Integumentary System Flashcards

Flashcards covering vocabulary related to the integumentary system based on the lecture notes.

Integumentary System

The outermost system of the body, made up of the skin and its derivatives (glands, hair, and nails), which covers and protects the body.

Epidermis

The thin, outer layer of the skin made of epithelial tissue; avascular, receiving nutrients via diffusion from the dermis.

Dermis

The thicker, inner layer of the skin made of fibrous connective tissue; vascularized, receiving nutrients from the bloodstream.

Hypodermis

Also called the subcutaneous layer, located below the dermis, made predominantly of adipose tissue, and anchors the skin to underlying structures.

Stratum Basale

The deepest layer of the epidermis, attached to the dermis, containing keratinocytes that rapidly divide to regenerate dead skin and produce keratin.

Keratinocytes

The most common type of cell in the epidermis, found in the stratum basale, responsible for producing keratin and regenerating dead skin.

Melanocytes

Cells found in the stratum basale that produce melanin, a pigment that determines skin color and protects against UV radiation.

Stratum Spinosum

A layer of the epidermis several cells thick, characterized by cells with a weblike system of intermediate filaments attached to desmosomes, sometimes called 'prickly cells'.

Stratum Granulosum

A layer of the epidermis where keratinization begins as cells move upwards from the basal layer, filling with keratin and flattening as organelles disintegrate.

Keratinization

The process that begins in the stratum granulosum where cells fill with keratin as they die, making them tougher and scalier for protection.

Stratum Lucidum

A clear layer of the epidermis, two or three cell layers thick, made of dead keratinocytes that have become flat and clear, where they begin to aggregate into tonofilaments.

Stratum Corneum

The outermost layer of the epidermis, twenty to thirty cell layers thick, composed of dead, anucleated cells filled with keratin, providing protection to the living cells inside.

Dermal Papillae

Projections from the papillary layer of the dermis that stick out into the epidermis above, containing tactile cells.

Dermal Ridges

Mounds on which dermal papillae sit in areas of high friction (e.g., hands), causing ridges in the epidermis and enhancing gripping ability.

Reticular Layer

The deeper layer of the dermis, made of dense fibrous connective tissue arranged irregularly.

Melanin

A pigment molecule produced by melanocytes that determines skin color and protects the skin from ultraviolet radiation.

Hair Follicles

Pockets that fold down from the surface of the epidermis into the dermis, producing hairs.

Hair Root

The part of the hair deep inside the follicle where keratinization is happening.

Hair Shaft

The part of the hair closer to the surface of the skin and extending outside the body, where keratinization is complete.

Hair Bulb

The expanded deep end of a hair follicle, containing a bundle of nerve endings and a hair papilla.

Hair Papilla

A bit of dermal tissue that protrudes into the hair bulb, supplying signals and nutrients to the hair for growth.

Hair Matrix

The actively dividing cells found in the hair follicle that push existing cells upwards, causing the hair to grow.

Arrector Pili

A small bundle of muscle cells attached to each hair follicle that can contract and pull the follicle, causing goose bumps.

Vellus Hair

Pale and fine body hair.

Terminal Hair

Darker and more coarse hair, such as hair of the eyebrows and scalp.

Nail Matrix

The area from which the nail grows, pushing the nail outwards across the nail bed as cells divide.

Nail Folds

Skin folds overlapping the borders of the nail on the lateral and proximal borders.

Eponychium

The skin fold that extends onto the nail from the proximal border.

Hyponychium

The area at the edge of the finger where dirt tends to collect.

Sudoriferous Glands

Also known as sweat glands, found almost everywhere on the surface of the skin, totaling around three million.

Eccrine Sweat Glands

The most common type of sweat gland, consisting of a coiled tube that secretes sweat (mostly water with some salts and metabolic wastes) through a pore.

Apocrine Sweat Glands

Sweat glands found only in certain areas that secrete fat and protein components along with the normal mixture, which is the cause of body odor. Ceruminous glands and mammary glands are types of apocrine glands.

Sebaceous Glands

Also known as oil glands, branched alveolar glands that secrete sebum, which softens and lubricates hair and skin, slowing water loss and killing certain bacteria.

Sebum

Oily lipids secreted by sebaceous glands that soften and lubricate hair and skin, slowing water loss and killing certain bacteria.