EXSS 276 1st Edition Lecture 2 Outline of Last Lecture I. Syllabus OverviewII. Intro to Human PhysiologyOutline of Current LectureI. HomeostasisII. GradientsIII. Feedback LoopsIV. The CellV. Key Terms in PhysiologyVI. MetabolismCurrent LectureI. Homeostasisa. Maintaining internal environment w/in physiological limitsb. Accomplished via feedback loopsc. Continually disrupted by external and internal stimuli i. Usually mild and temporaryII. Gradientsa. Concentration, electrical, temperature, pressureb. Difference in concentration of substance in one area of cell or tissue compared todifference in concentration of a substance in another area of cell or tissue c. Substances like to move down gradients from high to low III. Feedback loopsa. Maintain homeostasisb. Components: receptor, control center, effectorc. Negative Feedbacki. Response to stimulus reverses original stimulusii. Ex: blood pressureiii. Activity of effector produces result (drop in blood pressure) that opposes the stimulus (increase in blood pressure)d. Positive Feedbacki. Response that enhances original stimulusii. Ex: childbirth1. Oxytocin allows further stretching of cervixThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iii. Positive feedback system reinforces change in controlled conditionIV. The Cella. Cytoplasmi. Cytosol: mostly water and dissolved solutes/particlesii. Organelles: ER, mitochondria, lysosomesb. Membranei. Lipid bilayer, electrically chargedii. 3 lipids: cholesterol, glycolipids scattered among double row of phospholipid moleculesiii.iv. Flexible, sturdy barrier, surrounds and contains cytoplasm of cellv. Fluid mosaic modelvi. Proteins = gatekeepersvii. Lipids = barrierc. Nucleusi. Some red blood cells have none, other have several; most have oneii. DNAiii. Houses hereditary units called genes, which are arranged in single file along chromosomes (23 sets)d. Organellesi. Mitochondria1. Vesicle filled w/ fluid surrounded by double thick membrane2. Self replicating3. Main role in cellular respiration, oxidation of foodstuffs to produceATP4. Difference number in each tissueii. Lysosomes1. Irregularly shaped2. Contain enzymes to breakdown proteins, RNA, DNA, certain carbs3. Membrane may rupture; cortisone stabilizes itiii. ER1. Transports substances, stores newly synthesized molecules, synthesizes and packages molecules, detoxifies chemicals, releases calcium ions involved in muscle contraction2. Rough ER-outer surface studded w/ ribosomes; protein synthesis3. Smooth ER-does not contain ribosomes4. Ribosomes: sites of protein synthesis; composed by packages of ribosomal RNAiv. Golgi Apparatus1. Flattened sacs surrounding one pole of nucleus2. Abundant in secretory cells3. Modify proteins made by ER4. Process, sort, and package proteins to be transported to where needed V. Key Terms in Physiology – learn on your ownVI. Metabolisma. What is metabolism? Sum of all chemical reactions in the bodyi. Minimum amount of energy needed in 1 day = resting metabolic rateb. Processes depend on production of energyc. Carbohydratesi. Monosaccharide: glucose, fructose, galactoseii. Disaccharides: sucrose, lactose, maltoseiii. Glycogen: main polysaccharided. Catabolism: breakdown, exergonic, “lysis” e. Anabolism: building, endergonic, “genesis”f. Enzymes: regulate reaction speedi. Lower activation
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