CBIO 2200: Exam 2
149 Cards in this Set
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integumentary system
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includes skin, hair, nails, cutaneous glands, and sweat glands.
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dermatology
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the study of the skin.
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skin
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is the largest, most exposed organ. exposed to U V radiation and chemicals. Skin is the most treated organ. There are 2 layers to the skin.
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functions of skin
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resistance to trauma, resistance to infection, vitamin D synthesis, sensation, thermoregulation, nonverbal communication, transdermal absorption.
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layers of the skin
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the epidermis is the outer layer.
the dermis is underneath the epidermis.
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epidermis
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outer layer of the skin made of keratinized stratified squamous epithelium. The epidermis lacks blood vessels.
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dermis
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connective tissue layer of the skin directly below the epidermis. the dermis contains blood vessels, sweat glands, sebaceous glands, and nerve endings.
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thickness of most skin
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most skin is 1-2 millimeters thick, but ranges from 0.5 millimeters thick on the eyelids to 6 millimeters thick between the shoulder blades.
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hypodermis
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the hypodermis is not actually part of the skin. it is the subcutaneous layer where we inject medicines. The hypodermis contains mostly adipose and areolar connective tissue as well as good blood supply and nerve endings.
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thick skin
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is found on the palms of the hands and soles of the feet. Thick skin does not have hair follicles or sebaceous glands but it does have sweat glands.
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thin skin
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is found everywhere on the body except the palms and soles. Thin skin has sweat glands, hair follicles, and sebaceous glands.
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layers of the epidermis
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from superficial to deep: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale. The stratum lucidum is only found in thick skin.
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stratum corneum
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most superficial layer of the epidermis consisting of up to 30 layers of dead, scaly, keratinized cells that form a durable surface layer. It is especially resistant to abrasion, penetration, and water loss.
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stratum lucidum
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2nd most superficial layer only found in thick skin. It is very thin and is translucent due to the clear protein eleiden that is densely packed in the keratinocytes of this layer.
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stratum granulosum
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3rd deepest layer of the epidermis, just above the stratum spinosoum, consists of 3 to 5 layers of flat keratinocytes that contain dark-staining keratohyalin granules that this layer is named for. The granules have a functional role.
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stratum spinosum
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2nd deepest layer of the epidermis. In this layer, the keratinocytes begin producing keratin and the cells flatten out and cease dividing.
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keratohyalin granules
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dark-staining material in the keratinocytes of the stratum granulosum.
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stratum basale
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deepest layer of the epidermis. consists mainly of a single layer of cuboidal to low columnar stem cells and keratinocytes resting on a basement membrane. The stem cells give rise to the keratinocytes that rise up through the other layers to be eventually sloughed off.
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epidermolytic hyperkeratosis
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keratin defect in which the keratin clumps up. This makes skin less waterproof than normal and victims are susceptible to dehydration and sepsis which means invasion by micro-organisms.
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melanocytes
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melanocytes are found only in the stratum basale amid the stem cells and the deepest keratinocytes. melanocytes synthesize melanin.
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merkel or tactile cells
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tactile cells are relatively few in the epidermis and are receptors for touch. they are found in the stratum basale.
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dendritic or Langerhanns cells
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are found in the stratum spinosum and the stratum granulosum. They are the immune cells of the skin.
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dermal papillae
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extensions of the dermis that reach into the epidermis. the dermal papillae create the ridges that form our fingerprints.
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2 layers of dermis
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papillary layer - thin layer of areolar tissue with more blood vessels than reticular layer.
reticular layer- consists of dense irregular connective tissue and is beneath the papillary layer.
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piloerector muscles
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when contracted, they make hair stand on end and the skin to wrinkle causing goose bumps.
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3 pigments which contribute to skin color
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melanin, which includes eumelanin and pheomelanin.
hemoglobin, and carotene.
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melanin
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most significant skin pigment produced by melanocytes in which it accumulates. Found in the stratum basale and stratum spinosa.
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eumelanin
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brownish black melanin pigment.
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pheomelanin
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reddish to yellow melanin pigment.
