Flashcards Anatomy and Skin Functions

Epidermis

Superficial region of the skin; made of epithelial tissue.

Dermis

Deeper region of skin; mostly fibrous connective tissue.

Hypodermis

Subcutaneous layer beneath the skin; mostly adipose tissue.

Keratinocytes

Produce keratin; most common epidermal cells.

Melanocytes

Produce melanin and protect against UV damage.

Dendritic cells

Help activate the immune system.

Merkel cells

Sensory touch receptors.

Stratum corneum

Most superficial epidermal layer; made mostly of dead, keratin-filled cells.

Stratum lucidum

Clear layer found only in thick skin.

Stratum granulosum

Layer where cells undergo keratinization.

Stratum spinosum

Layer containing keratinocytes connected by desmosomes.

Stratum basale

Deepest epidermal layer; contains actively dividing stem cells.

Epidermal layer order

Corneum → Lucidum → Granulosum → Spinosum → Basale.

Papillary layer

Superficial dermis; contains areolar connective tissue and dermal papillae.

Reticular layer

Deep dermis; makes up about 80% of the dermis.

Dermal papillae

Create friction ridges and fingerprints.

Collagen fibers

Provide strength and resiliency.

Elastic fibers

Allow stretch and recoil.

Cleavage lines

Directions in which collagen fibers run parallel to the skin surface.

Melanin

Pigment produced by melanocytes; protects against UV radiation.

Carotene

Yellow-orange pigment.

Hemoglobin

Gives fair skin a pinkish color.

Cyanosis

Blue skin caused by low oxygenation.

Erythema

Redness of the skin.

Pallor

Blanching or pale skin.

Jaundice

Yellowish skin caused by excess bilirubin.

Hair matrix

Actively dividing area that produces hair.

Hair papilla

Provides blood supply to the hair.

Arrector pili

Muscle responsible for goose bumps.

Root hair plexus

Sensory nerve endings that detect touch.

Vellus hair

Fine, pale body hair.

Terminal hair

Coarse, long hair found on areas such as the scalp and eyebrows.

Nail matrix

Responsible for nail growth.

Eccrine sweat glands

Produce sweat and help regulate body temperature.

Apocrine sweat glands

Found mainly in axillary and anogenital areas; begin functioning at puberty.

Sebaceous glands

Produce sebum.

Sebum

Oily secretion that softens skin and hair and has bactericidal properties.

Integumentary system functions

Protection, temperature regulation, sensation, metabolic functions, blood reservoir, and excretion.

Basal cell carcinoma

Most common and least malignant skin cancer.

Squamous cell carcinoma

Skin cancer involving keratinocytes of the stratum spinosum.

Melanoma

Cancer of melanocytes; highly metastatic.

ABCD rule

Asymmetry, Border irregularity, Color, Diameter.

First-degree burn

Epidermis only; redness, swelling, and pain.

Second-degree burn

Epidermis and upper dermis; blisters.

Third-degree burn

Entire thickness of skin; nerve endings may be destroyed.

Rule of Nines

Estimates the extent of burns and fluid loss.

Vitiligo

Loss of melanocyte activity in patches of skin.

Hypertrichosis

Abnormal growth of terminal hair.

Blood reservoir

The skin can hold up to about 5% of the body's blood volume.

Cutaneous sensation

The skin detects temperature, touch, and pain.

Vitamin D function

The skin synthesizes a vitamin D precursor.

Sweat function

Helps regulate body temperature and excretes salts and nitrogenous wastes.

Skin protection

Provides chemical, physical, and biological barriers.