GETTING UNDER YOUR SKIN
What do you think this means...?Right now you are wearing an air-conditioner, a blanket, a thermometer, a garbage disposal, a waterproof suit, a chemical factory and an oil refinery.
Two Layers of SkinEpidermis (outermost covering) Made of epithelial cells Is avascular (no blood vessels)
Dermis (true skin) Made of connective tissue Is vascular (has blood vessels)
Layers of the EpidermisSquamous Germination Innermost epidermal layer Active layer of cell division (mitosis) Continually reproduces and new cells move toward the surface (allows skin to self-repair)
Stratum Corneum (outermost layer) Horny layer of skin (cells are dead) Keratin replaces cytoplasm in the cells as they approach the surface (waterproofs the skin) Slightly acidic destroys many organisms first line of defense against surface bacteria
Layers of the Epidermis (continued)3. Pigment Layer Layer that contains melanocytes which produce the brown pigment melanin that give the skin its color Ultra-violet rays produce an increase in melanin = tan or sunburn Albinism absence of melanin Freckles patches of melanin
We get a new outer skin layer every 27 days!
Flat and scale-like cells of the stratum corneum flake off
Dermis Layer (Corium or True Skin)Thicker, inner layer of skin Framework of elastic connective tissue (enables skin to stretch) Number of elastic fibers and collagen decrease with age = wrinkles, sags, and linesContains blood vessels, nerves, involuntary muscle, sweat and oil glands, and hair folliclesSensory nerves end in nerve receptors which are sensitive to heat, cold, touch, pain, and pressure
Dermal PapillaeRidges and grooves in upper layer of dermis that push into the stratum germinativum (Unique to each person)Create permanent ridges in fingers, palms, and soles of feetProvides maximum resistance to slipping when grasping and holding objectsRidges create fingerprints used in identification
Subcutaneous Tissue or Hypodermal Layer Lies under the dermis and carries major blood vessels and nerves to the skin above it Made up of loose connective tissue (adipose) and contains about of the bodys stored fatConnects skin to underlying muscles
3 Function of Subcutaneous TissueCushions the body
Insulates the body
Site of subcutaneous injections (large blood vessels)
Sudoriferous (Sweat Glands)
Approximately 3 million sweat glands throughout the body Most are found under the arms (axilla), palms of hands, soles of the feet, and foreheadThey are tubular with a coiled base in the dermis and a tube-like duct which extends to form a pore in the epidermisWater filters through the thin walls from surrounding tissue Water is mixed with small amounts of waste material such as ammonia and uric acid
Sudoriferous (Sweat Glands)These glands can be activated by heat, pain, fever, and nervousness
On an average summer day, these glands will pump out about 2 quarts of fluid
Sudoriferous Glands Two TypesEccrine Produces perspiration and functions throughout life Assists in body heat regulation Perspiration is 99% water and average fluid loss is 500 ml.per day2. Apocrine (larger than eccrine glands) Found in axilla and genitalia Enlarges and begins to function during puberty Secretes a thick milky secretion Skin bacteria breaks these secretions and causes the odor you smell
Sebaceous Glands (Oil Glands)Secretes oil or sebum for hair and skin which protects your hair and skin from drying outMakes skin waterproofThese glands increase five-fold between ages 10-19Usually opens onto a hair follicle
Plugged Sebaceous GlandsPlugged sebaceous glands (oil glands) will produce blackheads or pimplesAcne Vulgaris is an inflammation of sebaceous glands
HairMillions cover the bodyAnatomy of a hair: Root part of the hair implanted in the skin Shaft part of the hair which projects from the skin Hair Follicle epidermal tube-like structure that holds the hair root (extension of the epidermis deep into the dermis) Papilla tuff of tissue at the bottom of the follicle that contains blood vessels Hair Bulb Where hair growth starts
Hair Follicle Outer layer = cortex Inner layer = medulla
How Hair Grows (Cycles)Hair is produced in the hair bulbBlood vessels in the papilla supply the hair bulb with nourishmentDivision of cells in the hair follicle gives rise to new hairThese cells divide and undergo keratinizationHair grows longer as cells are added to the base of the hair root
Critical Thinking Based on your knowledge of hair growth cycles, why does your hair grow back when you use products such as Nair to get rid of hairs on your body?
How Hair GrowsAs long as cells in the papilla of the hair follicle remain alive, new hair will replace any that is cut or plucked.
How Hair Grows Alopecia Hair loss of any kind.
Arrector Pili MuscleInvoluntary muscle that attaches to the lower end of the hair follicle near the bulb and the other end is attached to connective tissue in the dermisProduces goose pimples or goose bumps to trap heat and keep the body warm
NailsNail is formed in the nail bed or matrixEpidermal cells fused together and fill with keratin
7 Functions of the Integumentary SystemProtective coveringRegulates body temperatureManufactures Vitamin DSensory FunctionTemporary storage of fat, glucose, water, and saltsScreens out harmful ultraviolet readiationAbsorbs certain drugs
Skin and MicroorganismsIntact skin = best protection against pathogens, toxins and water lossSkin generally too dry for microbial growth they do grow in moist areasMost skin bacteria associated with hair follicles or sweat glandsUnderarm perspiration odor caused by bacteria and perspiration
The best way to prevent the spread if disease is by hand washing
First Degree Burns Involves only the epidermis Sunburn is an example Symptoms: redness, pain, and small amount of swelling Treatment apply cool water and analgesics for pain Healing Time: 3 6 days and tissue destructions is minimal
BurnsSecond Degree BurnMay involve the epidermis and the dermisSymptoms: Pain, swelling, redness and blisters (Skin may be exposed to infection)Treatment: Pain medication and dry sterile dressing over open skin areas (DO NOT POP THE BLISTERS!)Healing Time 2-3 weeks with minimal cosmetic defects ( May have change in skin color or pigmentation)
BurnsThird Degree BurnsDestruction of the epidermis, dermis and sometimes the subcutaneous layerCan involve underlying muscles and even bonesSymptoms: loss of skin, eschar, and there may be no pain due to damaged nervesMay be life- threatening damage depending on the amount of skin and fluid loss, as well as plasmaTreatment: Immediate hospitalization Prevent infection and skin contractures Fluid replacement Skin grafts as soon as possible
Rule of NinesTreatment and possibility of recovery from burns depend on the total body area affected and the severity of the burn
It is used to measure the percent of the body burned.
Rule of NinesThe body is divided into 11 areas and each area accounts for 9% of the total body surfaceMajor Burns: Second degree over 25% of adult body surface area (b.s.a.) or more than 20% of a childs body surface area Third degree burn over more than 10% of adult body surface area.
Practical ApplicationPatrick was involved in a fire when his race car crashed. He burned his face, entire right arm, back, buttock, and front of right leg. What percent of his body was burned?
Now, do you know what this means?Right now you are wearing an air-conditioner, a blanket, a thermometer, a garbage disposal, a waterproof suit, a chemical factory and an oil refinery.