Presentation on theme: "Animal Physiology Zool 4230 General objectives:"— Presentation transcript:
1Animal PhysiologyZool 4230General objectives:1. Gain factual knowledge2. Learning fundamental principles, generalizations, or theories
2Physiology is the study of life processes: Study of physiologyPhysiology is the study of life processes:· How living systems work, from the molecularlevel to organ systems and to the whole organism· How the organism responds to physical activities and to the environment around it, whether it is the vacuum of space or the depths of the ocean· How disease can affect living systems· How the genome translates into function both within the cell and the whole organism
8Goal- to maintain life Need Nutrients Oxygen Water Survival needGoal- to maintain lifeNeedNutrientsOxygenWaterMaintain body temperatureAtmospheric pressue
9Figure 1.1 The study of physiology integrates knowledge at all levels of organization (Part 1) anphys-fig jpg
10Figure 1.1 The study of physiology integrates knowledge at all levels of organization (Part 2) anphys-fig jpg
11Physiology’s two central questions Origin– why do modern-day animals possess the mechanisms they have?Mechanism– how do modern-day animals carry out their functions?
12Why do modern-day animals possess the mechanism they have? The Study of OriginWhy do modern-day animals possess the mechanism they have?Products of evolutionThe study of evolutionary origins reveals the significance of mechanismsReliance on indirect reasoning– very rarely understood
13Key process of evolutionary origin Natural selection- increase in frequency of genes that produce phenotypes that improves an animal’s chances of survival and reproduction within the environmentAdaptations- aid the survival and reproductionAdaptive significance evolved by natural selection
14Figure 1.4 Structures similar in performance & adaptive significance can differ dramatically (Part 1)anphys-fig jpg
15Figure 1.4 Structures similar in performance & adaptive significance can differ dramatically (Part 2)anphys-fig jpg
16Fitness– link to adaptation Environment– habitat Natural selectionTwo basic conceptsFitness– link to adaptationEnvironment– habitatBiome: problems encounterDesign and strategyBehavioral modification
17Environmental components StressBiotic– direct and indirect effects of other organisms, e.g. competitionAbiotic– physical and chemicalMagnitude of fluctuationsLong term– tsunami outcomeShort term– lunar or daily cycleResource/energy availability
18Figure 1.9 Fish around Antarctica spend their entire lives at body temperatures near –1.9°C anphys-fig jpg
20Figure 1.11 A thermophilic (“heat-loving”) lizard common in North American deserts anphys-fig jpg
21AdaptationAdaptationTraits observed– result of selectionNatural selection adjusts the frequency of genes that code for traits affecting fitnessShort term compensatory changesAcclimationAcclimatization
22Responses to changes in environmental conditions AvoidanceConformityRegulationBehavior
23Conformity and regulation Two principal types of relations between an animal’s internal and external environmentConformity/regulationConformity- an animal permits internal and external conditions to be almost equalRegulation- an animal maintains internal constancy with external variability
24Figure 1.5 Conformity and regulation anphys-fig jpg
25Figure 1.6 Mixed conformity and regulation in a single species anphys-fig jpg
26Advantages and disadvantages of conformity and regulation Regulation- disadvantage– costs energyRegulation- advantage– permits cells to function independently of outside conditionConformity- disadvantage- cells within the body are subject to change when outside condition changesConformity- advantage– avoids energy costs of maintaining organization
27Responses to environmental change Acute responseChronic responseAcclimationAcclimatizationEvolutionary response
28Figure 1.7 Heat acclimation in humans as measured by exercise endurance anphys-fig jpg
33Protein synthesis and degradation Control of gene expressionIntracellular proteolytic mechanismsDegradation may occurIn cytoplasmIn endoplasamic reticulumUbiquitin (marker protein)serves as degradation signal
34Six steps at which gene expression can be controlled
36Interaction of two G proteins with a single cAMP-producing adenyl cyclase, giving both stimulatory and inhibitory pathways
37Extracellular control signals Growth factorHormonesNeurotransmitters
38Size and scalingBody-size relations are important in making prediction of the species’ physiological and morphological traits.Length, area, and volumeIsometric scalingAllometric scaling
39Figure 1.8 Length of gestation scales as a regular function of body size in mammals anphys-fig jpg
40Figure 1.18 Physiological variation among individuals of a species anphys-fig jpg
41Maintaining constancy of internal environment. HomeostasisMaintaining constancy of internal environment.Dynamic constancy.Within a certain normal range.Maintained by negative feedback loops.Regulatory mechanisms:Intrinsic:Within organ being regulated.Extrinsic:Outside of organ, such as nervous or hormonal systems.Negative feedback inhibition.
42Sensor: Integrating center: Effector: Feedback LoopsSensor:Detects deviation from set point.Integrating center:Determines the response.Effector:Produces the response.
43Reverses the deviation. Produces change in opposite direction. Negative FeedbackDefends the set point.Reverses the deviation.Produces change in opposite direction.Examples:Insulin decreases plasma [glucose].Thermostat.Body temperature.
45Action of effectors amplifies the changes. Positive FeedbackAction of effectors amplifies the changes.Is in same direction as change.Examples:Oxytocin (parturition).Voltage gated Na+ channels (depolarization).
46Confidence in rational ability, honesty and humility. Scientific MethodConfidence in rational ability, honesty and humility.Specific steps in scientific method:Formulate hypothesis:Observations.Testing the hypothesis:Quantitative measurements.Analyze results:Select valid statistical tests.Draw conclusion.