Recipient / Blood Group / Person 1 / Person 2 / Person 3 / Person 4 / Person 5
Person 1 / N/A
Person 2 / N/A
Person 3 / N/A
Person 4 / N/A
Person 5 / N/A
Cardiovascular System Handout
Blood Group Comparison Chart
Labelling Diagram
Blood Flow Through the Heart
Auscultation of the heart
Auscultation is that part of the physical examination involving the act of listening with a stethoscope to sounds made by the heart, lungs, and blood.
Normal Heart Sounds
Normal heart sounds are produced by closure of the valves of the heart.
Flow through the valves will affect the sound the valve makes. Thus, in situations of increased flow (exercise for example) the intensity of the heart sounds will be increased. In situations of low flow (shock for example) the intensity of the heart sounds will be decreased.
S1: The S1 sound is normally the first heart sound heard. (‘Lub’, in lub-dub). S1 corresponds to closure of the mitral and tricuspid valves. A normal S1 is low-pitched and of longer duration than S2.
S2: The S2 sound is normally the second sound heard. (‘Dub’ in lub-dub) S2 corresponds to closure of the pulmonary and aortic valves. A normal S2 is higher-pitched and of shorter duration than S1.
The flow from the ventricles is more forceful than the flow from the atria. Therefore, S2 will normally be the louder sound.
Abnormal heart sounds
Extra heart sounds
The rarer extra heart sounds form gallop rhythms and are heard in both normal and abnormal situations.
S3 = Rarely, there may be a third heart sound. It occurs just after S2 and is lower in pitch than S1 or S2 as it is not of valvular origin. The third heart sound is normal in youth and some trained athletes, but if it re-emerges later in life it may signal cardiac problems.
S4 = The rare fourth heart sound is sometimes audible in healthy children and again in trained athletes, but when audible in an adult is called a presystolic gallop or atrial gallop. This gallop is produced by the sound of blood being forced into a stiff/hypertrophic ventricle. It is a sign of a pathologic state, usually a failing left ventricle. The sound occurs just before S1.
Heart murmurs
Heart murmurs are produced as a result of turbulent flow of blood. They are usually heard as a whooshing sound. They can be caused by regurgitation through a valve, narrowing of a heart valve, or abnormal openings between the left ventricle and right heart.
Clicks and rubs
Clicks: These are short, high-pitched sounds. They are common in patients with a valve stenosis or prolapse.
The atrioventricular valves of patients with mitral stenosis may open with an opening snap on the beginning of diastole.
Patients with mitral valve prolapse may have a mid-systolic click along with a murmur.
Aortic and pulmonary stenosis may cause an ejection click immediately after S1.
Rubs: Patients with pericarditis, an inflammation of the sac surrounding the heart (pericardium), may have an audible pericardial friction rub. This is a characteristic scratching, creaking, high-pitched sound emanating from the rubbing of both layers of inflammated pericardium. It is very dependent on body position and breathing, and changes from hour to hour.
Where to listen
There are four major functional areas of auscultation of the heart. They are named for the valve that they best assess.
The bell of the stethoscope is best for listening to low pitched sounds such as murmurs
The diaphragm filters out low pitched sounds, so it is best for high pitched sounds such as the second heart sounds S2
Area / Location / AbnormalityAortic / 2nd Intercostal space
R sternal border / / Aortic Stenosis
Pulmonic / 2nd Iintercostal space
L sternal border / / Pulmonary stenosis or regurgitation
Tricuspid / L lower sternal border / / Tricuspid stenosis
Mitral / 5th Iintercostal space / / Mitral stenosis or regurgitation
Partner work
Working with a partner, listen to each other’s heart beat at the four locations in the table.
Experiment using both the bell and diaphragm of the stethoscope
Can you hear both S1 and S2?
Where is S1 loudest?
Where is S2 loudest?
Are there any extra heart sounds present?
If so what kind of sounds is it and how loud is it?
How to Take Blood Pressure
Blood pressure is the pressure exerted on the wall of the artery or vein as blood is pumped through the body. Blood does not flow readily, it surges along with each beat of the heart.
Systolic and Diastolic pressure
As blood is pumped through the body it exerts pressure on the veins and arteries. The systolic pressure is the pressure as the heart contracts and pumps the blood.
The diastolic pressure is the pressure in the vessels when the heart is at rest between beats.
Blood pressure is recorded as a fraction such as 110/70. The systolic pressure is the top number and the diastolic number is the bottom number.
Influencing Factors
Factors that can influence blood pressure readings include proper cuff size for the size of the arm, activity, emotions, posture, medications, alcohol consumption, temperature and diet.
How to take blood pressure
To take a blood pressure, the person should be sitting comfortably and relaxed. Sleeves are pushed up or the shirt removed to reveal a naked arm as clothing can interfere with the pressure of the inflated cuff as well as hearing the correct sounds.
The cuff of the sphygmomanometer is placed on the upper arm. It is centred over the brachial artery which is located in the crook of the elbow. The gauge should be placed so it can be easily read. There is usually a place on the cuff to clip it on. Once the cuff is secured, raise the arm to heart level, place your arm underneath it to support it and ask the person to relax their arm.
Palpate (feel for) the brachial pulse and place the diaphragm of the stethoscope over this spot. Place the ear pieces on the stethoscope into your ears. Listen to the brachial pulse.
Close the valve on the bladder of the cuff and begin to squeeze the bulb. Continue squeezing until the needle on the gauge reads at least 180 or until it is 10mmHg above where you last heard the as pulse as you inflated the cuff. Some people cannot hear this and so it is usually pumped up to 180-200mmHg on the gauge.
As the blood is pumped through the vessels a turbulence is heard. These sounds are created by turbulence as the blood begins to flow through the arteries after the blood pressure cuff has temporarily stopped the flow by the pressure exerted as it was inflated. When the sound is first heard, this is the systolic pressure; and when the sound ceases as the turbulence ends, the diastolic pressure is determined. We call these sounds Karotkoff sounds
Open the valve slowly and allow the cuff to deflate by 5mmHg/second while you listen to the artery. When you first hear the Karotkoff sound this is the systolic pressure. Continue deflating the cuff until you no longer hear the Karotkoff sound. This is the diastolic pressure.
At this point you can open the valve completely to allow the cuff to deflate rapidly. If you did not hear clearly, wait at least one minute before repeating the procedure.