Physiology of the dermis and hypodermis

hypodermis

subcutaneous layer

dermis

deep layer, connective tissue, split into 2 layers

2 layers of dermis

reticular, papillary

reticular layer

deeper, thick, 80% of dermis

papillary layer

superficial, thin, 20% of dermis

dermal papillae

skin nipple, bind epidermis and dermis, create fingerprints papillary layer

Meissner's corpuscles

sense light touch
papillary layer

capillary loops

oxygen and nutrients dropped off in dermis, where co2 and waste removed from dermis
papillary layer

free nerve endings

sense pain, heat, cold, itching, and tickling
papillary layer

hair follicle

tunnel where hair grows
reticular layer

arrector pili muscle

contracts to raise hair on end
reticular layer

Sebaceous gland

oil glands, oil called sebum
reticular layer

pacinion corpuscles

sense heavy touch
reticular layer

adipose tissue

adheres skin to underlying muscle, insulates heat, absorbs shock
hypodermis layer

sensory nerve

sends messages to merkiel cells, meissners corpuscle, free-nerve endings and pacinians corpuscle to the brain
hypodermis layer

motor nerve

Sends messages from brain to the arrector pili muscles, sebaceous glands, and sudoriferous glands
hypodermis layer

blood vessels

delivers blood to and from skin.
artery: drops off blood with oxygen and nutrients.
veins: takes away blood with co2 and waste.
hypodermis layer

functions of the skin

protection, sensing, vitamin D synthesis, Excretion, Body temperature regulation

color for two form of melanin

eumalanin, brown
pheomelanin, red/yellow

color for carotene

orange/yellow

hemoglobin color

red