Cardiovascular System

Basics of this system Organs Heart Pumps 7k L/day Blood Vessels Arteries  Atrioles  Capilaries  Venules  Veins Two circuits Pulmonary Systemic Without circulation, what would happen?

Structure of Heart Basics- Heart is a muscular pump. Location Between 2 nd and 5 th intercostal space Pericardium Visceral, Parietal Wall of Heart Epi-,Myo-,Endo- Cardium

Chambers and Valves

Flow of Blood Starting at Right atrium… Tricuspid valve Right Ventricle Pulmonary Valve Pulmonary Artery Lungs Pulmonary Veins Left atrium Bicuspid valve Left Ventricle Aortic valve Aorta

The 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.

1.Right Atrium 2.Right Atrioventricular Valve (Tricuspid Valve) 3.Right Ventricle 4.Left Atrium 5.Left Atrioventricular Valve (Mitral Valve) 6.Left Ventricle 7.Papillary Muscle 8.Chordae Tendinae 9. Mitral Valve cusps

Cardiac Conduction SA Node Junctional Fibers AV Node AV Bundle Perkinje Fibers

Bruce Protocol

Heart Actions

Can you identify these parts?

Heart Actions

During one complete heartbeat Systole- contraction of chamber Diastole- relaxation of a chamber Cardiac cycle Difference in pressures Atria  Ventricle 70% of blood moved by pressure alone Ventricles  Arteries Difference in pressure Atria fill as ventricles contract

Heart Sounds Two part sound (use stethoscopes if available) Lubb-Dupp Lubb- ventricle contraction Dupp- ventricle relaxation

ECG Electrocardiogram Recording of the electrical events during a cardiac cycle P Wave Depolarization of the atria QRS Complex Depolarization of ventricles T Wave Repolarization of the ventricles

Interpreting ECGs An 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 Cycle Volume of blood pumped changes Exercise Controlled by Medulla Oblangata Parasympathetic Impulses decrease heart rate Sympathetic Increase heart rate and force of contractions Temperature Baroreceptors

Cardiac Output Stroke Volume LVEDV-LVESV Heart Rate Q=SV x HR

Changes in HR, SV, CO SNS PNS Venous Return Exercise Elite Athletes Calcium HR BP

Arteries and Veins

Tunica Externa Tunica Media Tunica Interna Vasoconstriction Vasodilation

Capillaries

Blood Pressure Pressure is highest in arteries, why? Systolic Dyastolic Pulse Recoiling of the arterial walls

Factors Influencing BP Stroke Volume Blood discharged per contraction of ventricles Cardiac Output SV x HR Blood volume 5 liters in adult Peripheral Resistance Friction between blood and blood vessels Viscosity Fluid content

Cardioinhibitor Reflex Cardioaccelerator Reflex