Necrosis from lack of oxygenated blood

What is gas gangrene?

Necrosis with gas formation caused by Clostridium perfringens

What is moist (wet) gangrene?

Swollen, red tissue due to poor venous drainage

What is ecchymosis?

Superficial bleeding under the skin; a bruise

What is petechia?

A pinpoint, extravascular blood discoloration

What is purpura?

Subcutaneous bleeding causing purple patches

What skin-related conditions may be present postmortem?

Discolorations, dehydration, lesions, pigmentation changes, swelling

What are examples of postmortem discolorations?

Jaundice, cyanosis, and carbon monoxide poisoning

What may be required due to postmortem conditions?

Restorative work