USMLE Step 1 Physiology Notes KAPLAN medical "USMLE Is a joint program of the Federat on of state Medicai Boards of the United Sates, Ine and the Nationa Board of Medleal Examiners
~- =-- ~ USMLE'Step 1 Physiology Notes KAPLA~. meulcaI *USMLEis a joint program of the Federation of State Medical Boards of the United States, Inc. and the National Board of Medical Examiners
Author and Executive edite Robert B. Dunn, Ph D Adjunct Associate Profess Loyola University Medical Center 几L Contributors Director of medical Illustration Susan Demesquita, Ph. D Christine shaa Professor, Department of Physiology Marshall School of medicine Director of Publishing and Media Huntington, Stanley S Passo, Ph. D Associate Professor, Department of physiolo Medical Illustrators New York Medical College Rich La Rocco and Christine Schaar valhalla, ny Production editors James Porter, Ph. D University of louisville e rofessor, Department of Kathlyn McGreevy Ruthie Nussbaum Production artist Kenneth H. Ibsen, Ph D Michael Wolff Director of Academic Development professor i University of Californi Joanna mylo Irvine, CA Cover Art Mary Ruebush, Ph. D Rich larocco Adjunct Professor of Microbiolog Montana State University
>', "I ~ Authorand ExecutiveEditor Robert B.Dunn, Ph.D. Adjunct Associate Professor Department of Medicine Loyola University Medical Center Chicago, IL Contributors Susan DeMesquita, Ph.D. Professor, Department of Physiology Marshall School of Medicine Huntington, WV Directorof MedicalIllustration ChristineSchaar Directorof PublishingandMedia Michelle Covello Stanley S. Passo, Ph.D. Associate Professor, Department of Physiology New York Medical College Valhalla, NY MedicalIllustrators Rich LaRocco and Christine Schaar James Porter, Ph.D. Professor, Department of Physiology University of Louisville Louisville, KY ProductionEditors Kathlyn McGreevy Ruthie Nussbaum Kenneth H. Ibsen, Ph.D. Director of Academic Development Kaplan Medical Professor Emeritus Biochemistry University of California Irvine, CA ProductionArtist Michael Wolff CoverDesign Joanna Myllo Mary Ruebush, Ph.D. Adjunct Professor of Microbiology Montana State University Bozeman, MT CoverArt Rich LaRocco - - - f
Table of contents Preface Section 1: General Topics Chapter 1: Membrane Transport Chapter 2: Body Compartments Section II: Excitable tissue Chapter 1: lonic Equilibrium and Resting Membrane potential 35 Chapter 2: The Neuron Action Potential Chapter 3: Synaptic Transmission Section II: Peripheral Circulation Chapter 1: General Aspects of the Cardiovascular System 75 Chapter 2: Regulation of Blood Flow Section IV: Skeletal Muscle Chapter 1: Excitation-Contraction Coupling 135 Chapter 2: Skeletal Muscle Mechanics 143 Section v: Cardiac Muscle Chapter 1: Electrical Activity of the Heart Chapter 2: Heart Muscle Mechanics medical
~ Tableof Contents Preface.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Section I: General Topics Chapter 1:MembraneTransport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Chapter2: BodyCompartments.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Section II: Excitable Tissue Chapter1:IonicEquilibriumandRestingMembranePotential.. . . . . . . . . . 35 Chapter2: TheNeuronActionPotential.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Chapter3: SynapticTransmission.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 SectionIII: Peripheral Circulation Chapter 1: GeneralAspectsof the CardiovascularSystem. . . . . . . . . . . . . . . 75 Chapter2: Regulationof BloodFlow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 SectionIV:Skeletal Muscle Chapter 1:Excitation-ContractionCoupling. . . . . . . . . . . . . . . . . . . . . . . . . 135 Chapter 2: SkeletalMuscleMechanics.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Section V:Cardiac Muscle Chapter 1:ElectricalActivityoftheHeart. . . . .. . . . . . .. . . . . . .. . . . . . . . 167 Chapter2: HeartMuscleMechanics.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 meClical v
Section VI: Respiration Chapter 1: Lung Mechanics...,,,.....,.. Chapter 2: Alveolar-Blood Gas Exchange 255 Chapter 3: Transport of o, and CO and the Regulation of Respiration Chapter 4: Four Causes of Hypoxemia Section VII: Renal Physiology Chapter 1: Renal Processes 303 Chapter 2: Clearance Chapter 3: Regional Transport .............. 325 Section VIll: Acid-Base Disturbances ion IX: Endocrinology Chapter 1: Mechanisms of Hormone Action 375 Chapter 2: The Hypothalamic-Anterior Pituitary System Chapter 3: Adrenal Hormones.,...... Chapter 4: Antidiuretic Hormone(ADH)and Regulation of Osmolarity and Extracellular Fluid(ECF) 405 Chapter 5: The Endocrine Pancreas Chapter 6: Growth Hormone Chapter 7: Adrenal Medulla 429 Chapter 8: Hormonal Control of Calcium and Phosphate Chapter 9: Thyroid Hormones Chapter 10: Male Reproductive System 457 Chapter 11: Female Reproductive System 467 Section X: Gastrointestinal Physiology vi medical
