chapter 4 integumentary system

what is the integumentary system composed of?

skin, nails, hair, oil, and mammary glands

function of the integumentary

physical protection, regulation of body temperature, excretion (secretion), nutrition (synthesis), sensation, immune defense

what are the 3 main layers of the integumentary

epidermis (outer), dermis (middle), hypodermic (doesn’t really count as a layer but it is the fat layer)

what is the epidermis and what does it do?

is the stratified squamous epithelium, and it protects the body from germs, water loss, and injuries

what protein makes skin tough and waterproof?

keratin

what is the dermis and what does it contain?

is the underlying loose connective tissue, it contains blood vessels, nerves, sweat glands, oil glands, and hair roots

what does the hypodermic (subcutaneous layer) do?

stores fat, keeps body warm, cushions organs

what are keratinocytes?

skin cells that make keratin, a protein that makes skin strong and waterproof

what are melanocytes?

cells that make melanin, the pigment (color) that protects skin from the sun

what are Merkel cells?

cells in the skin that help us sense touch and pressure

what are langerhans cells?

immune cells in the skin that fight off germs and protect from infection

what are the layers (superficial to most deepest (top to bottom)?

stratum corneum

stratum lucidum

stratum granulosun

stratum spinosum

stratum basale

what is stratum corneum

top layer, made of dead, flat keratin-filled cells

what is stratum lucidum

only in thick skin (palms and soles)

what is stratum granulosum

cells start to die and fill with keratin

what is stratum spinosum

gives strength and flexibility

what is stratum basale

the base layer, where new skin cells are made

what are the 2 dermis layer

papillary and reticular layer

what is the papillary layer?

the top layer of the dermis, it has thin connective tissue (mainly areolar), blood vessels, and makes fingerprints (20% of the dermis)

what does the papillary layer do?

supplies nutrients to skin, supports the epidermis, and has touch receptors

what is the reticular layer?

the deeper layer of the dermis; it is thicker and made of dense (irregular) connective tissue (80% layer of the dermis)

what does the reticular layer do?

provides, strength, elasticity, and contains sweat glands, oil glands, and hair follicles

aprocine glands in the integumentary

sweat glands (pubic, axillary and the male facial hair)

eccrine in integumentary glands

sweat glands (found in the palms, soles of feet and forehead) doesn’t have a smell

sebaceous glands

oil

ceruminous glands

glands of the ear canal that produce cerumen (earwax)

four primary tissue types in the hair

epithelium, connective, smooth and nervous

What are the accessory structures of the integumentary

Hair, hair follicles, nails, sweat glands, oil (sebaceous) glands, and sensory receptors.

what is most of our body made up of?

thin skin

where is thick skin found?

sole of the foot and palm of the hands

why do you have stratified versus non-stratified

stratification is protected

what are bones responsible for

hemopoiesis or hematopoiesis (blood cell production)