bio202 exercise 33

(see Question 4, p. 506 in Lab Manual) indicate the time interval occupied by the following events of the cardiac cycle. the length of the normal cardiac cycle the time interval of atrial systole the quiescent period, or pause the ventricular contraction period

0.8 sec 1. The length of the normal cardiac cycle 0.1 sec 2. The time interval of atrial systole 0.4 sec 3. The quiescent period, or pause 0.3 sec 4. the ventricular contraction period

Complete the following statements: The monosyllables describing the heart sounds are ____(1)____. The first heart sound is a result of closure of the ____(2)____ valves, whereas the second is a result of closure of the ____(3)____ valves. The heart chambers that have just been filled when you hear the first heart sound are the ____(4)____ , and the chambers that have just been emptied are the ____(5)____ . Immediately after the second heart sound, the ____(6)____ are filling with blood, and the ____(7)____ are empty. (see Question 7, p. 507 in Lab Manual)

1. 2. 3. 4. 5. 6. 7. The monosyllables describing the heart sounds are lub-dub. The first heart sound is a result of closure of the atrioventricular valves, whereas the second is a result of closure of the semilunar valves. The heart chambers that have just been filled when you hear the first heart sound are the ventricles, and the chambers that have just emptied are the atria. Immediately after the second heart sound, the atria are filling with blood, and the ventricles are empty.

(see Question 15, p. 508 in Lab Manual) Assume someone has been injured in an auto accident and is hemorrhaging badly. What pressure point would you compress to help stop bleeding from each of the following areas? 1. the thigh ______ artery 2. the calf ______ artery 3. the forearm ______ artery 4. the thumb _____ artery

1. = Femoral artery 2. = Popliteal artery 3. = Brachial artery 4. = Radial artery

Correctly identify valve closings and openings, chamber pressures, and volume lines, and the ECG and heart sound scan lines of the diagram in Question 1 on page 505 by matching the diagram labels with the terms below.

1. I 2. k 3. n 4. o 5. p 6. g 7. m 8. h 9. f 10. b 11. j 12. l 13. a d e 14. b c

(see Question 19, p. 508 in Lab Manual) Identify the phase of the cardiac cycle to which each of the following apply: 1. systolic pressure 2. diastolic pressure

1. systole or ventricular contraction or ventricular ejection 2. diastole or ventricular relaxation or relaxation

Interpret 145/85/82.

145 = systolic pressure. 85 = diastolic pressure reported as the point where the sound muffles. 82 = diastolic pressure reported as the point where sound disappears.

No one expects you to be a full-fledged physician on such short notice; but on the basis of what you have learned about heart sounds, how might abnormal sounds be used to diagnose heart problems?

Abnormal sounds such as swishing sounds after valvular closure or high-pitched sounds arising when bood is forced through constricted (valve) openings might indicate valvular problems.

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

Alternate contraction and relaxation of the myocardium and opening and closing of the heart valves (which is responsive to pressure gradients).

(see Question 28, p. 509 in Lab Manual) What effect do the following have on blood pressure? (Indicate increase by I and decrease by D.)

D increased diameter of the arterioles I increased blood viscosity I increased cardiac output D hemorrhage I arteriosclerosis I increased pulse rate

(See Question 5, p. 506 in Lab Manuel) If an individual's heart rate is 80 beats/min, the length of the cardiac cycle is ____(1)_____ seconds. The portion of the cardiac cycle shortened by this more rapid heart rate is the ventricular ____(2)_____ period.

If an individual's heart rate is 80 beats/min, the length of the cardiac cycle is .75 seconds. The portion of the cardiac cycle shortened by this more rapid heart rate is the ventricular relaxation or diastole period. (1. 0.75; 2. relaxation or diastole)

How could you tell by simple observation whether bleeding is arterial or venous?

If it spurts, it is arterial. It will flow evenly if it is venous blood.

If both sets of valves are closed during any part of the cardiac cycle, when does this happen?

Momentarily after atrial contraction and ventricular systole.

