Chapter 4 Integumentary System

Strata of the epidermis from deepest to most superficial:

  1. Stratum Basale

  2. Stratum Spinosum

  3. Stratum Granulosum

  4. Stratum Lucidum(thick,hairless skin only)

  5. Stratum Corneum

Stratum Basale- Lies closest to the dermis, is connected to it along a wavy border that resembles corrugated cardboard. Cells undergo mitosis, and daughter cells are pushed upward to become the more superficial layer

Stratum Spinosum/Stratum Granulosum- Cells become more keratinized and increasingly flatter

Stratum Lucidium- Formed by dead cells of the deeper strata, only on the soles of feet and palms of hands, thick, and hairless skin only

Stratum Corneum- Outermost of epidermis, shingle-like dead cells are filled with keratin(protective protein prevents water loss from skin)

Cutaneous Membrane(Skin)- dry, outermost protective boundary

Serous Membrane(serosae)- lines compartments in the ventral body cavity that are lcosed to the exterior of the body

Mucous Membrane(mucosae)- moist, lines all body cavities that open to the exterior body surface

Decubitis Ulcers- Bedridden patients who are not regularly turned or dragged/pulled across the bed repeatedly

Acne- active infection of the sebaceous glands

If the accumulated material dries, it darkens, forming a blackhead

If the accumulated material doesn’t dry or darken it forms a whitehead

Seborrhea(cradle caps)- In infants, is caused by overactivity of the sebaceous glands

Athletes Foot- itchy, red, peeling condition of the skin between the toes, resulting from an infection

Boils- inflammation of hair follicles and surrounding tissues, commonly on the dorsal neck

Carbuncles- clusters of boils often caused by the bacterium Staphylococcus aureus

Cold Sores(severe blisters)- small fluid-filled blisters that itch and sting, caused by human herpesvirus 1 infection

Contact Dermititis- Itching, redness, and swelling of the skin, progressing to blistering

Impetigo- Pink, fluid-filled, raised lesions that develop a yellow crust and eventually rupture and weep fluid

Psoriasis- reddened epidermal lesions covered with dry, silvery scales that itch, burn, crack, and sometimes bleed

First degree burn- superficial epidermis is damaged, red and swollen, not serious, heals in a few days

Second degree burn(partial thickness)- Epidermis and superficial of the dermis, red, painful, and blistered, regeneration of the epithelium

Third degree burn- Destroys the epidermis and dermis , sometimes the subcutaneous tissue, blisters are usually present, area appears blanched or blackened, regeneration is not possible, grafting must be done\

Fourth degree burn(full thickness)- Extend into deeper tissues such as bones, muscles, and tendons, appear dry and leathery.

A- Assymetry

B- Border

C- Color

D- Diameter

E- Evolution

Basal Cell Carcinoma- least malignant cancer, most common skin cancer, cells of the stratum basale, altered so that they cannot form keratin, no longer honor the boundary between epidermis and dermis

Squamous Cell Carcinoma- arises from the cells of the stratum spinosum, lesions appear as scaly, reddened papules (small, rounded swellings), gradually form shallow ulcers with firm, raised borders

Malignant Melanoma- cancer of melanocytes, accounts for only 5 percent of skin cancer, often deadly, arises from accumulated DNA damage in a skin cell and usually appears as a spreading brown to black patch that metastasizes rapidly to surrounding lymph and blood vessels