Chapter 6 Integumentary System Flashcards
The cutaneous membrane in the integumentary system makes up what?
integument skin
describe epidermis, dermis, and hypodermis
epidermis- consists of keratinized, stratified squamous epithelium with layers
dermis- composed of CT proper and contains two layers
hypodermis- subcutaneous layer that is not part of integument
what are the layers of the Epidermis?
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
what three cell types are in the stratum basale layer of the epidermis?
keratinocytes, melanocytes, and tactile cells
describe keratinocytes
large stem cells in basale layer that synthesizes keratin
describe melanocytes
found in stratum basale and produces, stores pigment and transfers melanosomes
describe tactile cells
merkel cells are sensitive to touch and when compressed, release chemicals, stimulate sensory nerve endings
describe stratum spinosum
several layers of polygonal keratinocytes when new cells pushed into this layer by stratum basale
what are nondividing keratinocytes in the stratum spinosum attached by?
desmosomes
what are epidermal dendritic cells
Langerhans cells found in stratum spinosum and granulosum that initiates immune response
describe stratum granulosum
3 to 5 layers of keratinocytes where they begin keratinization
what is keratinization?
when keratinocytes fill with keratin and the nucleus disintegrate, dead cells
Describe Stratum lucidum
translucent layer found only on thick skin on palms and soles and cells filled with eleidin
describe stratum corneum
composed of 20 to 30 layers of dead, interlocking, anucleate, keratinized cells that protects skin from abrasion
describe hemoglobin
oxygen-binding protein in red blood cells
describe melanin
dark pigment produced in melanocytes, transferred to keratinocytes. contains Eumelanin (brown and black shades) and Pheomelanin (tan, yellow, red)
Describe Carotene
yellow-orange pigment from vegetables
describe nevus and freckles
nevus is an overgrowth of melanocytes
freckles is increased melanocyte activity
describe hemangiomas and friction ridges
hemangiomas is a skin discoloration due to benign blood vessel tumor
friction ridges are large folds and valleys of dermis and epidermis (fingerprints)
what the three types of radiation does the sun generate?
UVA, UVB, UVC
which two radiations need SPF (sun protection factor)
UVA and UVB
describe Dermis
composed of CT proper and contains papillary and reticular layers
describe the papillary layer of the dermis
areolar connective tissue that contains dermal papillae which interlocks with epidermal ridges to increase area of contact between layers
describe the reticular layer of the dermis
deeper, major portion of dermis that is dense irregular connective tissue
orientation of bundles of collagen and elastic fibers are indicated by what?
lines of cleavage
what is another word for stretch marks?
striae
what is the function of the subcutaneous layer?
protection, energy storage, and insulation
what are the functions of the integument?
protection from external environments
prevention of water loss/gain
vitamin D synthesis- formation of vitamin D3, a precursor to calcitriol
secretion- sweat
absorption
immune function
temperature regulation-dermal blood vessels capable of vasoconstriction to conserve heat or vasodilation to release heat
sensory reception
what is the structure of nails?
distal whitish free edge, pinkish nail body, nail root, and nail bed, nail matrix (growing part), lunula (whitish semilunar area), eponychium (cuticle), hyponychium (thickened skin just below free nail edge)
what is Onychomycosis and yellow nail syndrome?
onychomycosis is a fungal infection
yellow nail syndrome occurs when growth and thickening slows
what is keratinized cells forming slender filament?
hair
what are the three types of hair and describe them
lanugo- fine, unpigmented, downy hair
vellus- fine hair
terminal hair- coarser, pigmented, longer
What are the three zones along length of hair?
hair bulb, root, and shaft
what is hair papilla composed of?
Connective Tissue
describe hair matrix
structure at base of hair bulb when epithelial cells divide
describe Medulla
remnant of matrix this is flexible, soft keratin
describe cortex
flattened cells closer to outer hair surface
describe cuticle
single cell layer around cortex
describe Hair follicle
has outer CT root sheath originating in dermis and inner epithelial tissue root sheath originating from epidermis
describe arrector pili
thin ribbons of smooth muscle that elevate hair with contraction
what is the function of hair
protection, heat retention, sensory reception, visual identification, hair color, hair growth and replacement
what are the three phases of the hair growth cycle?
anagen- active phase
catagen- brief regression
telogen- resting phase
What are a few hair medical conditions?
alopecia areata, diffuse hair loss, male pattern baldness, and hirsutism
What are the two exocrine glands of the skin?
sweat glands and sebaceous glands
describe the two types of sweat glands
merocrine- discharge into skin surface and produces secretion by exocytosis and secretes sweat; major role in thermoregulation
apocrine- discharge into hair follicles and produce odor when acted on by bacteria, starts producing secretions during puberty
Describe sebaceous glands
holocrine glands that produce sebum and activated during puberty
Describe Ceruminous glands
modified apocrine sweat glands located in external ear canal that secretes cerumen
what two ways are tissue repaired?
regeneration and fibrosis
describe fibrosis
gap filled with scar tissue which is collagen produced by fibroblasts
what are the stages of wound healing?
cut
blood clot form and white blood cells take action
blood vessels re-grow and granulation tissue forms
epithelium regenerates and CT fibrosis occurs
Describe psoriasis
skin disease when keratinocytes are attacked by T-lymphocytes which causes rapid overgrowth and patches of whitish, scaley skin form
Describe first degree and second degree burns
first degree burns- only epidermis, slight pain
second degree burns-epidermis and part of dermis with blisters and scarring
describe third degree burns
involve epidermis, dermis, and subcutaneous layer that may need a skin graft
At development week 7, ectoderm forms a layer of squamous epithelium that becomes what layer of the integument?
periderm and basal layer
at development week 21, formation of stratum corneum and friction ridges produces what?
vernix caseosa
at development week 11, dermis is derived from mesoderm and the mesoderm becomes what?
mesenchyme
what develops at week 32?
fingernails and toenails
what appears between 9 weeks and 12 weeks?
hair follicles and hair buds
what appears on week 20?
sweat and sebaceous glands appear on palms, soles
