Chapter 22 - Integumentary System and Pathologies Flashcards
dermatology
study of the integumentary system
two primary regions of the skin
epidermis and dermis
functions?
protection, immunity, absorption, sensation, temperature regulation, excretion, vitamin D synthesis
what produces melanin?
melanocytes
specialized cells that stimulate immune responses when skin is broken by surgery or injury
dendritic (Langerhan) cells
epidermis
thin outer region of skin and composed of epithelial tissue
avascular
nutrients are provided by tissue fluids from underlying dermis
epidermis is derived from where
ectoderm
deepest epidermal layer where keratinocytes are produced
stratum basale
keratinocytes consist of __% in the epidermis
90
stratum basale is also known as
stratume germinativum or growth layer
melanin
produces dark pigment
1/4 cells are in stratum germinativum
melanocytes
melanin production is stimulated by sunlight which results in?
creating a semi protective shield against UV radiation
stratum spinosum (spiny layer)
slender projections connecting to the layer above
stratum granulosum (granular layer)
keratinization of skin cells begins
keratin
substance secreted by the vesicles within the keratinocytes
keratin + skin oils = ?
epidermal water barrier
epidermal water barrier
waterproofing the skin by reducing water loss that would lead to dehydration
stratum lucidum
translucent band that presents in thick skin of the palms and soles
stratum corneum (horny layer)
most superficial epidermal layer and desquamation occurs
how long do keratinocytes produce
21-27 days
epidermal-dermal junction
between the epidermis and the dermis
dermis (“true skin”)
thick, deeper region
dermis is derived from?
mesoderm
connective tissue consists mainly of
collagen and elastin
elastin
provides tissue to stay the same shape after being stretched
collagen
~70% of dermis and offer structural support to nerve receptors, blood vessels, hair follicles, muscles, and glands
scar
a dense collection of new connected tissue that is formed when the dermis is injured and the fibroblasts in the dermis quickly reproduce
stretch mark
resulted from the elastic fibers weakening and tearing from being overstretched in the dermis
subcutaneous layer
deep to the dermis
subcutaneous layer also known as?
hypodermis or superficial fascia
deep fascia
when this layer is extended inward and surrounds deeper structures
subcutaneous layers consist of (4)
loose connective tissue
adipose tissue
nerve receptors
blood vessels
skin color is determined by (5)
genetics
physiology
emotions
disease processes
diet
albinism
genetic condition in which individuals cannot produce melanin
vitiligo
partial or total loss of pigmentation occurring in patches
hyperpigmentation
from pregnancy hormones
linea nigra
a pregnancy line that is produced by pregnancy hormones stimulating melanin production
carotene
yellow pigment that gives skin the golden color
bilirubin
a pigment that is unable to excrete by individuals with liver diseases
jaundice
a medical condition caused by a substance that is deposited in skin and mucous membranes
hyperemia
reddening that is caused by vasodilation and increased blood flow
cyanosis
blue or purple-tinted skin
pallor
pale skin
ischemia
decreased blood flow from vasoconstriction or other causes
hair
keratinized filaments arising from pouchlike hair follicles in dermis
functions of the hair
protects skin and body orifices
arrector pili
muscles attached to hair follicles
nails
compact keratinized cells forming thin hard plates on distal surfaces at fingers at toes
body (of the nail)
largest and most visible part
root (of the nail)
nail production
nailbed
skin beneath the nail
lateral nail folds
sides of the nail
cuticle
tough ridge growing over the nail base
lunula
crescent shaped white area at the nail base
free edge
distal end and trimmed as nail growth
three major skin glands
sebaceous
sudoriferous
ceruminous
sebaceous (oil) glands
connected to a hair follicle and produces sebum
sudoriferous (sweat) glands
produce sweat or perspiration
functions of sudoriferous glands
regulate body temperature and eliminate wastes
two types of sudoriferous glands
eccrine glands
apocrine glands
eccrine glands
most numerous
secrete watery perspiration
assist with temperature regulation through evaporative cooling
apocrine glands
open into hair follicles and secrete a strong-smelling perspiration
ceruminous glands
produce cerumen, or earwax
thermoregulation
maintenance of normal body temperature by balancing heat production and heat loss
hypothermia
excess decreases in temperature
hyperthermia
excess increases in temperature
what area in the brain does the stimuli of the skin receptor travels to?
postcentral gyrus
free nerve endings
no covering
most common and widely distributed
3 types of free nerve endings
Merkel disk
Nociceptors
Hair root plexus
Merkel disk
detects light pressure light touch
nociceptor
detects noxious stimuli and protects the dermis layer
hair root plexus (hair follicle receptor)
looks like a web that responds to mechanical stimuli
encapsulated nerve endings
covered by capsules and stimuli mechanically changes their shape
Meissner (tactile) corpuscles
detects light pressure or light touch, textural sensations, and low frequency vibration
krause (bulboid) corpuscles
found in mucous membranes and detect deeper pressure, cold, or reduced temperatures
Ruffini (bulbous) corpuscles
respond to heavy pressure, continuous or persistent touch, skin touching, skin stretching, and warmth
pacini (lamellar) corpuscles
(aka Pacinian corpuscles)
respond to deep pressure, high-frequency vibrations, and stretch
acne
an inflammatory infection of the hair follicles and their associated sebaceous glands
athlete’s foot
fungal infection of the foot
dermatophytes
several species of fungi that causes athletes foot
boils (furuncles)
deeply infected hair follicles that spread to surrounding areas
carbuncle
collection of boils that coalesce to form a larger mass draining through several openings
bruises
marks on skin caused by blood leaking from damaged vessels and collecting in interstitial spaces
is massage contraindicated for bruises?
yes
burn
injury causing damage to the epidermis, dermis, subcutaneous layer or organs underneath
4 types of burns
1st degree burn
2nd degree burn
3rd degree burn
4th degree burn
1st degree burn is also called?
superficial partial-thickness burn
1st degree burn
damages only the epidermis
2nd degree burn aka?
deep partial-thickness burn
2nd degree burn
deeper and involves both epidermis and upper layers of dermis
hair follicles and sweat glands are spared and remain function
3rd degree burn aka?
full-thickness burn
3rd degree burn
destroys the epidermis, dermis, hair follicles, and associated glands
4th degree burn
full thickness burn that extends into the bone and muscle
burns caused by
heat sources
cold
radiation
chemical agents
electricity
friction