chapter 5 a&p lab

skin

provides protection from pathogens, temp regulation, sensory input

3 skin layers

dermis, epidermis, hypoermis

epidermis

outermost layer

dermis

contains blood vessels, glands, hair follicles, sensory receptors

hypodermis

adipose and loose areolar tissue, insulates and anchors dermis

stratum corneum

outermost layer, sloughed off constantly making household dust, thickest layer

stratum lucidum

only on palms and soles

stratum granulosum

cells undergo the final conversion of keratin production and die

stratum spinosum

cells held together by desmosomes and melanin is taken into keratinocytes

stratum basale

single layer that continually divides, mostly keratinocytes which help waterproof skin and melanocytes that determine skin color and tanning

papillary layer

below the epidermis, composed of areolar connective tissue, blood vessels, and fine touch receptors

reticular layer

contains collagen and elastic fibers, glands, hair follicles, and deep pressure receptors

dermal papillae

cone-shaped projections which increase adhesion between the epidermis and dermis

sebaceous gland

surround hairs, produce oil(sebum) to prevent dehydration and make hair more bendy(pliability)

sudoriferous gland

secret sweat for evaporative colling(heat of body leaves with sweat evaporation)

hair follicules

hollow tubes that contain hair shaft

arrector pili

muscle that produces goose bumps, originally made to puff up hairs to make animals look more intimidating and to insulate heat

pacinian corpuscle

mechanoreceptors sensitive to deep pressure and vibration

Meissner’s corpuscles

fine touch receptors

sebum

nutrient-rich lipid mixture, utilized by bacteria that live on our skin, if trapped can form pimple or cyst