? SectionVI: Respiration Chapter 1: Lung Mechanics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 Chapter 2: Alveolar-Blood GasExchange.. . . . . . . . . . . . . . . . . . . . . . . . . . 255 Chapter 3: Transport of °2 and CO2 and the Regulation of Respiration. . . . . . . . . . . . . . . . . . . . . . . . 261 Chapter 4: Four Causes of Hypoxemia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 Section VII: Renal Physiology Chapter 1: Renal Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Chapter 2: Clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Chapter 3: RegionalTransport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Section VIII: Acid-Base Disturbances. . . . . ,.. ..,. 359 Section IX: Endocrinology Chapter 1: Mechanismsof HormoneAction. . . . . . . . . . . . . . . . . . . . . . . . . 375 Chapter 2: The Hypothalamic-AnteriorPituitarySystem. . . . . . . . . . . . . . . 379 Chapter 3: Adrenal Hormones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 Chapter 4: AntidiureticHormone(ADH) and Regulation of OsmolarityandExtracellularFluid(ECF) 405 Chapter 5: The Endocrine Pancreas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .411 Chapter 6: Growth Hormone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 Chapter 7: Adrenal Medulla. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 Chapter 8: HormonalControlof Calciumand Phosphate. . . . . . . . . . . . . . 433 Chapter 9: Thyroid Hormones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443 Chapter 10: Male ReproductiveSystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 Chapter 11: Female Reproductive System. . . . . . . . . . . . . . . . . . . . . . . . . . 467 Section X: Gastrointestinal Physiology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 vi KAPLAN d ' . me Ica I
Preface These seven volumes of Lecture Notes represent a yearlong effort on the part of the Kaplan Medical faculty to update our curriculum to reflect the most-likely-to-be-tested material on the current USMLE Step I exam. Please note that these are Lecture Notes, not review books. The Notes were designed to be accompanied by faculty lectures-ive, on video, or on the web Reading these Notes without accessing the accompanying lectures is not an effective way to review for the usmle To maximize the effectiveness of these Notes, annotate them as you listen to lectures. To facil itate this process, we've created wide, blank margins. While these margins are occasionally punctuated by faculty high-yield"margin notes, "they are, for the most part, left blank for your notations Many students find that previewing the Notes prior to the lecture is a very effective way to pre- pare for class. This allows you to anticipate the areas where you'll need to pay particular atten tion. It also affords you the opportunity to map out how the information is going to be pre- sented and what sort of study aids(charts, diagrams, etc. )you might want to add. This strate- gy works regardless of whether you're attending a live lecture or watching one on video or the Finally, we want to hear what you think. What do you like about the notes? What do you think couldbeimprovedPleaseshareyourfeedbackbyE-mailingusatmedfeedback@kaplan.com. Thank you for joining Kaplan Medical, and best of luck on your Step I exam! Kaplan Medical medicaⅶi
..... ~ Preface These seven volumes of Lecture Notes represent a yearlong effort on the part of the Kaplan Medical faculty to update our curriculum to reflect the most-likely-to-be-tested material on the current USMLE Step 1 exam. Please note that these are Lecture Notes, not review books. The Notes were designed to be accompanied by faculty lectures-live, on video, or on the web. Reading these Notes without accessing the accompanying lectures is not an effective way to review for the USMLE. To maximize the effectiveness of these Notes, annotate them as you listen to lectures. To facilitate this process, we've created wide, blank margins. While these margins are occasionally punctuated by faculty high-yield "margin notes;' they are, for the most part, left blank for your notations. Many students find that previewing the Notes prior to the lecture is a very effectiveway to prepare for class. This allows you to anticipate the areas where you'll need to pay particular attention. It also affords you the opportunity to map out how the information is going to be presented and what sort of study aids (charts, diagrams, etc.) you might want to add. This strategy works regardless of whether you're attending a live lecture or watching one on video or the web. Finally,we want to hear what you think. What do you like about the notes? What do you think could be improved? Please share your feedback by E-mailingusatmedfeedback@kaplan.com. Thank you for joining Kaplan Medical, and best of luck on your Step 1 exam! Kaplan Medical KAPLAN ii . . me IcaI vii /