Anatomy exam ch 5

epidermis

epidermis

superficial, thinner portion of the skin that contains epithelial tissue

where epithelium is found

hair, nails, epidermis of skin

where connective tissue is found

dermis

where muscle is found

attached to hair follicles and in the substance of arteries and veins

functions of the integumentary system

regulation of body temperature, reservoir for blood, protection from the external environment, sensory perceptions, excretes and absorbs, synthesis of vitamin D

cells of the epidermis

keratinized stratified squamous epithelium

90% of epidermal cells

produce tough, fibrous protein, keratin

8% of epidermal cells

produce melanin

Thin skin

covers all body regions except the palms, palmar surfaces of digits, and soles

thick skin

palms, palmar surfaces of digits, and soles

most superficial layer of epidermis

stratum corneum

layer under stratum corneum

stratum lucidum

layer under stratum lucidum

stratum granulosum

layer under stratum granulosum

stratum spinosum

layer under stratum spinosum

stratum basale

papillary region

lies just deep to the epidermis and consists of areolar connective tissue

reticular region

consists of dense irregular connective tissue containing collagen and elastic fibers, adipose cells, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands

Hair function

protection, reduction of heat loss, sensing light touch

hair composition

hair structure

shaft which mostly projects above the surface of the skin and root which penetrates into the dermis

shaft

projects mostly above the surface of the skin

root

part of hair that penetrates into the dermis

lanugo

fine, nonpigmented, downy hairs that cover the body of the fetus

vellus hairs

short, fine, pale hairs barely visible to the naked eye

terminal hairs

long, coarse, heavily pigmented hairs

sebaceous glands

secrete an oily substance called sebum, prevents dehydration of hair and skin, inhibits growth of certain bacteria

sudoriferous glands

eccrine sweat glands, help to cool the body by evaporation, eliminate small amounts of wastes

ceruminous glands

involved in producing a waxy secretion called cerumen

nail root

portion of the nail that is not visible

eponychium (cuticle)

the stratum corneum of the epidermis

lanula

thick, white part of the nail

nail bed

skin below the nail plate

nail body

visible portion of the nail

free edge

extends past the finger or toe

hyponychium

secures nail to the fingertip

nail matrix

epithelium proximal to the nail root

4.5% burn

anterior head and neck

9% burn

anterior shoulders, arms, forearms, and hands

9% burn

anterior and posterior head and neck

18% burn

anterior and posterior shoulders, arms, forearms, and hands

36% burn

anterior and posterior trunk

1% burn

perineum

36% burn

anterior and posterior thighs, legs, and feet

18% burn

anterior thighs, legs, and feet

hemoglobin

a red pigment in red blood cells, helps to transport oxygen

carotene

a yellow-orange pigment stored in the stratum corneum and adipose tissue

most at risk for developing rickets

children born to mothers with dark skin, living far from the equator