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25 Cards in this Set
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- Back
- 3rd side (hint)
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Skin (Integument) |
-Largest organ in body, makes up 16% of total body weight -major component of nonspecific immune defense, protecting us from elements & invasion by pathogens -helps maintain osmolarity of body |
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Layers of skin |
Dermis, epidermis, hypodermis (subcutaneous layer) |
Skin derived from ectoderm |
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Epidermis |
-Subdivided into layers called strata -Stratum basale, stratum spinosum, stratum ganulosum, stratum lucidum & stratum corneum (from deepest layer outward) |
Come Let's Get Sun Burned |
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Stratum basale |
Contains stem cells and is responsible for proliferation of keratinocytes, predominant cells of skin produce keratin |
Epidermis |
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Stratum spinosum |
Cells Connected to each other , site of Langerhans cells |
Epidermis |
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Stratum granulosum |
Keratinocytes die & lose their nuclei |
Epidermis |
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Stratum lucidum |
Present in thick, hairless skin such as the skin on the sole of the foot or the palms & nearly transparent. |
Epidermis |
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Straum corneum |
Contains up to several dozen layers of flattened keratinocyte, forming a barrier that prevents invasion by pathogen & helps prevent loss of fluids & salt |
Epidermis |
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Calluses |
Form from excessive keratin deposition In areas of repeated strain due to friction, provide protection from future damage. |
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Fingernails & hair |
Also formed by keratin |
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Melanocytes |
Derived from neural crest cells found in stratum basale |
Produce melanin |
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Melanin |
Pigment that serves to protect skin from DNA damage caused by UV |
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Langerhans cells |
Capable of presenting antigens to T-celss in order to activate immune response |
Special macrophages |
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Dermis |
Upper layer right below the epidermis (papillary layer)-comsist of loose connective tissue. Lower layer (reticular layer) |
Sweat glands, bloods vessels & hair follicles originate here |
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Merkel cells (discs) |
Cells connected to sensory neurons and are responsible for deep pressure & texture sensation within skin. |
Located in dermis |
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Meissner's corpuscles |
Respond to light touch |
Located in dermis |
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Ruffini endings |
Respond to stretch |
Located in dermis |
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Pacinian corpuscles |
Respond to deep pressure & vibration |
Located in dermis |
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Hypodermis |
Layer of connective tissue that connects the skin to the rest of the body. |
Contains fat & fibrous tissue |
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Sweating |
Excellent cooling mechanism that is controlled by autonomic nervous system |
Thermoregulation |
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Cooling |
Evaluation of water from soon which absorb body heat |
Thermoregulation |
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Arteriolar vasolidation |
Brings large quantity of blood to skin which accelerates the evaporation of sweat by maximizing heat energy available for liquid-gas phase exchange |
Maximum heat loss |
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Arrector pili |
Muscles contract, causing hair on skin to stand up on end (piloerection), helps v talk a layer of grated aid near skin |
Cold conditions |
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Shivering |
Requires a sizeable amount of ATP, however significant portion of energy from ATP is converted into thermal energy |
In cold conditions |
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Brown fat |
More common in infant, had much less efficient electron transport chain, meaning more heat energy is released as fuel is burned |
Cold temp |
