integumentary system Flashcards
Integumentary
System
-The Integumentary
system includes:
◦Skin – largest organ
of the body
◦Accessory Organs:
Hair
Nails
-Serves to protect the
viscera (internal
organs) and regulate
temperature
Structure of the
Skin
1) epidermis
2) dermis
3) hypodermis
Epidermis
Outermost layer of skin
- Stratum Corneum– hard
outermost layer of epidermis
- Stratum Basale – produces new cells of epidermis
Stratum Corneum (epidermis)
hard outermost layer of epidermis
◦Produces a protein called keratin
◦Keratinization causes hardening of dead skin cells, making skin waterproof.
Stratum Basale (epidermis)
produces new cells of epidermis
◦Contains Langerhans cells (for immunity) and melanocytes (make pigment to give skin color)
Dermis
Thick layer of connective tissue containing the Dermal papillae and
collagen & elastic fibers- stretching & movement
◦Blood vessels
◦Sensory Nerves
◦Sebaceous Glands
◦Hair Follicles
Hypodermis (Subcutaneous
Layer)
Deepest layer of skin
Composed of loose
connective tissue and adipose tissue (fat)
◦Helps to store energy, insulate body, and provides protective padding
Five Functions of the
Skin
- Protection
- Regulates Water Loss
- Produces Vitamin D
- Gathers Sensory
Information - Regulates Body
Temperature
Functions of the
Skin- Protection
- Physical barrier to disease, dirt, and UV radiation
- Bacteria and other invaders are prevented entry by the top dead layer of skin and the acidic, oily secretion from sebaceous glands (sebum).
Functions of the
Skin- Regulates Water Loss
Keratinization of the dead skin outer layer also prevents water from entering or leaving the skin, even when immersed in water.
Skin works with the urinary
system to sweat off some excess water.
Functions of the
Skin- Produces Vitamin D
Melanocytes produce melanin to protect against harmful UV radiation from the sun and also to produce Vitamin D
Vitamin D helps regulate the
uptake of calcium by the digestive system.
Calcium is needed for strong bones.
Functions of the
Skin- Gathers Sensory
Information
Sensory receptors are linked to the nervous system
Receptors specialize in
sensing
◦Touch
◦Pressure
◦Pain
◦Temperature (hot & cold)
Many receptors in hands
Functions of the
Skin
When the body is too hot, the
skin will help to release heat
to cool the body temperature
back to 98.6°:
◦Sweat
◦Dilation of dermal blood vessels
When the body is too cold, the skin will help to raise body temperature back to 98.6° by generating heat:
◦Shivering (muscle contraction)
◦Goosebumps (contraction of
arector pili muscles attached to hair follicles) cause hair to trap heat
Hypothermia
Lower body temp. than normal interferes with the body’s normal functions and eventually ends in death
Hyperthermia
Higher body temp. than normal results in dehydration (from excess sweating) and heat stroke.
Skin Disorders
1. Chronic Disorders
2. Infectious
Disorders
3. Burns
4. Skin Cancers
Urticaria
(Hives)
◦Raised, often itchy,
red welts on skin surface
◦Usually due to an allergic reaction (to animal dander,
insect bites, pollen, shellfish, nuts, eggs, milk)
◦Also caused by caused by stress, extreme cold or hot, or illness
Eczema
Chronic skin disorder that
involves scaly and itchy rashes
Dry, flaky, blistering skin
appears red and inflamed
Intense itching and burning
sensations
Can be triggered by allergic
reactions to chemicals,
fabrics, heat, dryness
Dandruff (Seborrheic
dermatitis)
Caused by a yeast
White, flaky, inflammatory
skin condition
Often found on the scalp
Not contagious
Psoraiasis
-Flaky, silver-white patches called scales
-Redness and irritation
-Genetic
-The body produces too many new skin cells.
-Normally skin cell turn around is ~30 days, but with psoraiasis, turn over is around one week.
