Integumentary System Flashcards
it includes the skin and accessory structures, such as hair, glands, and nails
integumentary system
skin is made up of two major tissue layers:
1.
2.
epidermis
dermis
what are the major functions of integumentary system
-
Protection. The skin is the covering of the body. Though
exposed to the external environment, the skin’s structure reduces
the negative and harmful effects of ultraviolet light. Acting as
a barrier, the skin also keeps microorganisms from entering
the body and prevents dehydration by reducing water loss. -
Sensation. The integumentary system has sensory receptors
that can detect heat, cold, touch, pressure, and pain. -
Temperature regulation. The skin plays a major role in
regulating body temperature through the modulation of blood
flow through the skin and the activity of sweat glands. -
Vitamin D production. When exposed to ultraviolet light, the skin
produces a molecule that can be transformed into the hormonal
form of vitamin D, an important regulator of calcium homeostasis. -
Excretion. Small amounts of waste products are excreted
through the skin and glands.
Skin
- Most superficial layer
- Stratified squamous epithelium
- In deepest layers, mitosis occurs
Epidermis
cells change shape and chemical
composition; cells become filed with the protein keratin
(hard)
keratinazion
transformation of the living cells of the stratum basale into the dead squamous cells of the
stratum corneum
keratinazion
deepest; cuboidal & columnar cells,
undergo mitosis every 19 days
stratum basale
most superficial stratum; dead squamous cells filled with keratin (structural strength);
lipids (prevent fluid loss); joined by desmosomes
stratum corneum
thickened area
callus
bony prominence, thickened corn shaped
structure
corn
- Dense collagenous connective tissue, contains
- fibroblasts, adipocytes, macrophages
- Nerves, hair follicles, smooth muscles, glands, lymphatic vessels
Dermis
structural strength
Collagen (resist stretching) & elastic fibers
collagen fibers are
oriented in some directions; skin is most resistant to
stretch along these lines
Cleavage lines/Tension lines
Cleavage lines/Tension lines
Stretch marks
contain blood vessels that supply the
epidermis with nutrients, remove waste products, and
regulate body temperature
dermal papillae
pigments responsible for skin, hair, eye color
melanin
produce melanin; irregularly shaped
cells; s. basale
melanocytes
vesicles derived from GA where
melanin is produced
melanosomes
Factors of Melanin Production
a. Genetic factors
b. Exposure to UV light
c. Hormones
recessive genetic trait that causes deficiency
/ absence of melanin
albinism
bluish skin color; decreased blood O2
Cyanosis
yellow pigment in plants (squash, carrots);
source of vitamin A
Carotene
congenital disorder of the capillaries in the
dermis
birthmark
- Attaches the skin to underlying bones
- Also called the hypodermis
- Loose connective tissue
- Storage of our body’s fat (padding, insulation)
Subcutaneous Tissue
Columns of dead, keratinized epithelial cells. Produced in the hair bulb
HAIR
where each hair rises
hair follicle
above the skin
shaft
root
below the skin
site of hair cell formation
hair bulb
hard keratin
cortex
soft central core
medulla
single layer of overlapping cells that holds the
hair in the hair follicle
cuticle
- Hair is formed by epithelial cells within the hair
- bulb
- Divide and undergo keratinization
- Hair root + shaft = columns of dead keratinized epithelial cells**
Growth stage
- Hair is held in the hair follicle. Growth stops
Resting Stage
A new hair is formed. The old hair falls out
Next growth stage
grow for about 30 days; rest for 105 days
eyelashes
– grow for 3 years; rest for 1 , 2 years
scalp hairs
smooth muscles; contraction = hair to
stand on end; produces goose bumps
arrector pilli
Simple, branched acinar glands. Connected by a duct to the superficial part of
the hair follicle
Sebaceous Glands
oily, white substance rich in lipids;
released by holocrine secretion; lubricates the
hair/surface of the skin (prevents drying and
protects against bacteria)
sebum
Ø Simple, coiled, tubular glands
Ø Release sweat by melocrine
secretion
Ø Numerous in the palms and soles
eccrine sweat glands
Ø Simple, coiled, tubular glands
Ø Produce a think secretion rich in
organic substances
Ø Released primary by melocrine
secretion; some glands demonstrate
holocrine secretion
Ø Open into hair follicles, in armpits
and genitalia
Ø Become active at puberty
apocrine sweat glands
cerumen (earwax)
Ceruminous glands
Mammary glands
milk
Dead stratum corneum cells. Contain a very hard type of keratin
nail
visible part of the nail
nail bed
part of the nail covered by skin
Nail root
§ Reducing water loss
§ Prevents microorganisms from entering the
body
§ Protects underlying structures against abrasion
§ Hair on head = insulator
§ Eyebrows = keep sweat out of the eyes
§ Eyelashes = protects the eyes from foreign
objects
§ Hair in the nose, ears = prevents the entry of
dust
§ Nails = protect the ends of the fingers, toes from
damage; can be used in defense
protection
Sensory receptors for pain, touch, hot, cold,
pressure
sensation
§ Skin exposed to UV light produces
cholecalciferol (modified in the liver, then in the
kidneys to produce active vitamin D)
§ Best sources of Vit. D = fatty fish, vit. D
fortified milk
§ Small amounts of Vit D = eggs, butter, liver
§ Active Vit. D stimulates the small intestine to
absorb calcium and phosphate (normal bone
growth, normal muscle function)
vitamin D production
§ Normal body temp. = 37
C (98.6 F)
§ Rate of chemical rxns within the body can
increased of decreased based on the body temp.
