What are the overall functions of the What are the overall functions of the cardiovascular system? What cardiovascular system? What

structures comprise the system?structures comprise the system?

QODQOD

Chapter 13Chapter 13

Cardiovascular SystemCardiovascular System

I. IntroductionI. Introduction

StructuresStructures– HeartHeart– ArteriesArteries

ArteriolesArterioles

– CapillariesCapillaries– VeinsVeins

VenulesVenules CircuitsCircuits

– Pulmonary circuitPulmonary circuit– Systemic CircuitSystemic Circuit– Coronary CircuitCoronary Circuit

13.2: Structure of the Heart13.2: Structure of the Heart

CoveringsCoverings– Visceral pericardiumVisceral pericardium– Parietal pericardiumParietal pericardium– Pericardial cavity – serous fluidPericardial cavity – serous fluid

Wall of the heartWall of the heart– EpicardiumEpicardium– MyocardiumMyocardium– EndocardiumEndocardium

Purkinje fibersPurkinje fibers

How is the heart’s structure How is the heart’s structure related to it’s function?related to it’s function?

QODQOD

Heart chambers and valvesHeart chambers and valves

Atria (Atrium)Atria (Atrium) VentriclesVentricles SeptumSeptum ValvesValves

– Tricuspid Tricuspid – Bicuspid (Mitral)Bicuspid (Mitral)– AorticAortic– PulmonaryPulmonary– Chordae tendinaeChordae tendinae– Papillary musclesPapillary muscles

Blood Vessels to and from HeartBlood Vessels to and from Heart

Superior and Inferior Vena cavaeSuperior and Inferior Vena cavae Cardiac veinsCardiac veins

– Coronary sinusCoronary sinus Pulmonary arteriesPulmonary arteries Pulmonary veinsPulmonary veins AortaAorta Coronary arteriesCoronary arteries

Pathway of BloodPathway of Blood

How does the heart make sure to How does the heart make sure to pump rhythmically and as a unit?pump rhythmically and as a unit?

QODQOD

13.3 Heart Actions13.3 Heart ActionsThe Cardiac CycleThe Cardiac Cycle

The HeartbeatThe Heartbeat– Atrial Atrial systolesystole and ventricular and ventricular diastole diastole– Atrial Atrial diastolediastole and ventricular and ventricular systolesystole– A-V valves open/closeA-V valves open/close

Due to changes in pressureDue to changes in pressure

Cardiac CycleCardiac Cycle

Heart soundsHeart sounds– ““Lubb” – ventricular contractionLubb” – ventricular contraction– ““Dupp” – ventricular relaxationDupp” – ventricular relaxation

Cardiac Muscle FibersCardiac Muscle Fibers– Fibers connect in branching systemFibers connect in branching system– Functional syncytiumFunctional syncytium

In atrial wallsIn atrial walls In ventricular wallsIn ventricular walls

Cardiac Conduction SystemCardiac Conduction System

S-A nodeS-A node– Located in right atriumLocated in right atrium– Self-initiate impulses that stimulate Self-initiate impulses that stimulate

cardiac muscle fibers to contractcardiac muscle fibers to contract– Rhythmic - Rhythmic - PacemakerPacemaker

A-V nodeA-V node– Located in interatrial septum (inferior)Located in interatrial septum (inferior)– Impulse is delayedImpulse is delayed– A-V bundle A-V bundle Purkinje fibers Purkinje fibers cardiac cardiac

muscle fibersmuscle fibers

Fig. 13.11Fig. 13.11

Fig. 13.12Fig. 13.12

ElectrocardiogramElectrocardiogram

Waves of ECGWaves of ECG– P waveP wave– QRS complexQRS complex– T waveT wave

Uses:Uses:– Assessment of heart’s conduction of Assessment of heart’s conduction of

impulsesimpulses– P-Q intervalP-Q interval

Fig. 13.14aFig. 13.14a

Regulation of Cardiac CycleRegulation of Cardiac Cycle

Medulla oblongataMedulla oblongata Parasympathetic nerve fibersParasympathetic nerve fibers Sympathetic nerve fibersSympathetic nerve fibers HypothalamusHypothalamus Temperature changeTemperature change IonsIons

– Potassium ionsPotassium ions Hyperkalemia/HypokalemiaHyperkalemia/Hypokalemia

– Calcium ionsCalcium ionsHypercalcemia/HypocalcemiaHypercalcemia/Hypocalcemia

Sympatheticnerve

Sympathetic trunk

Autonomic nerve impulses

Slide number: 1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Cerebrum(coronalsection)

Medulla(transversesection)

Spinal cord(transverse sections)

Hypothalamus

Cardiaccenter

Parasympatheticvagus nerve

S-A nodeA-V node

Sensoryfibers

Carotidsinus

Carotidbaroreceptors

Commoncarotid artery

Aorta

Aorticbaroreceptors

What is atherosclerosis? What is atherosclerosis? Causes? Signs/symptoms? Causes? Signs/symptoms?