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hemoglobin
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red blood cells affect skin color and imparts a reddish to pinkish hue.
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carotene
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is the yellow pigment from egg yolks and is also found in vegetables. Depending on the diet, carotene can become concentrated in the subcutaneous fat and cause a yellowish color.
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skin color
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is not related to the number of melanocytes but instead is due to how they are packaged. Spread out melanocytes produce a darker color while clumpy melanin leads to a lighter color. UV radiation causes the pigment to spread out more.
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cyanosis
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blueness of the skin resulting from a deficiency of oxygen in the circulating blood.
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erythema
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abnormal redness of the skin that may be caused by exercise, hot weather, sunburn, anger, and embarrassment.
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pallor
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a pale or ashen color that occurs when there is little blood flow to the skin. Often, people will loose all color right before they die.
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albinism
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a genetic lack of melanin that results in milky white hair and skin, and blue-gray eyes. It is a recessive disorder caused by a defective enzyme--tyrosinase.
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tyrosinase
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enzyme required for the production of melanin from the amino acid tyrosine. if this enzyme is defective, albinism results.
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jaundice
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yellowing of the skin and sclera resulting from high bilirubin levels in the blood.
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bilirubin
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a hemoglobin breakdown product that can cause yellowing of the skin and sclera if it builds up in the blood. This yellowing is called jaundice.
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hematoma
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a bruise or mass of clotted blood.
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pilus
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correct name for hair--a slender filament of keratinized cells that grows from an oblique tube in the skin called a hair follicle.
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pili
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plural form or pilus
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hair conditioner
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works by smoothing the outer layer of the hair, which is called the cuticle and resembles shingles on a roof.
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split ends
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occurs when the cells of the cuticle layer of a hair filament pull apart.
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zones of hair
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the bulb, the root, and the shaft.
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bulb
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is found at the bottom of the hair follicle and is the only part of a hair with living cells that are actively dividing.
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root
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is the portion of the hair between the bulb and the skin surface.
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shaft
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is the part of the hair that protrudes from the skin.
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layers of hair
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medulla, cortex, cuticle
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medulla
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middle layer of the hair made up of soft keratin.
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cortex
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surrounds the medulla.
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cuticle
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this is the shingle layer on the outside of the hair. it contains hard keratin and is transparent. If the cells of the cuticle separate you have split ends.
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structure of hair follicle
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-the outer connective tissue sheath.
-the inner epithelial root sheat.
-the dermal papilla extend to the follicle to nourish the hair.
-hair matrix is the area of the bulb where cells are actively dividing.
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hair color
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depends on melanin! Brown/black hair contains more eumelanin while red hair contains more pheopmelanin. White and gray hair is usually due to a lack of melanin or air in the medulla.
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3 kinds of hair
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lanugo, vellus, and terminal hair.
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lanugo
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only found in infants--it is the fine hair that covers babies and is usually gone by around 3 months of age.
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vellus
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is found on the bodies of children and females. Vellus is fine, pale hair.
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terminal hair
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coarser hair found in eyebrows, scalp, men's facial hair, groin, and axillary region.
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cycle of hair growth
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hair proceeds through anagen, categen, and telogen
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anagen stage
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in this stage the hair is actively growing.
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late anagen stage
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the end of the anagen stage in which the hair separates from the dermal papilla. The anagen phase may last 6 to 8 years.
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catagen stage
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the hair is dying and is now called a club hair because it is detached. this phase lasts 2 to 3 weeks.
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telogen stage
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the dermal papilla begins to ascend and nourish a new hair, which may begin to grown alongside the dead club hair. This stage may last 1 to 3 months.
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hair cycle and aging
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as we age, hair follicles may not proceed from telogen back to anagen. this causes permanent hair loss.
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alopecia
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hair loss not associated with old age. Alopecia may e cause by malnutrition, and medication. Minoxidil may reverse alopecia.
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eponychium
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correct name for the cuticle of a nail.
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hyponychium
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the skin directly under the nail sometimes called the nail bed.
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5 types of cutaneous glands
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merocrine sweat glands, apocrine sweat glands, sebaceous glands, ceruminous glands, and mammary glands.
