MPP 3202: Elements of PhysiologyInstructorsGradingTextPhysiologyOrgan SystemsPhysiology: Course ThemesHomeostasisHomeostasis: Fluid CompartmentsMass BalanceHomeostasis: Steady State ≠ EquilibriumHomeostasis: ControlLocal vs. Reflex ControlFeedback LoopsNegative FeedbackSlide 16Positive FeedbackSlide 18Circadian RhythmMPP 3202: Elements of PhysiologyAlan [email protected]•Lecture–Block 1: Dr. Parrish•Exam: Friday 9/19–Block 2: Dr. Parrish•Exam: Wed 10/15–Block 3: Dr. Korthuis•Exam: Mon 11/10–Block 4: Dr. Kalogeris•Exam: Tue 12/17 (10-12)•Laboratory–Dr. MilanickGrading•Exams: Four multiple choice exams, 80 points each. Makeup exams will be essay format; 10 pt/day penalty for taking an exam late. •Homework: 10 assignments; 8 pts each.* Based on shortage of texts at bookstore, the homework #1 due date will be extended.•Laboratory: 100 points •Grading Scale is 90, 80, 70, 60Text•Human Physiology: An Integrated Approach•Access the online version/study resources via the Mastering A&P link on the MPP3202 Blackboard site; instructions to log in are posted on blackboard. You must have access to complete the homework assignments. •Course ID MAPPARRISH63840Physiology•Normal function of living organism–Components (structure)–Processes (function)•IntegrativeCHEMISTRYAtomsCells TissuesMolecules OrgansPHYSIOLOGYCELL BIOLOGYMOLECULAR BIOLOGYECOLOGYOrgansystemsOrganismsPopulations ofone speciesEcosystem ofdifferent speciesBiosphereOrgan SystemsIntegumentary systemCirculatory system Respiratory system Nervous system Endocrine system Digestive system Urinary system Reproductive system Musculo- skeletal systemPhysiology: Course Themes•Structure and Function•Energy storage, transfer and use•Information flow•Homeostasis; including organ integrationCompensation failsInternal changeresults in lossof homeostasisOrganism inhomeostasisOrganism attemptsto compensateExternalchangeInternalchangeCompensation succeedsWellnessIllness or diseaseHomeostasis•Bernard (~1860) “it is the constancy of the internal environment that is the condition for a free and independent life”•Cannon (1929)Recognized environmental factors (pH, osmolarity, temperature), materials (nutrients, water, electrolytes, oxygen), internal secretions (hormones, chemical signals) as variables of homeostatic control.Homeostasis: Fluid CompartmentsCells containintracellularfluid (ICF)Cells aresurrounded bythe extracellularfluid (ECF)The cellmembraneseparatescells fromthe ECFExternalenvironmentIntracellularfluid (ICF)Extracellular fluid (ECF)CellsECF1/3 2/3ICF = intracellular fluid (compartment)Fluid within cellsECF = extracellular fluidFluid outside cells but within bodyIs the “internal environment”SubdivisionsPlasma: fluid around blood cellsTissue fluid: fluid surrounding other cellsMass Balance•Homeostasis depends on body maintaining mass balance, i.e. for the amount of substance in the body to remain constant, any gain must be offset by an equal loss.•Total amount (“load”) = intake + production – excretion – metabolism•Clearance = the rate a which a compound disappears from blood.ECFICF14012010080604020K+Na+Cl-K+Na+Cl-Concentration (mmol/L)Homeostasis: Steady State ≠ EquilibriumInputsignalResponseOutputsignalIntegratingcenterHomeostasis: Control ReceptorsThermoreceptorsChemoreceptorsBaroreceptorsIntegrating centerOrchestrates an appropriate responseMany integrating centers are found in the brainEffectorsResponsible for body responsesMuscles (smooth, striated, and cardiac)GlandsSignalsInput signal is from a receptor to an integrating centerOutput signal is from an integrating center to an effectorChemical or nervesBrainevaluates the change and initiates a response.Systemicchange in blood pressure sensedhere.BrainLOCALCHANGELOCALRESPONSEBlood vesselsREFLEXRESPONSEis initiated by cellsat a distant site.In local control, cellsin the vicinity of thechange initiate theresponse.In reflex control, cells at a distantsite control theresponse.ResponseStimulusIntegrating centerKEYLocal vs. Reflex ControlTimeResponse loopturns onSetpoint of functionNormalrange offunctionNegative feedback turnsresponse loop offTemperature (C)2829303132Feedback LoopsResponseInitialstimulusStimulusResponse loopshuts offNegative feedback: the response counteractsthe stimulus, shutting off the response loop.Negative Feedback•Response opposes or removes the signal•Can restore normal state, but cannot prevent initial signalNegative FeedbackResponseInitialstimulusStimulusPositive feedback: the response reinforces the stimulus, sending the variable farther from the setpoint.Feedback cycleAn outside factor isrequired to shut offfeedback cycle.Positive Feedback•Response reinforces the stimulusPositive FeedbackCircadian
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