Outline. Integument System.docx - Skin | API Online Lecture...

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Skin|API Online LectureIntegument SystemIntroduction:Skin is the largest organ in the body and makes upapproximately 10 – 15% of our total body weight.Overview of the Integumentary SystemChunk 5.1Skin StructureThe skin, also known as thecutaneous membrane, has twomain components.The superficialepidermis(epi-= “on top,”derm- = “skin”)consists of keratinized stratified squamous epithelium that restson top of a basement membrane.The deepdermisconsists of loose connective tissue and dense irregular connectivetissue.Embedded in the epidermis and the dermis arethe skins’ accessory structures:hair, nails,sweat-producingsweat glands, and oil-producingsebaceous glands.The skin also hassensory neuronsand theirassociated receptors, such aslamellatedcorpuscles. In addition, there are also smallbands of smooth muscle calledarrector pilimusclesthat attach to hairs in the dermis.The epidermis is avascular (lacks a bloodsupply). Oxygen and nutrients diffuse from bloodvessels underneath in the dermis.Deep to the dermis is the hypodermis (hypo- =“below”), which is known as the superficial fasciaor subcutaneous tissue. The hypodermis is notpart of skin, but it anchors the skin to the muscleand bone deep to it. The subcutaneous layer alsocontains larger blood vessels which makes it agood place to give subcutaneous injections.1 |P a g e
Skin|API Online LectureFunctions of the Integumentary SystemProtectionProtection of underlying tissues from damage. Tissue damage comes from three mainsources: mechanical (physical) trauma, such as stretching, pressure, or abrasion;disease-causing microorganisms known aspathogens(path- = “disease”,-gen=“causing”); and environmental hazards, such as chemicals and radiation.Protection from mechanical traumaProtection from pathogensProtection from the environment2 |P a g e
Skin|API Online LectureThermoregulationThe body’s internal temperature is determined largely by the many reactions that arepart of its metabolism and muscle activity. Thermoregulation is maintenance of a stableinternal body temperature through negative feedback loops.Stimulus: Body temperature increases above normal range.Example:exercise, hot weatherReceptor: Thermoreceptors detect increase in temperature.Brain receptorscan detect internal fluid temperatureControl center: Thermoregulatory center in brain receives signals fromreceptors.The hypothalamus acts as the body’s “thermostat”.Effector/response: The control center stimulates effectors to respond withcooling mechanisms.Example, increase in sweat production, decrease orincrease in blood flow to the skin surface.Homeostasis and negative feedback: Body temperature returns to normalrange, and negative feedback stops cooling mechanisms.Thermoreceptorshelp return body temperature to normal.

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Term
Spring
Professor
N/A
Tags
Stratum Corneum, Skin anatomy

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