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2 kinds of sweat glands
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merocrine sweat glands and apocrine sweat glands.
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merocrine sweat glands
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produce sweat secretions by exocytosis and are widely distributed all over the body--especially the palms, soles, and forehead. They have myoepithelial cells which allow them to contract and push sweat up the sweat duct.
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apocrine sweat glands
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produce sweat secretions by exocytosis and are associated with the axillary and groin area. The sweat from these glands includes a scent called a pheromone.
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sebaceous glands
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oil producing glands found everywhere except thick skin. sebaceous glands secrete sebum. Note that most skin lotions are just sheep sebum which has been given the fancy name lanolin.
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ceruminous glands
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specialized sweat glands found only in the ear canal. Their secretions combine with sebum and dead skin to produce cerumin which is commonly known as ear wax.
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mammary glands
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modified apocrine sweat glands fully developed in female breasts during pregnancy and lactation. the duct cells look different at different stages.
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skin cancer
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Skin cancer is induced by rays of the sun.
Skin cancer is the most common cancer and the most treatable cancer.
Skin cancer is often found in the head and neck area.
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3 types of skin cancer
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basal cell carcinoma, squamous cell carcinoma, malignant melanoma.
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basal cell carcinoma
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the most common type of skin cancer starts out as small blister and is 99% curable. Basal cell carcinoma affects the cells of the stratum basale and seldom metastasizes.
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squamous cell carcinoma
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is the second most common type and affects keratinocytes in the stratum spinosum. It starts out as an ulceration with a concave center and squamous cell carcinoma will tend to metastasize to the lymph nodes.
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malignant melanoma
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skin cancer that arises from melanocytes and metastasizes rapidly. Malignant melanoma is usually unresponsive to chemotherapy once it metastasizes and is usually fatal. Only 5 to 14% of malignant melanoma patients survive 5 years from diagnosis.
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A B C D Rule of Skin Cancer
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A refers to asymmetry--asymmetrical moles are suspicious.
B refers to border--a ruffled bordered moles is suspicious.
C refers to color--a multicolored mole is suspicious.
D refers to diameter--a mole larger than 6 millimeters is suspicious.
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Burns
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are the leading cause of accidental death--most victims die from infection or dehydration. The severity of a burn is measured by the percent of the body involved and the degree, or depth, of the burn.
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Rule of Nines
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used to estimate the percentage of the body involved in a burn. The anterior and posterior head and neck are 4.5% each. The anterior and posterior arm are 4.5% each times 2 arms. The anterior and posterior trunk are 18% each. The anterior and posterior leg are 9% each. The perineum or gro…
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Degrees of Burn
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measures the severity based on the skin layers involved in the burn. 1st and 2nd degree burns are partial thickness burns. 1st degree involves only part but not all of the epidermis. 2nd degree involves the epidermis and part but not all of the dermis. 3rd degree involves the epidermis, t…
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Treating 3rd Degree Burns
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-must be covered by some sort of skin graft to protect from infection and dehydration
-eschar must be removed by debridement every 5 to 7 days to prevent infection
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Eschar
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dead skin that develops on a burn and must be removed by debridement every 5 to 7 days to prevent infection
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autograft
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uses skin from the burn victim for a skin graft. not possible when a large part of the body is involved in the burn.
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isograft
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uses skin from an identical twin of the burn victim for a skin graft.
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cadaver graft
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a homograft that uses skin from a cadaver.
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allograft
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another name for homograft--these grafts use skin from a person that is not an identical twin of the burn victim.
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homograft
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also called an allograft, these grafts use skin from a person that is not an identical twin of the burn victim.
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heterograft
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skin graft made from skin from another species. this is also called a xenograft.
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artificial skin
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made from silicone and collagen in a lab.
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Osteoology
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the study of bones
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Skeletal System
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is composed of bones, cartilage, ligaments, tendons, and teeth
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living skeleton
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refers to the fact that our skeletons are metabolically active
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functions of skeleton
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support, protection, movement, electrolyte balance, acid-base balance, and blood formation.
