4b... LETS GOOO Flashcards
What does the integumentary system consist of?
skin (cutaneous membrane), skin appendages
what are the skin appendages?
sweat/oil glands, hair and nails
what are the functions of the integumentary system
insulates/cushions deeper body organs, protects the entire body, regulates heat loss as controlled by the nervous system, acts as a mini-excretory system, synthesizes vitamin D, secretion’s create a protective acid mantle.
what does the integumentary system protect the body from?
mechanical damage, chemical damage, thermal damage, ultraviolet/radiation, microbes, water loss
sweat aids in the loss of what?
urea, salts, water
What are the two kinds of tissue that the skin is composed of?
epidermis, dermis
what does the subcutaneous tissue do?
anchors the skin to underlying organs, serves as a shock absorber and insulates deeper tissues.
what is subcutaneous tissue composed mainly of?
adipose tissue
What is the epidermis composed of?
stratified squamous epithelium, 5 layers of strata
what is the deepest layer of epidermis
stratum basale
where does the stratum basale lie?
next to the dermis
epidermis characteristics
most cells are called keratinocytes which produce a fibrous protein called keratin, avascular
epidermis characteristics
most cells are called keratinocytes which produce a fibrous protein called keratin, avascular
what connects keratinocytes together?
desmosomes
what makes the epidermis tough?
keratinization
order of strata layers from deepest to most superficial
stratum basale, spinosum, granulosum, lucidum (thick, hairless skin only), corneum
how are stratum basale anchored to each other?
wavy borderline with dermis
what do stratum basale cells do?
undergo mitosis, daughter cells are pushed upward to become more superficial layers
what do stratum spinosum cells do?
become increasingly flatter and more keratinized.
how are stratum lucidum formed?
from dead cells of the deeper strata
where does stratum lucidum occur?
only in thick hairless skin of palms of hands and soles of feet
what is the stratum corneum?
outermost layer of epidermis
what are stratum corneum cells like?
shingle like dead cells are filled with keratin (protective protein prevents water loss from skin).
what is melanin?
a pigment produced by melanocytes
where are melanocytes found mostly?
the stratum basale
what colors are melanin
yellow, brown, black
epidermal dendritic cells
alert and activate cells to a threat (bacterial/viral invasion)
what are merkel cells associated with?
sensory nerve endings
what do merkel cells serve as?
touch receptors called merkel disks
what are the characteristics of dermis?
connective tissue, underlies epidermis, has two regions
what are the two regions of dermis?
papillary, reticular
what does the papillary layer contain?
projections called dermal papillae, aereolar connective tissue
what does the dermis do to the epidermis
indents it
what does the dermal papillae contain
many contain capillary loops, and others house pain and touch receptors
what does the papillae do?
on palms and soles, it increases friction and gripping ability, fingers are identifying films of sweat.
what does the reticular layer consist of?
dense irregular connective tissue, blood vessels, sweat/oil glands, deep pressure receptors (lamellar corpuscles)
other dermal features
cutaneous sensory receptors, phagocytes, collagen and elastic fibers, blood vessels, nerve supply
