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Jaymie TicknorIntro Nutrition Science 2460 Sect. 00222 June 2014Unit #3 : Chapters #7-9 Chapter #7:● Intracellular Fluid: the fluid held at any given time within the walls of the body’s cells○ 50-70% of a healthy adult’s body weight is fluid● Extracellular Fluid: the fluid outside the body’s cells, either in the body’s tissues or as the liquid portion of blood, called plasma1. Tissue Fluid: also called interstitial fluid; flows between the cells that make up a particular tissue or organ, such as muscle fibers or the liver2. Intravascular Fluid: found within blood and lymphatic vesselsa. Plasma is the fluid portion of blood that transports blood cells through blood vesselsi. Also contains proteins that are too large to leak out of blood vessels into surrounding tissue fluid● Solutes: dissolved substances/minerals that are critical for hydration and neuromuscular function1. Sodium (+)2. Potassium (+)3. Chloride (-)4. Phosphorus (-)5. Salts (sodium and chloride)● Electrolytes: a substance that dissociates in solution into positively and negatively charged ions and is thus capable of carrying an electrical current○ Sodium (+), potassium (+), chloride (-), and hydrogen phosphate (-)■ Sodium chloride = table salt● Also maintain extracellular fluid balance● Ions: any electrically charged particle, either positively or negatively charged● Solvent: a substance that is capable of mixing with and breaking apart a variety of compounds○ Water is a good solvent● Metabolic Water: the water formed as a by-product of our body’s metabolic reactions○ Breakdown of carbohydrates, fats, and proteins■ This water contributes about 10-14% of the water the body needs each day● Depolarization: stimuli prompt changes in membranes that allow an influx of sodium into the nerve cell, causing the cell to become slightly less negatively charged● Repolarization: the cell membrane returns to its normal electrical state through the release of potassium to the outside of the cell● Hypothalamus: command center for fluid management● Kidneys: removes excess sodium from the body and manages the water content of theblood● Blood Volume: the amount of fluid in blood● 2.7 liters needed for women, 3.7 liters needed for men● Calcium: flows in and out of muscle cells from the extracellular space○ Provides muscle contraction stimulus● Heat Stroke: a potentially fatal response to high temperature characterized by failure of the body’s heat-regulating mechanisms○ Commonly called sunstroke● Thirst Mechanism: a cluster of nerve cells in the hypothalamus that stimulate our conscious desire to drink fluids in response to:○ Increase in the concentration of salt in our blood, decrease in blood pressure and blood volume, or dryness in the tissues of the mouth and throat● Hypernatremia: a condition in which blood sodium levels are dangerously high● Hyponatremia: a condition in which blood sodium levels are dangerously low● Hyperkalemia: a condition in which blood potassium levels are dangerously high● Hypokalemia: a condition in which blood potassium levels are dangerously lowChapter #8:● Atoms: cannot be broken down by natural means● Particles: physicists learned how to split atoms into these components● Nucleus: the positively charged, central core of an atom○ It is made up of two types of particles - protons and neutrons - bound tightly together○ The nucleus of an atom contains essentially all of its atomic mass● Electron: a negatively charged particle orbiting the nucleus of an atom● Metabolism: the process by which our body breaks down and builds up molecules● Oxidation: a chemical reaction in which molecules of a substance are broken down into their component atoms○ During oxidation, the atoms involved lose electrons● Reduction: atoms that are capable gaining electrons during metabolism● Exchange Reaction: loss and gain of electrons typically results in an even exchange of electrons● Free Radical: a highly unstable atom with an unpaired electron in its outermost shell○ Formed during everyday body processes that produce energy● Antioxidants perform their role in stabilizing free radicals in three ways:1. Antioxidant vitamins work independently by donating their electrons or hydrogen atoms to free radicals to stabilize them and reduce the damage caused by oxidation2. Antioxidant minerals, including selenium, copper, iron, zinc, and manganese, act as cofactorsa. A mineral or other inorganic substance that is needed to allow enzymes to function properlyb. These minerals function within complex antioxidant enzyme systems that convert free radicals to less damaging substances that are excreted by our bodies3. Phytochemicals (beneficial plant chemicals) such as beta-carotene and other compounds help stabilize free radicals and prevent damage to cells and tissues● Vitamin A may act as an antioxidant by scavenging free radicals and protecting LDLs from oxidation● Keshan disease: a heart disorder caused by selenium deficiency○ It was first identified in children in the Keshan province of China● Kashin-Beck Disease: a disease of the cartilage that results in deforming arthritis○ Symptoms include impaired immune responses, infertility, depression, hostility, impaired cognitive function, and muscle pain and wasting● Provitamins: an inactive form of a vitamin that the body can convert to an active form○ Ex: beta-carotene■ Converts beta-carotene to the active form of vitamin A, retinol, thus beta-carotene is a precursor of retinol● Vitamin A is highly toxic and supplementing the diet with 3 times the RDA for vitamin Ais a toxinChapter #9:● Calcitonin: a hormone secreted by the thyroid gland when blood calcium levels are too high○ Inhibits the actions of vitamin D, preventing reabsorption of calcium in the kidneys, limiting calcium absorption in the small intestine, and inhibiting the osteoclasts from breaking down bone○ Inhibits absorption of calcium by the kidneys and intestine● Vitamin D is considered a hormone because it is made in one part of the body yet regulates various activities in other parts of the body○ Regulates calcium absorption and utilization● Phylloquinone: the primary dietary form of vitamin K and also formed found in plants● Menaquinone: animal form of vitamin K produced by bacteria in the large intestine● Prothrombin: a protein that plays a critical role in blood clotting●

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UNT HMGT 2460 - Unit #3 : Chapters #7-9

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