The integumentary system Flashcards
The integument is made up of two parts:
-cutaneous membrane (skin)
-accessory structures
True or False:
The integument is the largest system of the body at 16% body weight.
TRUE
What two parts make up the cutaneous membrane?
-outer epidermis
-inner dermis
Accessory structures:
-originate in the dermis
-extend through the epidermis to skin surface
Circulatory system (connection to integumentary)
contain blood vessels within the dermis
Nervous system (connection to integumentary)
Responsible for sensory receptors for pain, touch, and temperature
Subcutaneous layer
also known as the hypodermis, is the deepest layer of skin, located below the dermis and closest to the muscles.
It’s made up of fat, connective tissue, blood vessels, and nerves.
What are 6 important functions of the skin
-protects
-excretes
-maintains body temp
-synthesizes
-stores lipids
-detects
Keratinocytes
-contain large amounts of keratin
-most abundant cells in the epidermis
Thick skin:
-covers the palms of the hands and soles of the feet
-has 5 layers of keratinocytes
Thin skin:
-covers most of the body
-has 4 layers of keratinocytes
What are the layers of strata from basal lamina to free surface?
-stratum basale
-stratum spinosum
-stratum granulosum
-stratum lucidum
-stratum corneum
The “Basale layer”
AKA germinative layer
-has many germinative (stem) cells or basal cells
-attached to basal lamina by hermidesmosomes
-forms a strong bond between epidermis and dermis
What are the two structures of the
basale
aka germinativum
-epidermal ridges
-dermal papillae
Epidermal ridges
fingerprints
Dermal papillae
strengthen attachment between epidermis and dermis
Merkel cells
-found within hairless skin and respond to touch
Melanocytes
scattered throughout stratum germinativum and contain melanin
Stratum spinosum AKA “spiny layer”
-produced by division of stratum germinosum
-8-10 layers or keratinocytes bound by desmosomes
Stratum granulosim:
stops dividing and starts producing keratin and keratohyalin
Keratin
tough, fibrous protein that makes up hair and nails
Cells of the stratum granulosum:
-produce protein fibers
-dehydrate and die
Stratum lucidum:
found only in thick skin
-flat, dense, and filled with keratin
Stratum corneum
-exposed surface of skin
-15-30 layers of keratinized cells
-water resistant
-shed and are replaced q2w
Keratinization
the formation of a layer of dead, protective cells filled with keratin
- on all exposed skin surfaces except eyes
Skin life cycle
15-30 days from germinosum to cornerum
Insensible perspiration
Interstitial fluid lost by evaporation through the stratum corneum
Sensible perspiration
water excreted by sweat glands
Dehydration results on skin
-comes from damage to stratum corneum
-from immersion in hypertonic solution ex: salt water
Hydration (regarding skin)
-Results from immersion in hypotonic solution ex: freshwater
-causes stretching and wrinkling of skin
Skin color depends on:
melanin and carotene
melanin production, not # of melanocytes
Melanin
-yellow, brown or black pigments
-produced by melanocytes
-stored in transport vesicles
Carotene
-orange-yellow pigment
-found in orange vegetables
Cyanosis
bluish skin tint caused by severe reduction in blood flow or oxygen