Albinism
Genetic disorder in which the body cannot produce melanin
Symptoms: absence of color in hair, skin, or iris; light
sensitivity; prone to sunburn
& skin cancer
Impetigo
◦Bacterial infection
◦Highly contagious
◦Causes blisters or sores on face and hands
◦Common among kids
Acne
Caused by an
overproduction of
sebum and oil, leading to clogging of the pores
Clogged pores trap
bacteria, dead skin
cells, and pus (white
blood cells)
Inflammation and swelling form red bumps
Pimples deep in the skin can form painful cysts
Other causes of acne
Genetics
Hormonal changes due to
menstrual cycles (females) or
stress
Greasy or oily cosmetic and hair products
Certain drugs (such as steroids, testosterone, estrogen)
High levels of humidity and
sweating
Diets high in refined sugars
Athlete’s Foot
Fungal infection
Very common on foot or other moist, warm areas of body
Fungus infects the upper
layers of the skin, causing
itching, cracking, and pain
Ringworm
Not a worm, caused by fungus
Occurs in warm,
moist areas with
frequent wetness
(such as from
sweating) and minor
injuries to your skin
Itchy, red, raised,
scaly patches that
may blister and ooze
Necrotizing Fasciitis
“Flesh-eating disease”
Very rare bacterial infection
Necrosis (death) of the
subcutaneous layer of skin
MRSA (Methicillin-Resistant
Staphylococcus aureus)
Staph infections are
caused by bacteria
Staphylococcus bacteria normally lives on the skin with
no problems
MRSA is a strain that
is resistant to antibiotics and
therefore very dangerous or deadly
Signs & Symptoms MRSA
People in hospitals are most likely to get MRSA
Staph skin infections start as small red bumps that resemble
pimples, boils or spider bites
Quickly turn into deep, painful abscesses that must be surgically drained
Sometimes the bacteria remain in the skin, but if it penetrates into the body, it can be life-threatening
Skin Burns
A burn is tissue damage
which destroys cell proteins
and cause cell death in the
affected areas
Caused by:
◦Heat
◦Radiation (sunlight, tanning
beds)
◦Chemicals
◦Electricity
Degrees of Burns- 1st
Degree Burn
◦Burns only the epidermis (ex.Sunburn)
◦Redness & Pain, no blistering
Degrees of Burns- 2nd
Degree Burn
Burns occur in the epidermis
and some of the dermis
Redness, Pain, & blistering
Degrees of Burns- 3rd
Degree Burn
The epidermis, dermis, and
hypodermis are destroyed
Damage to the nerve endings
(ex. Exposure to direct fire)
Extent of Burns
“Rule of Nines”
◦Body is divided into 11 regions
(each accounting for 9% of total body area)
Critical Burns
◦Cover more than10% of
the body’s surface area
◦Burns on face, genitals,
or completely encircling
the hands or feet
Treatment of Critical
Burns
Complications:
◦Infection, hypothermia,
dehydration
Intense doses of intravenous fluids to replace electrolyte imbalance
Warm and isolated
environment to reduce risk of
infection
Skin graft can be done as
soon as patient is stable
Skin Cancer
Risk Factors
◦Age (Older people)
◦Light-skin
◦Excessive sun exposure
◦Genetics (family history)
◦Chemical exposure
When to see your doctor:
◦If you have any of the warning signs, are older, or have a family history of skin cancer
Cancer
abnormal division of a cell that has undergone a DNA mutation
Tumor
mass of mutated cells
Metastasis
the spread of cancer cells from one part of the body to another
Two Categories of Skin
Cancer
◦1) Non-Melanoma
Includes Basal cell
carcinoma and
Squamous cell
carcinoma
◦2) Melanoma
Basal Cell Carcinoma
Most common skin cancer
Occurs – in sun-exposed areas
Appearance – pearly or waxy bump or a flat, flesh-colored or brown scar-like legion
Treatment – cryosurgery,
surgical removal
◦95% of patients easily cured,
but it may come back
Squamous Cell
Carcinoma
Five times less common than basal cell carcinoma, but more likely to spread to nearby organs
Occurs – on sun-exposed areas
Appearance – firm, red nodule or a flat lesion with a scaly, crusted surface
Treatment – cryosurgery,
surgical removal,
Melanoma
Most dangerous skin cancer because it can metastasize (spread) and lead to death
Occurs – anywhere on body’s skin
Appearance – large brownish spot with darker speckles or a mole that
changes in color, size or bleeds
◦Men – on trunk, head or neck
◦Women – lower legs
Treatment – surgical removal, radiation, chemotherapy
