Cardiovascular physiology lab

Question 1

First heart sound

Answer 1

Produced at the beginning of systole when the atrioventricular (A-V) valves close and the semilunar (S-L) valves open. This has a lower pitched tone, called the “lub” sound of the heartbeat

Question 2

Second heart sound

Answer 2

Occurs during the end of systole and is produced by the closure of the S-L valves, the opening of the A-V 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

Question 3

Third heart sound

Answer 3

Occurs during the rapid filling of the ventricles after the A-V valves open and is probably produced by vibrations of the ventricular walls

Question 4

Fourth heart sound

Answer 4

Occurs at the time of atrial contraction and is probably due to the accelerated rush of blood into the ventricles

Question 5

Auscultation

Answer 5

To listen to. In this case, we are listening to the heart and studying the sounds of the heart from vibrations produced when the heart valves close and the blood rebounds against the ventricular walls or blood vessels

Question 6

Stethoscope

Answer 6

Instrument used to listen to heart sounds

Question 7

Phonocardiogram

Answer 7

The vibrations producing the heart sounds can be visually displayed through the use of a heart sound microphone and physiological recorder to produce a phonocardiogram

Question 8

Auscultatory areas

Answer 8

The 4 areas on the chest where the sounds from each valve can be heard most clearly. 2 are on either side of the sternum at the level of the third rib, one is on the left side of the sternum at the level of the sixth rib, and the fourth is at about the same level but more lateral.

Question 9

Blood pressure

Answer 9

The pressure exerted by the blood against the vessel walls, the arterial blood pressure being the most frequently measured pressure and the most useful. It provides us with information on the heart’s pumping efficiency and the condition of the systemic blood vessels

Question 10

Systolic blood pressure

Answer 10

The highest pressure in the artery- produced during the heart’s contraction (systolic) phase. Normal for a 20-year-old male is 120mm Hg. Systolic blood pressure indicates the force of contraction of the heart.

Question 11

Diastolic blood pressure

Answer 11

The lowest pressure in the artery- produced during the heart’s relaxation (diastolic) phase. Normal for a 20-year-old male is 80mm Hg. The diastolic blood pressure indicates the condition of the systemic blood vessels (for instance, an increase in the diastolic pressure indicates a decrease in vessel elasticity)

Question 12

Pulse pressure

Answer 12

The difference between the systolic and diastolic pressures. Normal value is 40mm Hg.

Question 13

Mean blood pressure

Answer 13

Diastolic pressure + 1/3 of the pulse pressure. This is the average effective pressure forcing blood through the circulatory system. Normal value is 96-100mm Hg. The mean blood pressure is a function of two factors–cardiac output (C.O.) and total peripheral resistance (TPR)

Question 14

Mean blood pressure equation

Answer 14

Cardiac output times total peripheral resistance. Cardiac output equals heart rate times stroke volume

Question 15

Peripheral resistance depends on (2)

Answer 15

The diameter of the blood vessels and the viscosity of blood

Question 16

Direct method of measuring blood pressure

Answer 16

A cannula is inserted into the artery and the direct, head-on pressure of the blood is measured with a transducer or mercury manometer.

Question 17

Indirect method of measuring blood pressure

Answer 17

Pressure is applied externally to the artery and the pressure is determined by listening to arterial sounds (using a stethoscope) below the point where the pressure is applied. This is also called the auscultatory method. The auscultatory method has been found to be fairly close to the direct method in the pressures recorded; usually the systolic pressure is about 3-4 mm lower than that obtained with the direct method

Question 18

Palpatory method of measuring blood pressure

Answer 18

Older and less accurate. You palpate (feel) the pulse as pressure is applied to the artery. The systolic pressure recorded with the palpatory method is usually around 5mm Hg lower than that obtained using the auscultatory method.

Question 19

Sphygmomanometer

Answer 19

An instrument that applies pressure to the artery in the indirect blood pressure measurement methods. It consists of an inflatable rubber bag (cuff), a rubber bulb for introducing air into the cuff, and a mercury or anaeroid manometer for measuring the pressure in the cuff.

Question 20

Where is blood pressure measured?

Answer 20

The brachial artery of the upper arm. In addition to being a convenient position for taking measurements, it has the added advantage of being approximately the same level as the heart so that the pressures obtained closely approximate the pressure in the aorta leaving the heart. This allows us to correlate B.P. with heart activity.

Question 21

What is a major disadvantage of the palpatory method?

