anatomy test integumentary system review

integument

Another name for skin

hair, oil glands, sweat glands, nails

apendages of the skin

2.2 square meters and 15%

skin measures ______ and accounts for ___ of your body weight

2 layers (epidermis and dermis)

how many layers is the skin

epidermis

superfiscal layer, made of epitheal cells, outermost protective layer of body, and avascular

dermis

deeper layer of skin, makes up most of skin, made of connective tissue, and vascular

subcutaneous tissue

not part of skin, deep to the skin, know as hypodermis, and made of adipose tissue

keratin

a protein that helps the epidermis protect from abrasions/penetration and remain waterproof

keratinocytes

90% of epidermal cells, produce keratin, made in stratum basale (but get pushed upward by new cells beneath them; approach surface=flatten and die), shed millions daily, frictions

25-45

new epidermis every ______ days

langerhans cells (dendritic cells)

formed in bone marrow (migrate to stratum spinosum of epidermis), ingesting foreign substances and activate our immune system.

melanocytes

spider shaped, produce melanin, all have similar # of them, found in stratum basale, malanin covers kerationcytes (blocks UV radiation from the sun)

melanin

a pigment that determines hair, skin, and eye color

merkel cells (tactile epithelial cells)

present at the junction between the epidermis and dermis, sense light touch

stratum corneum- keratinocytes are dead

superfiscal epidermal layer (outer layer of skin), 20-30 layers of squamous acumulas keratinocytes, cells are dead and shed, 31% of epidermis thickness, highly keratinized (protects against abrasions, penetration, and waterproofs skin)

stratum lucidum- keratinocytes are dead

clear layer, cells lose nuclei and die, only found in thick skin

stratum granulosum- keratinocytes are living but begin to die

keratinocytes produce granuels called keratohyalin granules and release lamellar bodies

keratohyalin granules

herlp form keratin in upper strata

lamellar bodies

release lamellar that waterproof our skin

stratum spinosum- keratinocytes are living

kerationocytes are connected by desmosomes- make them appear spiny

stratum basale- keratinocytes are living

deepest epidermal layer, right above and attached to dermis, consists of a single row of stem cells that rapidly undergo mitosis, creating new keratinocytes, and pushing the higher layers higher

2 layers; reticular and papillary layer

how many layers is the dermis and what are the names of the layers

reticular layer

deeper, thick layer of dermis; bottom 4/5 of dermis

papillary layer

superfiscal, thin layer of dermis; top 1/5 of dermis

hair follicle, arrector pili muscle, sebaceous gland, sudoriferous gland, pacinian corpuscle

aspects of the reticular layer of dermis

dermal papillae, meissner’s corpuscle, capillary loops, free nerve endings

aspects of the papillary layer of dermis

dermal papillae

“skin nipples,“ bumps that bind the epidermis and dermis, create finger prints

meissner’s corpuscle

sense light touch

capillary loops

where oxygen and nutrients are dropped off in the dermis (shared with the epidermis), here CO2 and waste are removed from the dermis

free nerve endings

sense pain, heat, cold, itching, and tickling

hair follicle

tunnel where the hair grows from

arrector pili muscle

contracts to raise hair on end

sebaceoous glands

oil glands, oil is called sebum

sudoriferous gland

sweat glands

pacinian corpuscle

sense heavy touch (pressure and vibrations )

hypodermis

superfiscal layer; consists of adipose tissue, sensory nerve, motor nerve, and blood vessels

adipose tissue

adheres to skin underlying muscle (anchored loosely enough to allow skin to slide), insulates heat, absorbs shock

sensory nerve

sends messages from the kerkel cells, meissner’s corpuscles, free nerve endings and pacinian corpuscles to the brain

motor nerves

sends messages from the brain to the arrector pili muscles, sebaceous galnds, and sudoriferous glands

blood vessels

delivers blood to and from the skin; artery: drops off blood with oxygen and nutrients; vein: takes away blood with CO2and waste

Vitamin D

when exposed to UV rays our skin produces…

absorb calcium

vitamin D helps our digestive track….

rickets

when deficient in vitamin D causes weak bones

excretion of the skin

sweat contains waste: salt, water, traces of urea

pili

other name for hair

dead, keratinized cells

hair is made of…

palms, soles, lips, nipples, and part of the genitals

hair is not located on:

shaft

part of hair above the skins surface, determines texture

root

the part of the hair embedded into the skin

follicle

tunnel in the epidermis/dermis that the hair grows from

sense insects on the skin

body hairs function

filters particles in the air that we inhale

function of nose hair

protects against heat loss and sunlight

function of scalp hair

shield the eyes from dust and dirt

function of eyelashes

texture is determines by…

the shaft

round shaft

straight hair

oval shaft

wavy hair

flat shaft

curly hair

terminal hair

eyebrows, eyelashes, and scalp; darker and thicker; appear in the axillary (armpit) and pubic region (and face/body of males) during puberty

vellus hair

peach fuzz found on the face, arms, legs, and stomatch; “wool“

nail matrix

the thickened proximal portion of the nail bed; responsible for nail growth

eponychium

also known as the cuticle; layer of clear skin along the bottom of a fingernail or toenail

nail plate

also known as the nail body; the actual fingernail; made of keratin

free edge

the nail tip; distal, free part of the nail plate

nail fold

skin folds over the proximal and lateral borders of the nail

nail root

proximal part pof the nail plate embedded in the skin

nail bed

pinkish colored soft tissue underneath the nail plate

lunula

visible portion of the nail matrix; white crescent; “little moon“

sebaceous glands

oil glands, secrete sebum, all over body except palms and soles, usually grow on hair follicles, larger on face, chest, and neck…

soften and lubricate hair and skin, prevent water loss, bactericidal action: kill bacteria

functions of sebum

sudoriferous glands

sweat glands, distributed over skins sirface except nipples and parts of genitals, up to 3 mill per person, cont5raction of gland forces sweat out to skin’s surface; two types eccrine and apocrine

eccrine glands

more numerous, abundant on palms, soles, and forehead, sweat they secrete is 90% water, and some salt&urea, thsi sweat prevents bodt from overheating

apocrine

2,000 of them, only in axillary and genital region, larger, sweat includes normal factors + fats, milky and viscous, ordorless until bacteria feeds on the skin causing body odor, begin to function at puberty,

ceruminous glands: produce earwax; mammary glands: produce milk

two types of modified apocrine sweat glands: