Integumentary System Flashcards
skin = ??? membrane
cutaneous
2 regions of the skin
epidermis & dermis
outer layer of the skin; stratified squamous epithelium
epidermis
to prevent water loss, epidermis is ?
cornified/keratinized
avascular or vascular? epidermis.
avascular
most cells in epidermis
keratinocytes
avascular or vascular? dermis.
vascular
dense connective tissue
dermis
subcutaneous tissue deep to dermis
hypodermis
not technically part of skin
hypodermis
hypodermis fx
anchors skin to underlying organs
hypodermis is composed mostly of what tissue
adipose tissue
layers of epidermis (start from deepest)
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
stratum basale
stratum germinativum
deepest layer of epidermis
stratum basale
stratum basale lies next to where
dermis
wavy borderline with the dermis anchors the two together
stratum basale
cells undergoing mitosis where daughter cells are pushed upward to become the more superficial layers
stratum basale
stratum spinosum
prickly layer
several cell layers thick that contain weblike system of intermediate filaments
stratum spinosum
stratum granulosum
granular layer
4-6 layers thick that accumulates 2 types of granules
stratum granulosum
2 types of granules accumulated in stratum granulosum
keratohyaline granules & lamellar granules
granule: help to form keratin in the upper layer
keratohyaline granules
granule: contain water resistant glycolipid (protein) for slowing water loss across epidermis
lamellar granules
stratum lucidum
clear layer
formed from dead cells of the deeper strata
stratum lucidum
occurs only in thick, hairless skin of the palms of hand and soles of feet
stratum lucidum
stratum corneum
horny layer
outermost layer of the epidermis
stratum corneum
shingle-like dead cells are filled with keratin
stratum corneum
protective protein that prevents water loss from skin
keratin
cells in the epidermis (4)
keratinocytes
melanocytes
dendritic (Langerhans) cells
tactile (Merkel) cells
cells that produce keratin
keratinocytes
where do keratinocytes arise in
in the deepest part of the epidermis (stratum basale)
fibrous protein that helps give the epidermis its protective properties
keratin
spider-shaped epithelial cells
melanocytes
cells that synthesize melanin pigment
melanocytes
where are melanocytes found
deepest part of the epidermis
cells that ingest foreign substances and are the key activators of our immune system
dendritic (Langerhans) cells
dendritic (Langerhans) cells arise from where and migrate to where
bone marrow and migrate to the epidermis
cells that functions as sensory receptor for touch
tactile (Merkel) cells
tactile (Merkel) cells are present at
the epidermal-dermal junction
2 layers of dermis
papillary and reticular layer
upper dermal region
papillary layer
tissue of papillary layer
areolar connective tissues
collagen and elastic fibers form a loosely woven mat
papillary layer
projections in papillary layer
dermal papillae
some contain capillary loops and others house pain receptors and touch receptors
dermal papillae
pain and touch receptors
tactile/Meissner’s Corpuscles
80% of the thickness of the dermis
reticular layer
tissue of reticular layer
dense fibrous connective tissue
important to surgeon
cleavage (tension lines)
dermal folds that occur at or near joints
flexure lines
normal skin color determinants
melanin
carotene
hemoglobin
polymer made of tyrosine amino acids
melanin
yellow, brown, or black pigments
melanin
orange-yellow pigment from some vegetables
carotene
pigment: accumulates in the stratum corneum and in fatty tissue of the hypodermis
carotene
red coloring from blood cells in dermal capillaries
hemoglobin
determines the extent of red coloring of hemoglobin
oxygen content
alterations in skin color (6)
-redness (erythema)
-pallor (blanching)
-cyanosis (bluish discoloration)
-jaundice (yellowing)
-bronzing
-bruises
Due to embarrassment, inflammation, hypertension, fever, or allergy
redness (erythema)
due to emotional stress such as fear, anemia, low blood pressure, impaired blood flow to an area
pallor (blanching)
Violet-ish lips and fingers from lack of oxygen
cyanosis
caused by liver disorder
jaundice (yellowing)
caused by Addison’s disease or iron medications
bronzing
hematomas
bruises
skin appendages (cutaneous glands)
sebaceous & sudoriferous glands
all exocrine glands
cutaneous glands
glands that produce oil (sebum), accumulated lipids and cell fragments
oil (sebaceous) glands
functions of oil
skin lubricant
prevents brittle hair
kills bacteria
most have ducts that empty into hair follicles; others open directly onto skin surface
oil (sebaceous) glands
activation of oil (sebaceous) glands
puberty
accumulated sebum blocks a sebaceous gland duct
whitehead
material oxidizes and dries
blackhead
an active inflammation of sebaceous glands accompanied by “pimple”
acne
caused by bacterial infection (Staphylococcus)
acne
overactive sebaceous glands
seborrhea
seborrhea in infants
cradle cap
glands that produce sweat, widely distributed in skin except nipples and parts of external genitalia
sweat (sudoriferous) glands
2 types of sudoriferous glands
eccrine (merocrine) & apocrine
- Numerous and abundant in the palms, soles of the feet and forehead
- Open via duct to pore on skin surface
- Produce sweat (clear)
eccrine (merocrine)
- Aprox. 2,000 are largely confined to the axillary and anogenital areas
- Ducts empty into hair follicles
- Begin to function at puberty
- Release sweat that also contains fatty acids and proteins (milky/yellowish color)
apocrine
apocrine glands (2)
ceruminous and mammary glands
modified glands found in the lining of external ear canal
ceruminous glands
ceruminous gland secretion mixes with sebum to produce
cerumen/earwax
glands that secretes milk (apocrine)
mammary glands
composition:
- Mostly water
- Salts & vit C
- Some metabolic waste
Fatty acids and proteins (apocrine only)
sweat
- Helps dissipate excess heat
- Excretes waste products
sweat
sweat’s ??? nature inhibits bacteria growth
acidic
sweat: odor is from associated ???
