anaphy lesson 5

Integumentary System

Consists of the skin and accessory structures such as hair, glands, and nails

Integument

Means covering

Epidermis

First layer of the skin

Keratinization

Process in which epidermal cells change shape and chemical composition as they move outward

Keratinocytes

Most abundant cells in the epidermis that produce keratin

Melanocytes

Cells that produce melanin

Callus or Corn

Forms when skin is subjected to pressure or friction

Stratum Basale

Deepest epidermal layer

Stratum Corneum

Most superficial epidermal layer

Dermis

Second layer of the skin composed of dense collagenous connective tissue

Subcutaneous Layer

Layer that attaches the skin to underlying bones

Hypodermis

Another name for the subcutaneous layer

Melanin

Pigment responsible for skin, hair, and eye color

Melanosomes

Vesicles derived from the Golgi apparatus where melanin is produced

Genetic Factors

Factor affecting melanin production

Albinism

Recessive genetic trait causing deficiency or absence of melanin

Cyanosis

Bluish skin color caused by decreased blood oxygen

Carotene

Yellow pigment in plants and source of Vitamin A

Birthmarks

Congenital disorder of capillaries in the dermis

Hair

Columns of dead, keratinized epithelial cells produced in the hair bulb

Hair Follicle

Structure where each hair arises

Shaft

Part of the hair above the skin

Root

Part of the hair below the skin

Hair Bulb

Site of hair cell formation

Cortex

Hard keratin portion of the hair

Medulla

Soft central core of the hair

Cuticle of Hair

Single layer of overlapping cells that holds hair in the follicle

Sebaceous Glands

Simple branched acinar glands connected to hair follicles

Sebum

Oily white lipid-rich substance that lubricates hair and skin

Eccrine Sweat Glands

Sweat glands that release sweat by merocrine secretion

Apocrine Sweat Glands

Sweat glands found mostly in armpits and genitalia

Ceruminous Glands

Glands that produce earwax

Cerumen

Earwax produced by ceruminous glands

Mammary Glands

Glands that produce milk

Nails

Dead stratum corneum cells containing hard keratin

Nail Body

Visible part of the nail

Nail Root

Part of the nail covered by skin

Cuticle of Nail

Eponychium extending onto the nail body

Nail Matrix

Produces the nail

Nail Bed

Contributes to nail formation

Lunula

White crescent-shaped area visible through the nail body