temperature regulation
Factors that raise body temperature
Ø Exercise
Ø Fever
Ø Increase in environmental
temperature
Ø Exercise
Ø Fever
Ø Increase in environmental
temperature
____ controls heat loss from the body
through dilation and constriction of blood
vessels
skin
________ produce sweat, which evaporates
and lowers body temperature
sweat glands
Heat is lost by ________ (infrared energy),
convection (air movement), ___________ (direct
contact)
radiation
conduction
Skin glands remove water and salt. Also removes small amounts of urea, uric acid,
ammonia
excretion
bluish color to the skin caused by decreased
blod O2 content
cyanosis
yellowish skin color caused by liver damage
(viral hepatitis)yellowish skin color caused by liver damage
(viral hepatitis)
jaundice
symptoms of problems elsewhere;
e.g. Scarlet fever causes reddish rash, allergic reaction to
food or drugs can develop rashes
rashes and lesions
excess keratin; sandpaper
texture characteristic
vit. A deficiency
nails become flat or concave
iron deficiency anemia
high levels of lead in the hair
Lead Poisoning
injury to a tissue caused by heat, cold, friction,
chemicals, electricity, and radiation
burns
§ S. basale remains viable;
§ Regeneration of the epidermis occurs within the
burn area
Partial-thickness burns
Ø Epidermis
Ø Red and painful
Ø Slight edema (swelling)
first degree burn
Ø Epidermis, dermis
Ø Epidermis regenerates from the
epithelial tissue
Ø Dermal damage is minimal;
v Redness, pain, edema, blisters
v Healing = 2 weeks
v No scarring
Ø Deep into the dermis
v Red, tan, or white
v Takes several months to heal
v Might scar
second-degree burn
Ø Epidermis, dermis, and underlying
tissues are completely destroyed
Ø Recovery occurs from the edges of
the burn wound
Ø Region of the 3rd degree burn is
painless (sensory receptors have
been destroyed)
Ø White, tan, brown, black, deep
cherry red
Ø Take a long time to heal
Ø Form scar tissue
Ø Skin grafts are used to prevent
complications and to speed healing
third-degree burn
§ Most common type of cancer
§ Exposure to UV light from the sun
§ Usually on face, neck, hands
§ Most like to have skin cancer = fair skinned or
older than 50
§ Limiting exposure to sun, using sunscreen;
reduces the likelihood of developing skin cancer
skin cancer
v Longer wavelength
v Causes most tanning of the skin
v Development of malignant
melanoma
UVA
v Most burning of the skin
v Development of basal cell and squamous cell carcinoma
UVB
§ Most frequent type
§ S. basale and extends into the dermis to produce
an open ulcer
§ Cure; surgical removal or radiation therapy
§ Little danger of cancer to spread, metastasize
basal cell carcinoma
§ Immediately superficial to the s. basale
§ Cells continue to divide as they produce keratin
= nodular, keratinized tumor confined to the
epidermis
§ Can invade the dermis, metastasize, and cause
death
squamous cell carcinoma
§ Rare form of skin cancer that arises from
melanocytes; usually from a pre-existing mole
§ Mole – an aggregation or nest of melanocytes
§ Large, flat, spreading lesion or deeply
pigmented nodule
§ Metastasis is common
§ Often fatal
malignant melanoma
§ Epidermis thins
§ Amount of collagen in the dermis decreases
§ Skin infections are most likely
§ Repair of skin occurs slower
§ Decrease no. of elastic fibers in the dermis and
loss of fat (sagging of skin, wrinkles)
§ Decrease of activity of sweat glands = reduced
ability to regulate body temp.
§ Decrease sebaceous gland activity = skin
becomes drier
§ Decrease no. of melanocytes
§ Some areas, the no. of melanocytes increase =
age spots
§ Increased melanin production = freckles; also,
gray/white hair
§ Skin that is exposed to sunlight = shows signs of
aging more rapidly
aging of skin in integumentary system
