Chapter 13

Chapter 13 Cardiovascular SystemBasics of this systemOrgansHeartPumps 7k L/dayBlood VesselsArteriesAtriolesCapilariesVenulesVeinsTwo circuitsPulmonarySystemicWithout circulation, what would happen?

2Structure of HeartBasics- Heart is a muscular pump.LocationBetween 2nd and 5th intercostal spacePericardiumVisceral, ParietalWall of HeartEpi-,Myo-,Endo-Cardium

Usually about 14cm long, and 9cm highLayersPericardium- encloses heart and proximal ends of the large blood vesselsConsists of fibrous outsideMore delicate double layer contains visceral (epicardium) which is on the heart itself.This folds over on itself to create the parietal pericardium.The space created by this folding over is called the pericardial cavity contains serrous fliud.Wall of the heartEpicardium= visceral pericardiumMyocardium- muscles, lots of blood vessels, Endocardium- conetcive tissues, blood vessels, and purkinje fibers

3

Chambers and Valves

atria- walls are thinVentricles- thicker walls. Left thicker than rightSeptum- separates de-oxygenated blood from oxygenated blood- why is this good?ValvesAV (tricuspid)Mitral (bicuspid)PulmonaryAortic5Flow of BloodStarting at Right atriumTricuspid valveRight VentriclePulmonary ValvePulmonary ArteryLungsPulmonary VeinsLeft atriumBicuspid valveLeft VentricleAortic valveAorta

Chordae TendinaePapillary Muscles

6The cusps (flaps) of the bicuspid and tricuspid valves are anchored to the ventricle walls by fibrous cords called chordae tendineae, which attach to the wall by papillary muscles. This prevents the valves from being pushed up into the atria during ventricular systole.

Right Atrium Right Atrioventricular Valve (Tricuspid Valve) Right Ventricle Left Atrium Left Atrioventricular Valve (Mitral Valve) Left Ventricle Papillary Muscle Chordae Tendinae 9. Mitral Valve cusps

Cardiac ConductionSA NodeJunctional FibersAV NodeAV BundlePerkinje Fibers

Bruce Protocol

Heart Actions

Heart Actions

Can you identify these parts?Heart Actions

Heart ActionsDuring one complete heartbeatSystole- contraction of chamberDiastole- relaxation of a chamberCardiac cycleDifference in pressuresAtria Ventricle70% of blood moved by pressure aloneVentriclesArteriesDifference in pressureAtria fill as ventricles contract

Heart SoundsTwo part sound (use stethoscopes if available)Lubb-DuppLubb- ventricle contractionDupp- ventricle relaxation

ECGElectrocardiogramRecording of the electrical events during a cardiac cycleP WaveDepolarization of the atriaQRS ComplexDepolarization of ventriclesT WaveRepolarization of the ventricles

Interpreting ECGsAn ECG is printed on paper covered with a grid of squares.Notice that five small squares on the paper form a larger square. The width of a single small square on ECG paper represents 0.04 seconds. A common length of an ECG printout is 6 seconds; this is known as a "six second strip."

Analyze an ECG

Each one of the figures represents an ECG pattern displaying three types of abnormal rhythms: Tachycardia, Bradycardia, and Arrhymthmia. Identify each.Regulation of Cardiac CycleVolume of blood pumped changesExerciseControlled by Medulla OblangataParasympatheticImpulses decrease heart rateSympatheticIncrease heart rate and force of contractionsTemperatureBaroreceptors

Cardiac OutputCardiac Output

Stroke VolumeLVEDV-LVESV

Heart Rate

Q=SV x HR

Changes in HR, SV, COSNS

PNS

Venous Return

Exercise

Elite Athletes

Calcium

HR

BP

Arteries and Veins

Tunica Externa Tunica MediaTunica Interna

VasoconstrictionVasodilation

Capillaries

Blood PressurePressure is highest in arteries, why?SystolicDyastolicPulseRecoiling of the arterial wallsFactors Influencing BPStroke VolumeBlood discharged per contraction of ventriclesCardiac OutputSV x HRBlood volume5 liters in adultPeripheral ResistanceFriction between blood and blood vesselsViscosityFluid content

Cardioinhibitor ReflexCardioaccelerator Reflex