Integumentary system

Skin is largest organ by area and volume
Sensory organs
Exocrine organs
    Release to the outside
Accessory organs

Primary function is protection
    Waterproof layer
        Keep water inside of us
General senses
    Touch = general sense
    These nerve endings are found in the integumentary system
Creates chemicals
Immunity
    Excretory and immune system
Secretion

Tissues
    Stratified squamous, areolar, smooth muscle, nervous tissue
    Skin is cutaneous membrane

Epidermis    \
              |------   the thick part
Dermis       /

Hypodermis/subcutaneous
    Insulation + protection

_______EPIDERMIS_______
Corneum - dead - protection
Lucidum - dead - clear, only palms and soles
Granulosum - last living layer
Spinosum - largest
Basale - nourished + growing - cell factories that push cells upward

Pacinian - pressure - deep
Meissner’s - light touch - superficial
Free endings - temperature - v. superficial



Nails
    Lunula

Hair
    Growth cycle
    Follicle, root, shaft
    Follicle shape = texture   round oval flat
    Color determined by different types of melanin than your skin

Glands
    Sebaceous - along hair - sebum
    Eccrine - small (secrete water + urea) - separate from hair follicles
        Look like knots
        Sweat pore
        Excrete urea to (toxins)
        Water cools you off
    Apocrine - large
        Apocrine and eccrine look the same except apocrine is larger
            Sudoriferous
            Apocrine only in axial and genital region
Water + urea, protein and fat
    Purpose of these secretions is unknown
        Pheromones (possibly)




TEST RUNDOWN   {

Layers
    Dermis
        2 layers
    Epidermis
        5 layers
    Membrane
        Cutaneous

Nerve endings
Sweat glands
Finger nails
Hair
What happens when a dermis grows
What happens when u get old
    Lose elastin
Why does hair look way it does
    Melanin
    size/shape of follicle (circle oval elongated)
Burns
What gives skin color
    Melanocytes # + size of melanin molecule
    Density of blood vessels/fat over blood vessels
    Carotene - makes skin yellow

Picture that is simpler than coloring
Matching of parts of skin
}


Deodorant
    Destroys bacteria
    Cleans up the fat

Antiperspirant
    clogs sweat glands
    bad, dont use this crap