Answer 21

It can’t be used to measure diastolic pressure

Question 22

Korotkow sounds

Answer 22

The 4 phases of sound changes when measuring blood pressure using the auscultatory method

Question 23

Phase 1 of korotkow sounds

Answer 23

Appearance of a fairly sharp thudding sound which increases in intensity during the next 10mm Hg of pressure drop. The pressure when the sound first appears is the
systolic pressure.

Question 24

Phase 2 of korotkow sounds

Answer 24

The sounds become a softer murmur during the next 10-15 mm Hg drop in pressure.

Question 25

Phase 3 of korotkow sounds

Answer 25

The sounds become louder again and have a sharper thudding quality during the next 10-15 mm Hg of pressure drop

Question 26

Phase 4 of korotkow sounds

Answer 26

The sounds suddenly become muffled and reduced in intensity. The pressure at this point is termed the diastolic pressure. Thus muffled sound continues for another 5 mm Hg pressure drop, after which all sound disappears. The point where the sound ceases completely is
called the end diastolic pressure.

Question 27

Blood pressure varies with a person’s (3)

Answer 27

Age, weight, and sex

Question 28

How does blood pressure vary with age and sex?

Answer 28

Below the age of 35 women generally have a B.P. 10 mm Hg lower than that for men. However, after 40-45 years of age, a woman’s B.P. increases faster than does a man’s. The old rule of thumb of 100 plus your age is still a good estimate of what your systolic pressure
should be at any given age. After the age of 50, however, the rule is invalid.

Question 29

What causes the increase in blood pressure with age?

Answer 29

The overall loss of vessel elasticity with age, part of which is due to the increased deposit of cholesterol and other lipid materials in the blood vessel walls.

Question 30

Cold pressor test

Answer 30

A test used to demonstrate the effect of a sensory stimulus (cold) on blood pressure

Question 31

What are the normal and hypertensive responses to the cold pressor test?

Answer 31

In a normal individual the systolic pressure will rise no more than 10 mm Hg, but the rise in a hypertensive individual may be
30 to 40 mm Hg.

Question 32

Diving bradycardia

Answer 32

Some members of each class of tetrapods are able to remain under water for prolonged periods. When animals are submerged, they use oxygen more efficiently and make cardiovascular adjustments. One adjustment is bradycardia, which is associated with a reduction of circulation to all regions of the body except certain vital areas such as heart tissue and the brain. Humans have a more poorly developed diving response, but it can still be observed.

Question 33

The Harvard step test

Answer 33

This test consists of measuring the endurance in stepping up and down a bench 20 inches high (16 inches for women) and the pulse reaction to this exercise. It measures general endurance (not strength, cardiovascular or muscular endurance).

Question 34

What do Harvard step test scores indicate?

Answer 34

Below 55 indicates poor physical condition, with above 90 being excellent

Question 35

Tuttle’s pulse ratio

Answer 35

Defined as the total number of pulse beats counted for one minute

Question 36

Tuttle pulse-ratio test

Answer 36

This test is based on the observation that for the same number of steps, a less fit person will have a relatively higher pulse rate during the two-minute period of recovery immediately after exercise. The cardiovascular efficiency of a person is determined by the amount of exercise required to obtain a 2.5 pulse ratio. This test appears to be fairly accurate for measuring physical condition in the middle range and has also been found to be useful in the
detection of pathological hearts and heart abnormalities.

Question 37

Norms for the Tuttle pulse-ratio test

Answer 37

Boys 10-12: 33 steps
Boys 13-18: 30 steps
Adult man: 29 steps
Adult woman: 25 steps

Question 38

How do exercise and postural changes affect pulse and blood pressure?

Answer 38

Sitting/standing from laying down increases heart rate and blood pressure and running increases both of them even more.

Question 39

Are you vasodilated during exercise?

Answer 39

Depends on which blood vessels you’re referring to. Blood vessels going to skeletal muscle will be dilated, while blood vessels going to organs like the stomach will be constricted.

Question 40

From which direction is a vein refilled?

Answer 40

Veins are refilled by the blood distal to the point of pressure. This is why veins are emptied when pushing proximally but not distally.

Question 41

S1

Answer 41

Number of steps of first test, tuttle pulse ratio

Question 42

S2

Answer 42

Number of steps of second test

Question 43

S0

Answer 43

Number of steps required to obtain a 2.5 ratio

Question 44

r1

Answer 44

Pulse ratio for S1

Question 45

r2

Answer 45

Pulse ratio for S2