Define cardiac cycle

One complete heartbeat including atrial and ventricular contraction.

Describe the procedure used to take the pulse.

Place the first 2-3 fingertips of one hand over an arterial pressure point. Compress firmly and then release the pressure slightly to palpate the pulse.

Define blood pressure

Pressure exerted by blood against the walls of the blood vessels.

Define pulse

Pressure surges in an artery occurring during each contraction and relaxation of the left ventricle.

Define pulse pressure. Why is this measurement important?

Pulse pressure is the systolic pressure minus diastolic pressure. It is important because it indicates the actual working pressure (actual amount of blood forced out of the heart during systole).

(see Question 13, p. 507 in Lab Manual) Identify the artery palpated at each of the following pressure points: 1. at the wrist 2. on the dorsum of the foot 3. in front of the ear 4. at the side of the neck

Radial Dorsalis pedis Temporal Carotid

What are the sounds of Korotkoff? What causes the systolic sound? What causes the disappearance of the sound?

Sounds that can be auscultated over a partially occluded artery. The systolic sound is caused by the sound of turbulent blood flow as it first begins to move through the constricted artery.

(see Question 20, p. 508 in Lab Manual) What is the name of the instrument used to compress the artery and record pressures in the auscultatory method of determining blood pressure?

Sphygmomanometer

(see Question 3, p. 506 in Lab Manual)

The AV valves are closed during ventricular systole.

Why do you think the carotid artery appears to have the greatest amplitude when palpating various pressure points?

The carotid artery is the major artery delivering blood to the brain (against gravity and it is closest to the heart).

What event during the cardiac cycle results in the pressure deflection called the dicrotic notch?

The momentary increase in aortic pressure that occurs when its semilunar valves snap shut.

Assume the following BP measurement was recorded for an elderly patient with severe arteriosclerosis:1 70/110/. Explain the inability to obtain the third reading.

The patient's arteries are so narrowed by arteriosclerosis that blood flow is always partially occluded. Hence, the sound.

When are the semilunar valves closed? When are they open?

They are closed during the period of relaxation of the heart as a whole and during atrial contraction. They are open when ventricular pressure is less than atrial pressure.

(see Question 9, p. 507 in Lab Manual) In order to auscultate most accurately, indicate where you would place your stethoscope for the following sounds: a. closure of the tricuspid valve b. closure of the aortic semilunar valve c. apical heartbeat d. which valve is heard most clearly when the apical heartbeat is auscultated?

a. left or right sternal border of fifth intercostal space b. right sternal border of second intercostal space c. fifth intercostal space in line with middle of left clavicle d. bicuspid

(See Question 14, p. 508 in Lab Manuel) When you were palpating the various pulse or pressure points, which appeared to have the greatest amplitude or tension?

common carotid or carotid artery

Define systole

contraction of ventricles

During the cardiac cycle, pressure in the heart is lowest at the point of ventricular __________.

diastole

(see Question 3, p. 506 in Lab Manual) The AV valves close within the heart when ventricular pressure is __________ than atrial pressure.

greater

The semilunar valves open when ventricular pressure is __________ than pressure in the great arteries.

greater

(see Question 3, p. 506 in Lab Manual) The AV valves open within the heart when ventricular pressure __________ than atrial pressure.

less

The semilunar valves close when ventricular pressure is __________ than pressure in the great arteries.

less

Are both sets of valves open during any part of the cycle? (see Question 3, p. 506 in Lab Manual)

no

(see Question 17, p. 508 in Lab Manual) You may sometimes observe a slight difference between the value obtained from an apical pulse (beats/min) and that from an arterial pulse taken elsewhere on the body. What is this difference called?

pulse deficit

(see Question 3, p. 506 in Lab Manual) During the cardiac cycle, pressure in the heart is highest at the point of ventricular __________.

systole

How do venous pressures compare to arterial pressures? Why?

venous pressures are lower because veins are far removed from the pumping action of the heart.

Define diastole

ventricular relaxation

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

yes