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osseous tissue
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another name for bone--it is a connective tissue in which the matrix is hardened by deposition of calcium, phosphate, and other minerals.
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4 categories of bones
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long bones, flat bones, short bones, and irregular bones.
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long bones
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these are the most important bones in body movement--these are the long bones in the limbs: humerus, radius, ulna, femur, tibia, fibula
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diaphysis
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the shaft of a long bone. the diaphysis provides leverage.
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epiphysis
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the expanded head of a long bone. the epiphysis strengthens the joint and provides room for attachment of tendons and ligaments.
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spongy bone
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a more loosely organized osseous tissue found in the central spaces of the epiphysis. Spongy bone is surrounded by compact bone. spongy bone is also called cancellous bone. Parts of spongy bone are called tribeculae and speculae.
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marrow cavity
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more of a soft tissue, the marrow cavity contains the bone marrow and is also called the medullary cavity.
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articular cartilage
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hyaline cartilage found at joint surfaces
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nutrient foramina
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these are minute holes that allow blood vessels to penetrate into the bone
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periosteum
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sheath that covers the outside of bones and is made up of two layers: an outer fibrous layer made mostly of collagen and an inner osteogenic layer that rests right on the bone and contains the stem cells.
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endosteum
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a thin layer of reticular connective tissue that lines the internal marrow cavity, covers all the honeycombed surfaces of spongy bone, and lines the canal system.
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2 layers of periosteum
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-outer fibrous layer made of collagen.
-inner osteogenic layer that has the stem cells which can become osteoblasts and osteocytes.
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epiphyseal plate or growth plate
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is made of hyaline cartilage in children and adolescents and allows for lengthening of long bones; in adults the plate has hardened and can no longer allow growth. The epiphyseal plate closers earlier in females due to their hormonal makeup.
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flat bones
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most of the cranial bones, the sternum, scapula, ribs, and hip bones are flat bones consisting of a layer of spongy bone sandwiched between layers of compact bone.
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4 types of bone cells
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osteogenic cells, osteoblasts, osteoclasts, and osteocytes
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osteogenic cells
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stem cells of osseous tissue and are found in the inner layer of the periosteum, in the central canals, and in the endosteum. They develop from embryonic mesenchymal cells and give rise to most other bone cell types. They multiply continually and some go on to become osteoblasts.
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osteoblasts
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are bone-forming cells that come from osteogenic cells and synthesize the soft organic matter of the bone matrix which hardens by mineral deposition. osteoblasts do not divide.
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osteocytes
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are former osteoblasts that have become trapped in the matrix they deposited--residing in tiny cavities called lacunae which are connected by canals called canaliculi
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osteoclasts
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bone dissolving cells found on the bone surface; osteoclasts are of the monocyte/macrophage blood cell line. osteoclasts are multi-nucleated and have a ruffled border which secretes H+ ions and increases the surface area. Osteoclasts liberate calcium, phosphorous, and other minerals.
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general composition of bone
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1/3 organic--collagen matrix synthesized by osteoblasts.
2/3 inorganic-calcium, phosphate, fluoride, etc.
collagen gives bones flexibility while mineralization gives them strength.
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function of collagen in bone
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allows bones to have some flexibility; however, without mineralization bones would be too flexible to function.
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function of bone mineralization
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allows bones to be hard and rigid; however, without collagen, bones would be so hard and brittle that they would crack easily.
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rickets
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disease caused by vitamin D deficiency that leads to very soft bones that bend easily; rickets is like osteoporosis on crack.
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osteogenesis imperfecta
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is also known as brittle bone disease and is the result of a collagen deficiency. we now have a treatment for this disorder.
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histology of compact bone
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reveal a concentric lamellae arranged around a central canal that is also called a haversian or osteonic canal. a central canal and it's lamellae constitute an osteon; canaliculi connect the lamellae. central canals are joined by perforating canals, AKA Volkmann canals.
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children's bone marrow
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children have mostly red bone marrow.
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adult bone marrow
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adults have mostly yellow bone marrow. Adults' red bone marrow is limited to skull, vertebrae, ribs, sternum, part of the pelvic girdle, and the proximal heads of the humerus and femur.
