Exercise 33: Human Cardiovascular Physiology: Blood Pressure and Pulse Determination

Interpret the pressure reading for each of the numbers listed. 145/85.

A systolic pressure of 145 mm Hg and a diastolic pressure of 85 mm Hg.

How do venous pressures compare to arterial pressures? Why?

Venous pressures are so much lower than arterial pressures because the veins are further removed from the pumping action of the heart.

At what point in the cardiac cycle is the pressure in the heart lowest?

Ventricular diastole

Auscultate— apical heart beat

5th intercostal space in line with the clavicle

The two monosyllables describing the heart sounds are ______________. The first heart sound is a result of the closure of the ________ valves, whereas the second is a result of the closure of the ____________ valves. The heart chambers that have just been filled when you hear the first heart sounds are ___________, and the chambers that have just been emptied are the _________. Immediately after the second heart sound, both the _______ and _________ are filling with blood.

"lub and dup"; AV; Semilunar; ventricles; atria; ventricles; atria

If an individual's heart rate is 80 beats/min, what is the length of the cardiac cycle?

0.75sec

Auscultate— Closure of the aortic valve

2nd intercostal space at right sternal margin

Artery— at the side of the neck

Common carotid artery

Systole

Contraction of the heart muscle

Artery— On the dorsum of the foot

Dorsalis pedis artery

When are the AV valves closed?

During ventricular systole and early diastole.

Cardiac Cycle

Equivalent to one complete heartbeat— during which both atria and ventricle contract and then relax

Give an example of how sounds might be used to diagnose a heart problem.

If valves do not close tightly, closure is followed by a swishing sound due to the back flow of blood (regurgitation). Distinct sounds, often described as high-pitched screeching, are associate with the tortuous flow of blood through constricted, or stenosed, valves.

Why is measuring pulse pressure important?

It indicates actual working pressure (amount of blood forced out of the heart during systole).

What event results in the pressure deflection called the dicrotic notch?

It is the result of pressure fluctuation that occurs when the aortic valve snaps shut.

What event within the heart cause the AV valves to open?

Mid-to-late diastole

When are the semilunar valves closed?

Mid-to-late diastole, ventricular systole (isovolumetric contraction), early diastole

Which valve is heard most clearly when the apical heartbeat is auscultated?

Mitral

Are both sets of valves open during any part of the cycle?

No

Describe the procedures used to take the pulse.

Palpate pressure points by placing the fingertips of the first two or three fingers of one hand over the artery. Compress the artery firmly as you begin palpating and then immediately ease up on the pressure slightly.

Explain why pulse pressure is different from pulse rate?

Pulse pressure is the difference between systolic and diastolic pressure and the pulse rate is the pressure surges per minute.

What portion of the cardiac cycle decreases with a more rapid heart rate?

Quiescent period

Diastole

Relaxation of the heart muscle

Auscultate—Closure of the tricuspid valve

Right sternal margin of the 5th intercostal space

What causes the systolic sound?

Sounds of turbulent blood flow as it moves through the constructed artery.

What is the name of the instrument used to compress the artery and record pressures in the auscultatory method of determining blood pressure?

Sphygmomanometer

What two factors promote the movement of blood through the heart?

The alternate contraction and relaxation of the chambers, and the opening of closing of valves.

Define pulse.

The alternating surges of pressure (expansion and then recoil) in an artery that occur with each contraction and relaxation of the left ventricle.

What causes the disappearance of the sound?

The artery is no longer restricted and blood flows freely.

Which pulse/ pressure points appeared to have the greatest amplitude? Why?

The common carotid artery because it is pushing against gravity and is closest to the heart.

Define pulse pressure.

The difference between systolic and diastolic pressure.

Diastolic pressure

The pressure during ventricular relaxation

Systolic pressure

The pressure in the arteries at the peak of ventricular contraction

Define blood pressure.

The pressure the blood exerts against any unit area of the blood vessel walls, and it is generally measured in the arteries.

What are the sounds of Korotkoff?

The sounds that indicate the resumption of blood flow into the forearm

At what point in the cardiac cycle is the pressure in the heart highest?

Ventricular systole

What events causes semilunar valves to open?

Ventricular systole (ventricular ejection). When the pressure in the ventricles exceed the pressure in the great vessels exciting the heart.

Are both sets of valves closed during any part of the cycle? If so when?

Yes. Ventricular systole (isovolumetric contraction) and early diastole.

Artery—at the wrist

radial artery

Artery— in front of the ear

superficial temporal artery