Week 5: Integumentary System Flashcards
***Integumentary System & General Function
- Skin: largest organ in body
- Accessory Organs:
- Hair
- Nails - Glands
Function: Serves to protect the viscera (internal organs) and regulate temperature
***Integumentary System Layers
3 Layers:
- Epidermis
- Dermis
- Hypodermis
***Epidermis: Location, Structure, and Function
Location:
Outermost layer of skin
Structure/ Function:
-Stratum Corneum – hard outermost layer of epidermis
Produces a protein called keratin
Keratinization causes hardening of dead skin cells, making skin waterproof.
Stratum Basale – produces new cells of epidermis
Contains Langerhans cells (for immunity) and melanocytes (make pigment to give skin color)
***Dermis: Location, Structure, and Function
Location: middle layer of skin
Structure:
Thick layer of connective tissue containing:
-Dermal papillae – ridges (epidermal waves) that cause fingerprints and provide gripping surface
-Collagen & elastic fibers – stretching & movement
-Blood vessels
-Sensory Nerves/ Nerve Endings
-Sebaceous Glands
-Hair Follicles
Function:
- stretching and movement (collagen/ elastic fibers)
- sensation
- gripping surface (dermal pappilae)
- nutrient exchange
- secretion/ absorption
Keratinization
causes hardening of dead skin cells, making skin waterproof & protective of foreign invaders
Hypodermis
Also known as the subcutaneous tissue
Location:
-Deepest layer of skin
Structure:
-Composed of loose connective tissue and adipose tissue (fat)
Function:
-Helps to store energy, insulate body, and provides protective padding
***Functions of Skin/ Integument
- Protection
- Regulates Water Loss
- Produces Vitamin D
- Gathers Sensory Information
- Regulates Body Temperature
- Nonverbal Communication
Function of 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).
Function of skin: Regulates Water Loss
-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
Constriction of dermal blood vessels
Lack of homeostasis in body temp:
- 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.
Function of 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 the extremities ie hands
Function of 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.
Function of 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.
Skin Disorder Types:
- Chronic
- Infectious
- Burns
- 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 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
MRSA
- MSRA = 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
MSRA Stands For..
Methicillin-Resistant Staphylococcus aureus
MSRA: Signs & Symptoms
- 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: Attributes & Causes
-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
**Degress of burns:
1st Degree Burn
2nd Degree Burn
3rds Degree Burn
Are tanning beds safe ?
The salons say yes, but studies show tanning beds still increase the risk of cancer
***2nd Degree Burn
Burns occur in the epidermis and some of the dermis
Redness, Pain, & blistering
***1st Degree Burn
Burns only the epidermis (ex. Sunburn)
Redness & Pain, no blistering
***3rd Degree Burn
The epidermis, dermis, and hypodermis are destroyed
Damage to the nerve endings (ex. Exposure to direct fire)
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
Critical Burn Complications
-Complications: Infection, hypothermia, dehydration
Crticial Burn Treatment
- 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
***Skin Cancer: When to see your doctor?
If you have any of the warning signs, are older, or have a family history of skin cancer
Cancer Definition
abnormal division of a cell that has undergone a DNA mutation
Tumor Definition
mass of mutated cells