Physiology of the Heart Delmar Learning, a Division of Thomson Learning, Inc.

Transcription

1 Physiology of the Heart 2004 Delmar Learning, a Division of Thomson Learning, Inc.

2 Physiology of the Heart State Standards 35) Outline the structure and functions of the anatomy of the cardiovascular system, paying special attention to the musculature of the walls, the chambers, and the valves of the heart and blood vessels. Locate and demonstrate the circulation of blood through the heart; describe the phases and importance of the cardiac cycle and how heart rate and cardiac output relate to one another. Listen to heart sounds, either digitally or with a stethoscope, to identify the normal and abnormal sounds made during the cardiac cycle. Explain the causes for abnormal sounds encountered.

3 Objectives Determine the cardiac output of the heart by practicing its calculation Determine the mechanism of how heart sounds are made and the best places to hear them Determine normal vs. abnormal heart sounds Practice obtaining pulse and blood pressure

4 PHYSIOLOGY OF THE Stroke volume: HEART Amount of blood ejected (from ventricles) with each beat of the heart (usually 60ml) Cardiac output: The amount of blood ejected from heart per minute Stroke volume x heart rate= cardiac output

5 Discussion Calculate the following Cardiac Outputs. SV of 6ml, HR of 89 SV of 8ml, HR of 53 SV of 6ml, HR of 74 How should you be labeling your answers? 2004 Delmar Learning, a Division of Thomson Learning, Inc.

6 Cardiac Output and Blood pressure Cardiac output and blood pressure are directly related. An increase in cardiac output results in an increased blood pressure. Discussion Where do you measure blood pressure? What might affect a patient s blood pressure? Heart rate?

7 SOUNDS OF THE HEART Lub dub sounds - Sounds made by the valves during the cardiac cycle Lub - sound made when the tricuspid and bicuspid valves close between the atria and ventricles Dub - Caused by semilunar valves in the aorta and the pulmonary artery closing 2004 Delmar Learning, a Division of Thomson Learning, Inc.

8 Heart Sounds Lub 1 st sound heard (closing of the tricuspid and bicuspid valves) Referred to as S1 and heard loudest at the apex of the heart. Discussion: Where is the apex of the heart? Point to it on your own chest Delmar Learning, a Division of Thomson Learning, Inc.

9 2004 Delmar Learning, a Division of Thomson Learning, Inc.

10 Heart Sounds Dub 2 nd sound (closing of the pulmonary valves and the aortic valves) Referred to as S2 Discussion Where are the pulmonary and aortic valves located in relation to the apex of the heart? Use medical directional terms.

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12 Normal Heart Sounds Video M8HYmaDpWpE 44HztDzE1EQ 2004 Delmar Learning, a Division of Thomson Learning, Inc.

13 Abnormal Heart Sounds Murmurs Turbulent blood flow in the heart Due to improper closing of the valves The third heart sound or S 3 is a rare extra heart sound that occurs soon after the normal two "lub-dub" heart sounds (S 1 and S 2 ). S3 is associated with heart failure.

14 Abnormal Heart Sounds Continued The fourth heart sound or S 4 is an extra heart sound that occurs immediately before the normal two "lub-dub" heart sounds (S 1 and S 2 ) It is caused by the atria contracting forcefully in an effort to overcome an abnormally stiff ventricle Delmar Learning, a Division of Thomson Learning, Inc.

15 Abnormal Heart Sounds WjP1fDjbE_s ****Write down each one that is noted on the video. We will research these later Delmar Learning, a Division of Thomson Learning, Inc.

16 Activity Complete Station 2 and 4 on the Cardiac Lab Activity: (Read the explanations and directions carefully) -auscultation of the heart sounds with a stethoscope -palpating pulse sites -obtaining blood pressures **Your lab partner may prefer to hold the stethoscope

17 Individual Activity 1 st : Refer back to the abnormal heart sounds you documented. Research what the cause (related disease or disorder) might be. 2 nd : Explain possible consequences of blood pressure that is too high and too low. Exit Ticket: What does S2 refer to? How do cardiac output and heart rate relate to each other?