Treatments?Treatments?

QODQOD

13.4 Blood Vessels13.4 Blood Vessels

ArteriesArteries– Strong, elastic, under high pressureStrong, elastic, under high pressure– 3 layers3 layers

Tunica internaTunica internaTunica mediaTunica mediaTunica externaTunica externa

ArteriolesArterioles– SmallerSmaller– Get thinner as they get closer to…Get thinner as they get closer to…

CapillariesCapillaries

Gas/nutrient exhchangeGas/nutrient exhchange– OpeningsOpenings– Semi-permeableSemi-permeable– Concentration gradientConcentration gradient– Filtration and hydrostatic pressureFiltration and hydrostatic pressure– Osmotic pressureOsmotic pressure

Smooth muscle – regulates blood Smooth muscle – regulates blood distributiondistribution

Water and other substances leave capillaries because of a net outward filtration pressure

Slide number: 2

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Capillary

Tissuecells

Lymphaticcapillary

Bloodflow fromarteriole

Water and other substances leave capillaries because of a net outward filtration pressure

Slide number: 3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Capillary

Tissuecells

Lymphaticcapillary

Bloodflow fromarteriole

Outward force,including hydrostaticpressure 41.3 mm Hg

Inward forceof osmoticpressure28 mm Hg

Net outward pressure13.3 mm Hg

Outward force, includinghydrostatic pressure

Net outward pressure

Inward force of osmoticpressure

= 41.3 mm Hg

= 13.3 mm Hg

= 28 mm Hg

Net force at arteriolar end

Water and other substances leave capillaries because of a net outward filtration pressure

Slide number: 4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Capillary

Tissuecells

Lymphaticcapillary

Bloodflow fromarteriole

Outward force,including hydrostaticpressure 41.3 mm Hg

Inward forceof osmoticpressure28 mm Hg

Net outward pressure13.3 mm Hg Outward force, including

hydrostatic pressure21.3 mm Hg

Inward force ofosmotic pressure28 mm Hg Net inward

pressure6.7 mm Hg

Outward force, includinghydrostatic pressure

Net outward pressure

Inward force of osmoticpressure

= 41.3 mm Hg

= 13.3 mm Hg

= 28 mm Hg

Net force at arteriolar end

Outward force, includinghydrostatic pressure

Net inward pressure

Inward force of osmoticpressure

= 21.3 mm Hg

= 6.7 mm Hg

= 28 mm Hg

Net force at venular end

Water and other substances leave capillaries because of a net outward filtration pressure

Slide number: 5

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Capillary

Tissuecells

Lymphaticcapillary

Bloodflow tovenule

Bloodflow fromarteriole

Outward force,including hydrostaticpressure 41.3 mm Hg

Inward forceof osmoticpressure28 mm Hg

Net outward pressure13.3 mm Hg Outward force, including

hydrostatic pressure21.3 mm Hg

Inward force ofosmotic pressure28 mm Hg Net inward

pressure6.7 mm Hg

Outward force, includinghydrostatic pressure

Net outward pressure

Inward force of osmoticpressure

= 41.3 mm Hg

= 13.3 mm Hg

= 28 mm Hg

Net force at arteriolar end

Outward force, includinghydrostatic pressure

Net inward pressure

Inward force of osmoticpressure

= 21.3 mm Hg

= 6.7 mm Hg

= 28 mm Hg

Net force at venular end

VeinsVeins

VenulesVenules VeinsVeins

– Thinner than arteriesThinner than arteries– Less smooth muscleLess smooth muscle– ValvesValves– Act as blood reservoirsAct as blood reservoirs

How is blood pressure regulated?How is blood pressure regulated?

QODQOD

13.5: Blood Pressure13.5: Blood Pressure

Arterial blood Arterial blood pressure:pressure:– Systolic pressureSystolic pressure– Diastolic pressureDiastolic pressure– PulsePulse

Factors Influencing Blood PressureFactors Influencing Blood Pressure

Heart actionHeart action– Stroke volumeStroke volume– Cardiac output = heart rate x stroke Cardiac output = heart rate x stroke

volumevolume Blood volumeBlood volume Peripheral resistancePeripheral resistance

– Vasoconstriction/VasidilationVasoconstriction/Vasidilation Blood viscosityBlood viscosity

– ResistanceResistance

Control of Blood PressureControl of Blood Pressure

Regulation of cardiac outputRegulation of cardiac output– BaroreceptorsBaroreceptors– Medulla oblongata (cardiac center)Medulla oblongata (cardiac center)– KidneysKidneys– Exercise, body temp, fear/angerExercise, body temp, fear/anger

Regulation of peripheral resistanceRegulation of peripheral resistance– Vasomotor centerVasomotor center

Venous Blood FlowVenous Blood Flow

Lower blood pressureLower blood pressure Skeletal muscle contractionsSkeletal muscle contractions VasoconstrictionVasoconstriction