Structure and Function of the Integumentary System

Vocabulary

apocrine gland

gland in the dermis that produces sweat containing lipids and proteins

arrector pili muscle

muscle attached to hair follicles that supports each hair that exits the dermis. In cold conditions it contracts to release thermal energy.

ceruminous gland

modified apocrine gland in the external ear whose secretions mix with sebum to form earwax

dermis

thick, inner layer of skin just below the epidermis that makes up about 90 percent of the skin's thickness

eccrine gland

gland in the dermis that secretes sweat made mostly of water and plays an important role in thermoregulation

epidermis

outermost layer of skin, comprised of several sublayers

hypodermis

deepest layer of the skin, made up mostly of areolar connective tissue and adipose tissue

keratin

structural protein that lends durability and water impermeability to skin, hair, and nails

keratinocyte

keratin-producing cell found in the skin

Langerhans cell

immune cell that engulfs foreign particles and pathogens when the skin is damaged

mammary gland

specialized sweat gland that secretes milk

melanocyte

cell in the deepest layer of the epidermis that produces melanin

Merkel cell

type of receptor cell in the skin triggered by light touch

papillary layer

outer layer of the dermis; contains a network of small blood and lymph vessels that provide nutrients to the epidermis

reticular layer

deep layer of the dermis that contains hair follicles and sweat and oil glands

sebaceous gland

gland that is joined to a hair follicle that produces oil to keep the skin supple and prevent the growth of microorganisms

stratum basale

deepest layer of the epidermis; a single-celled layer of basal cells

stratum corneum

outermost layer of skin; serves as the primary barrier against microbes and keeps the deeper layers from dehydrating

stratum granulosum

layer of the skin where keratinocytes produce keratin and then flatten and lose their nuclei

stratum lucidum

layer of the skin found only in certain areas of the body; provides extra padding and durability

stratum spinosum

layer of the epidermis that has a spiny appearance due to the keratinocytes that dominate it. It lends durability to skin.

sudoriferous gland

gland that helps regulate body temperature through evaporative cooling