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 2nd and 5th 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
Heart Actions
Can you identify these parts?
Heart Actions
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
 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