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yellow bone marrow
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is made mostly of adipose tissue and does not produce blood cells. however, in a state of anemia, yellow bone marrow can be transformed back to red marrow.
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red bone marrow
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is also known as myeloid tissue and is described as homopoietic tissue--tissue that produces blood cells.
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skin provides resistance to trauma and infection
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-keratin provides waterproofing.
-skin pH is 4 to 6: this is called the acid mantle and protects us from bacteria.
-protects internal organs from UV radiation.
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acid mantle
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refers to skin pH of 4 to 6. This is an inhospitable environment to bacteria and protects us from infection.
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skin and vitamin D synthesis
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the skin is responsible for the first step in vitamin D synthesis. The liver and kidneys complete the process.
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skin helps with thermoregulation
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vasodilation helps disperse body heat while vasoconstriction helps retain body heat. the sweat glands activate with increased temperature and evaporation of sweat helps cool the body.
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keratinocytes
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the great majority of epidermal cells are keratinocytes.
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cells of the stratum basale
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stem cells, keratinocytes that are actively dividing, melanocytes which are producing melanin in this layer, and merkel or tactile cells.
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stretch marks
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are due to the stretching and tearing of the collagen fibers in the dermis.
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bromohidrosis
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disagreeable body odor resulting from bacteria feeding on the secretions from apocrine sweat glands.
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sebum
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secretion of sebaceous glands.
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lanolin
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sheep sebum used in skin lotions.
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short bones
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mainly the bones of the wrists and ankles--carpals and tarsals; the patella is also a short bone.
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compact bone
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is also called dense bone and covers spongy bone.
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diploe
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layer of spongy bone in the cranium that absorbs impact and helps prevent injury to the brain.
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remodeling
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occurs in response to physical demands placed on bones and is a constant process. recall Dr. William's crutches example.
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function of osteoclasts
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the H+ ions secreted at the osteoclasts' ruffled border naturally attracts chloride ions to form hydrochloric acid that is used to dissolve the bone matrix. osteoclasts have to be activated before they will resorb bone.
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ossification
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AKA osteogenesis, is the formation of bone. Ossification occurs throughout life.
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2 methods of fetal bone development
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1. intramembranous ossification.
2. endochondral ossification.
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intramembranous ossification
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embryonic connective tissue is replaced with flat bone; 4 steps: condensation of mesencymal tissue and osteogenic cell formation; differentiation into osteoblasts; trabeculae formation; solidification of surface into compact bone
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first step in intramembranous ossification
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some of the embryonic connective tissue (mesenchyme) condenses into a layer of soft tissue with a dense supply of blood capillaries. The mesenchymal cells enlarge and differentiate into osteogenic cells, and regions of mesenchymy become a network of soft sheets called trabeculae.
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second step in intramembranous ossification
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osteogenic cells gather at the trabeculae and differentiate into osteoblasts. They deposit an organic matrix called osteoid tissue. As the trabeculae become thicker, calcium phosphate is deposited into the matrix. Some osteoblasts are trapped and become osteocytes. Mesenchyme close to the…
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third step in intramembranous ossification
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osteoblasts continue to deposit minerals, producing a honeycomb of bony tribeculae. Some trabeculae persist as permanent spongy bone, while osteoclasts resorb and remodel others to form a marrow cavity in the middle of the bone.
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fourth step in intramembranous ossification
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trabeculae at the surface continue to calcify until the spaces between them are filled in, converting the spongy bone to compact bone. This is how the sandwich-like flat bone arise.
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endochondral ossification
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development of long bones on an early hyaline cartilage model; ossification begins around week 12 of fetal development; 6 steps: mesenchyme develops into hyaline cartilage in the location of a future bone; osteoblasts deposit the bony collar which becomes the primary ossification center; …
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first step in endochondral ossification
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mesenchyme develops into a body of hyaline cartilage, covered with a fibrous perichondrium, in the location of future bone. For a time, the perichondrium produces chondrocytes and the cartilage model grows and thickens.
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CBIO 2200: Exam 1