Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Principles of Animal PhysiologyIntroduction▪What is LIFE?▸LIFE ♦“Things” organized to use energy and raw materials from their environment, maintain their integrity and reproduce.Principles of Animal PhysiologyIntroduction▪What is PHYSIOLOGY?▸PHYSIOLOGY is FUNCTION!!!▸PHYSIOLOGY is an INTEGRATIVE science♦Uses Anatomy, Physics, Chemistry . . .▸SUBDISCIPLINES of Animal Physiology♦Comparative; Environmental; Evolutionary; Development; Cell ...Principles of Animal PhysiologyIntroduction▪Why study Animal Physiology?▸Curiosity - I just want to know.▸Applications - I want to profit from what I know.▸Insights - Now what do I do with what I know?▪Human Physiology share:-▸The same fundamental biological processes.▸A common set of laws of physics and chemistry.▸The same principles and mechanisms of genetics.▸A linked evolutionary history.▪August Krogh principle:▸For a large number of physiological problems, there will be some animal on which it can be most conveniently studied.Principles of Animal PhysiologyIntroduction▪A physician and medical researcher who understands physiology - both its potential contributions and limitations -is better equipped to make intelligent and perceptive decisions about the body.Principles of Animal PhysiologyIntroduction▪Physiological processes arise through evolution▸Natural selection - process by which traits that enhance a species survival are able to produce more surviving members than others not having those characteristics♦Mechanistic (proximate) explanation–How does it work? Process by which events occur.–Traditional core of the physiological sciences♦Evolutionary explanation–How did it evolve to be the way it is?♦Teleological approach–Why does it work? Purpose for the event/system.–Sometimes assumes that features are always logically evolvedPrinciples of Animal PhysiologyIntroduction▪The Hypotheticodeductive Method (Scientific Method)▸Science is a way of thinking.▸Science is a logical way to investigate the universe.♦Observation–And ask questions♦Experimentation♦Hypothesis–testable and falsifiable♦Control♦Data–Analysis♦Replication♦TheoryPrinciples of Animal PhysiologyUse of Animals in Research▪Animal Rights vs Animal Welfare▸Animal Welfare - have changed drastically over the years▸Physiologists accept certain moral responsibilities♦Animals are used only for worthwhile experiments♦All necessary steps are taken to minimize pain and distress♦All possible alternatives to the use of animals are considered▸Institutional Animal Care and Use Committee▸Animals rights - Animals have the same legal and moral rights as humans doPrinciples of Animal PhysiologyLevels of Organization▪To understand how the body functions and coordinates its activities, we will first examine its components.▪Organizational levels▪Know and define these levels up to the organismPrinciples of Animal PhysiologyLevels of Organization▪Basic cell functions include:♦Self-organization: Using resources from the environment to create the cell♦Self-regulation: Maintain self-integrity in the face of disturbances♦Self-support and movement: Having structrures that give specific form to the cell and to move materials within the cell or to move the cell itself♦Self-replication: Reproducing to carry on the species, and to repair damagePrinciples of Animal PhysiologyLevels of Organization▪Four primary tissue types:♦Muscular tissue - specialized for contraction and force generation–Skeletal, cardiac and smooth♦Nervous tissue - specialized for initiation and transmission of electrical impulses♦Epithelial tissue - specialized in the exchange of materials–Sheets and secretory glands♦Connective tissue - have relatively few cells dispersed within an abundance of extracellualar material that they secrete–Loose, tendons, bones, blood (hemolymph)Principles of Animal PhysiologyHomeostasis▪Most cells are NOT in contact with the external environment▪Most cells CANNOT function without other cells▪Most cells are in contact with the internal environment▪The internal environment consists of material outside the cell, but inside the body▪Define ExtraCellular Fluid (ECF)▪Define IntraCellular Fluid (ICF)▪Define InterStitial Fluid (ISF)Principles of Animal PhysiologyHomeostasis▪Components of the ExtraCellular Fluid (fig 1-5)Principles of Animal PhysiologyHomeostasis▪Cells can live and function only when they are bathed by ECF that is compatible with their survival▪The cell must obtain nutrients and discharge waste to the ECF▪Claude Bernard (1813-1878)▸Le milieu interieur▪Walter B. Canon (1871-1945)▸Coined the term HomeostasisPrinciples of Animal PhysiologyHomeostasis▪Homeostasis♦Maintenance of relatively stable conditions in the internal environment and in other body statesPrinciples of Animal PhysiologyHomeostasis▪Interdependent relationship of cells, body systems and homeostasis (Fig 1-6)Principles of Animal PhysiologyHomeostasis▪Factors affecting Homeostasis♦Amount of energy-rich molecule - fuel♦O2 & CO2 concentration - for chemical reactions♦Waste products - toxcicity♦pH - acid/base balance, enzymatic activity♦Water, salt & electrocytes - cell size♦Volume & pressure♦Temperature - narrow range♦Social parameters - social insects (termites)Principles of Animal PhysiologyHomeostasis▪Feedback-Control Systems♦Conformers - animal’s internal changes parallel the external conditions– e.g. starfish - salinity; annelid worms O2♦Regulators - animal defend a relatively constant state♦Avoiders - minimize internal variations by avoiding environmental disturbances–Some fish avoid temperature changes by changing location♦Enantiostasis (allostasis) - change in one physiological variable to conteract a change in another–Blue crabs - change blood pH to increase O2 binding when in brachish waterPrinciples of Animal PhysiologyHomeostasis▪Comparisons of negative feedback control systems (Fig 1-8)a -components of a basic feedback systemb - control of room temperaturec - control of mammalian body temperaturePrinciples of Animal PhysiologyHomeostasis▪Feedback effectors♦Antagonistic control: Opposes change in the variable–Temperature