bacteria
produced by hair follicle
hair/pili
hair/pili consists of what epithelial cells
hard keratinized epithelial cells
provide pigment for hair color
melanocytes
hair grows in the matrix of ??? in stratum ???
hair bulb in stratum basale
hair anatomy
medulla, cortex, cuticle
hair anatomy:
- Consist of large cell and air spaces
- Only part of the hair that contains soft keratin, absent in fine hair
central medulla
hair anatomy: surrounds medulla
cortex
hair anatomy:
- Most heavily keratinized
- Provides strength and helps keep the inner layers tightly compacted
cuticle
Dermal and epidermal sheath surround hair root
hair follicle
Nipple-like bit of dermal tissue, protrudes into the hair bulb
hair papilla
Contains knot of capillaries that supplies nutrients to the growing hair and signals to grow.
hair papilla
Smooth muscle cells
Pulls hairs upright when cold or frightened
arrector pili muscle
Important role: contractions force sebum out of hair follicles to the skin surface where it acts as skin lubricant.
arrector pili muscle
types of hair growth
vellus and terminal hair
excessive hairiness that may results from adrenal gland/ovarian tumor
hirsutism
hair thinning & some degree of baldness
alopecia
most common, male pattern baldness
true/frank baldness
lanugo
fine hair
scale-like modifications of the epidermis; heavily keratinized
nails
(nail) stratum basale extends beneath the ??? and is responsible for growth
nail bed
lack of ??? makes the nails colorless
lack of pigment
proximal nail fold that projects onto the nail body
cuticle
root of nail is embedded in
skin
the visible attached portion of the nail
body
skin functions (6)
protection
body temperature regulation
cutaneous sensation
metabolic functions
blood reservoir
excretion
3 types of barriers
chemical, physical, biological barriers
barrier that include skin secretions and melanin
chemical barriers
chemical barriers
-dermcidin in sweat
-bactericidal in sebum
-defensins (natural antibiotics)
-cathelicidins
protective peptides in wounded skin
cathelicidins
natural antibiotics of skin
defensins
compared to bricks and mortar
stratum corneum
example barrier: stratum corneum
physical barrier
barrier: include dendritic cells of the epidermis, macrophages in the dermis and DNA
biological barriers
2 types of respirations for body temperature regulation
insensible and sensible respiration
respiration: external environment is cold, blood vessels constrict
sensible
function: skin is richly supplied with cutaneous sensory receptors, classified as exteroceptors
cutaneous sensation
richly supplied with cutaneous sensory receptors, classified as
exteroceptors
exteroceptors examples
tactile (Meissner’s) corpuscles
lamellar (Pacinian) corpuscles
function: Skin is a chemical factory fueled in part by the sun’s rays
metabolic functions
dermal vascular supply is extensive and can hold about how many percent of body’s entire blood volume?
5%
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals
burns
associated dangers in burns (3)
dehydration
electrolyte imbalance
circulatory shock
way to determine extent of burns
rule of nines
Body is divided into how many areas for quick estimation
11
TBSA for fatal
50-60%
TBSA for critical
35-49%
TBSA for emergency
35 below
Only epidermis is damaged
Skin is red and swollen
first-degree burns
○ Epidermis and upper dermis are damaged
○ Skin is red with blisters
second-degree burns
○ Destroys entire skin layer; burned area is painless
○ Burn is gray-white, cherry red or blackened
Little or no edema
third-degree burns
○ Over 25% of body has 2nd degree burns
○ Over 10% of body has 3rd degree burns
○ There are 3rd degree burns of the face, hands, or feet
critical burns
abnormal cell mass
skin cancer
classifications of skin cancer
benign and malignant
skin cancer that does not spread (encapsulated)
benign
skin cancer that metastasized (moves) to other parts of the body
malignant
most common type of cancer
skin cancer
skin cancer types
basal cell carcinoma
squamous cell carcinoma
malignant melanoma
Least malignant
Most common type
Arises from stratum basale
basal cell carcinoma
Metastasizes to lymph nodes if not removed
Early removal allows a good chance of cure
Believed to be sun-induced
Arises from stratum spinosum
squamous cell carcinoma
Cancer of melanocytes
Most deadly skin cancers
Metastasizes rapidly to lymph and blood vessels
Detection uses ABCD rule
malignant melanoma
ABCD rule
asymmetry
border irregularity
color
diameter
2 sides of pigmented mole do not match
asymmetry
borders of mole are not smooth
border irregularity
different colors in pigmented area
color
spot is larger than 6mm in diameter
diameter
