Cardiovascular Physiology Lab Flashcards
Auscultation of the hearts means
to listen to and study the various sounds arising from the heart during its pumping activity
The vibrations producing the sounds can be visually displayed through the use of a heart sound microphone and physiological recorder to produce a
phonocardiogram
1st Heart Sound
Produced at the beginning of systole when the atrioventricular (AV) valves close and the semilunar (SL) valves open. This has a lower pitched tone commonly termed the “lub” sound of the heartbeat
2nd Heart Sound
Occurs during the end of systole and is produced by the closure of the SL valves, the opening of the AV valves, and the resulting vibrations in the arteries and ventricles. Due to the higher blood pressures in the arteries the sound produced is higher pitched. It is commonly referred to as the “dub” sound
3rd Heart Sound
Occurs during the rapid filling of the ventricles after the AV valves open and is probably produced by vibrations of the ventricular walls
4th Heart Sound
Occurs at the time of atrial contraction and is probably due to the accelerated rush of blood into the ventricles
The 4 Major Auscultatory Areas
Aortic Area (aortic SL valve) Tricuspid Area (right AV valve) Pulmonary Area (pulmonary SL valve) Mitral Area (left AV valve)
Blood Pressure
the pressure exerted by the blood against the vessel walls
Where do we most commonly measure blood pressure?
arterial blood pressure
Systolic Blood Pressure
the highest pressure in the artery–produced during the heart’s contraction (systolic) phase
Normal systolic blood pressure for a 20-year old male is
120mm Hg
Diastolic Blood Pressure
the lowest pressure in the artery–produced during the heart’s relaxation (diastolic) phase
Normal diastolic blood pressure for a 20-year old male is
80mm Hg
Pulse Pressure
the difference between the systolic and diastolic pressures
Normal value for pulse pressure is
40mm Hg
Mean Blood Pressure
Diastolic Pressure + 1/3 of the pulse pressure. This is the average effective pressure forcing blood through the circulatory system
Normal value for mean blood pressure is
96-100mm Hg
Formula for Mean BP (mm Hg)
Cardiac Output (ml/min) X Total Peripheral Resistance (TPR units)