Integumentary System Lecture

A complete set of vocabulary flashcards covering the anatomy, histology, cellular components, accessory structures, pathology, and burns associated with the human integumentary system.

Epidermis

The outermost skin layer composed of stratified squamous epithelium, consisting of 4 to 5 layers depending on friction.

Stratum basale (Stratum germinativum)

The bottom-most layer of the epidermis, 1 to 2 cell layers thick, actively mitotic due to proximity to the dermal blood supply, and containing melanocytes.

Stratum spinosum

An epidermal layer made of 8 to 10 closely fitting cell layers that appear prickly, capable of mitosis, and considered part of the stratum germinativum.

Stratum granulosum

A layer of the epidermis comprising 3 to 5 layers of flattened cells containing keratin with nuclei in various stages of degeneration, undergoing no mitosis.

Stratum lucidum

An epidermal layer of clear, flat, dead cells found only in the thick skin of the soles and palms, containing the protein eleidin which transforms into keratin.

Stratum corneum

The uppermost epidermal layer containing 25 to 30 layers of flat, dead cells filled with keratin (cornified) that continuously shed and replace, serving as a barrier against bacteria, light, heat, and chemicals.

Keratinocytes

Epidermal cells that produce keratin and protect the body from water loss.

Melanocytes

Epidermal cells located in the stratum basale that produce melanin to shield the body from ultraviolet radiation.

Dermis

The thickest layer of the skin that contains collagen and elastic fibers, nerve fibers, blood vessels, sweat and sebaceous glands, and hair follicles.

Papillary layer

The upper 20% of the dermis consisting of loose connective tissue with elastic fibers, sweat glands, and dermal papillae that increase friction.

Reticular layer

The deeper dermal layer composed of dense irregular tissue with elastic and collagenous fibers, highly vascularized, where hair follicles, nerves, and sweat glands originate.

Hypodermis (Subcutaneous layer)

Also known as superficial fascia, a subcutaneous layer composed of adipose and areolar tissue that anchors skin to underlying organs, acts as an insulator, shock absorber, and energy store.

Melanin

A pigment produced by melanocytes in the stratum basale ranging in color from pale to dark brown, which increases with UV exposure and protects against skin cancer.

Carotene

An orange pigment found in the stratum corneum and dermis that contributes to skin coloration.

Albinism

A genetic condition characterized by a total lack of melanin, resulting in unpigmented skin, hair, and eyes.

Basal cell carcinoma

The least malignant and most common type of skin cancer with a 99% cure rate, treated by liquid nitrogen or surgical excision.

Squamous cell carcinoma

Skin cancer arising from keratinocytes in the stratum spinosum, treated via surgical removal and potentially radiation therapy.

Malignant melanoma

The most dangerous form of skin cancer that affects melanocytes, representing 5% of skin cancer cases, with about 1/3 developing from moles.

ABCDE of skin cancer

A clinical screening guide for skin cancer: A for Asymmetrical, B for Border, C for Color, D for Diameter, and E for Evolution.

Arrector pili muscle

A muscle attached to each hair follicle that pulls the hair upright to generate gooseflesh.

Eccrine sweat glands

Ordinary sweat glands distributed across the body that secrete a watery sweat directly onto the skin surface to cool the body.

Apocrine sweat glands

Larger, less numerous sweat glands found in the groin and armpits that secrete a cloudy white substance into hair follicles; bacterial breakdown of this sweat causes body odor.

Sebaceous glands

Glands that secrete sebum, an oily lipid mixture, into hair follicles to lubricate skin and hair, inhibit bacterial growth, and cause acne when blocked.

Ceruminous glands

Modified cutaneous glands that produce cerumen (earwax) to entrap foreign substances and shield the ear.

Mammary glands

Accessory glands that produce and secrete milk.

Nail matrix

The hidden pocket beneath the skin at the nail base that generates new cells, which harden with keratin and push forward to form the nail plate.

First degree burn

A superficial burn limited to epidermal damage, characterized by red, dry, painful skin that heals easily without leaving a scar.

Second degree burn

A partial-thickness burn causing epidermal and dermal damage, resulting in red, wet, very painful, blistered skin that may leave scars.

Third degree burn

A full-thickness burn destroying the epidermis, dermis, and hypodermis, often injuring deeper muscle and bone; appears dry, waxy, or charred and requires skin grafts.