Prepared By: Erina Suvinna Binti Brahim 06B0581

Recap on previous lesson: What is circulatory system? The transport system which carries food and other substances around the body. What are the two parts of the circulatory system? i) Heart ii) Blood vessels What are the three kinds of blood vessels? i) Arteries ii) Veins iii) Capillaries

HEART STRUCTURES

LETS WATCH MOVIE HAPPY WATCHING

OBJECTIVES: At the end of the lesson, students should be able to: i) State the function of the heart ii) Identify and label the main parts of the heart and the main blood vessels iii) State the reason why the wall of the left ventricle is thicker than the wall of right ventricle

HEAR T - Size: About the size of your fist. - Position: Between the lungs and behind the sternum, a little to the left. - The walls of the heart are made up of muscles. - Function: To pump blood to all parts of the body.

THE POSITION OF THE HEART

HEART STRUCTURE There are 4 chambers of heart: Upper chambers: atrium (atria) i) Right atrium ii) Left atrium Lower chambers: ventricles iii) Right ventricle iv) Left ventricle

HEART STRUCTURE OXYGENAT ED BLOOD DEOXYGENATE D BLOOD PULMONARY ARTERY AORTA PULMONARY VEIN VALVE VENA CAVA RIGHT ATRIUM RIGHT VENTRICL E LEFT VENTRICLE LEFT ATRIUM RIGHT SIDE LEFT SIDE

Valves: To prevent the back flow of blood. Different thickness of ventricles: The wall of left ventricle is thicker than the wall of right ventricle. Why is that so? Because it has to withstand the high pressure of blood in order to pump blood to the rest of the body.

VALVES

- Heartbeat rate: The number of beats in one minute. - Pulse: It is a wave of blood flows along the arteries every time the heart pumps. - Pulse rate: The number of pulses per minute. It is the same as the heartbeat rate. PRACTICAL ACTIVITY 15.3 INVESTIGATING HEARTBEAT AND PULSE RATE

PART A: Listening to the heartbeat DEMONSTRATION Two volunteers: 1 boy and 1 girl Instrument: Stethoscope Procedure: - Sit quietly - Use the stethoscope - Count the number of beats in one minute.

PART B: Measuring pulse rate HOW TO ASSESS YOUR PULSE RATE? Procedure: i) At Rest - Sit quietly - Place your fingertips either on your wrist or neck. - Measure your pulse rate in one minute. ii) After running - Immediately, Place your fingertips either on your wrist or neck. - Measure your pulse rate after running in one minute. WARNING!!! - DO NOT put heavy pressure on your carotid arteries!

WRIST PULSE SITE NECK PULSE SITE

MEASURING PULSE RATE 1) At Rest (when in relaxed) a) Resting pulse rate = ______ beats per minute 2) After running (after running in place for 1 minute) a) Pulse rate after running = ______ beats per minute b) Why does your pulse rate increase after running? It is because the body cells need more energy so the heart beats faster in order for more nutrients and oxygen to reach the cells.

Do you know that your resting heart rate is related to your fitness level?

SUMMAR Y: - The walls of heart are made of - Function of heart: - The heart has FOUR chambers: i) Right atrium ii) Left atrium iii) Right ventricleiv) Left ventricle MUSCLE S. To pump blood to all parts of the body.

HEART STRUCTURE OXYGENAT ED BLOOD DEOXYGENATE D BLOOD PULMONARY ARTERY AORTA PULMONARY VEIN VALVE VENA CAVA RIGHT ATRIUM RIGHT VENTRICL E LEFT VENTRICLE LEFT ATRIUM RIGHT SIDE LEFT SIDE

SUMMARY : - Function of valves: To prevent the back flow of blood - The left ventricle is the thickest because it has to withstand the high pressure of blood in order to pump blood to the rest of the body

EXERCISE 1. The diagram below shows the cross section of a human heart. (a) Label structures A, B. C, D, E, F, G, H and I. A: aorta B: vena cava C: right atrium D: right ventricle E: pulmonary artery F: pulmonary vein G: left atrium H: valves I: left ventricle

(b) State the function of structure labelled H. H (valves): To prevent the back flow of blood (c) The muscular wall of I is thicker compared to the muscular wall of structure D. Explain why? Because it has to withstand the high pressure of blood in order to pump blood to the rest of the body. (d) Give two differences between structures A and B. i) A (aorta): It is an artery of the heart. B (vena cava): It is a vein of the heart. ii) A: It carries oxygenated blood away from the heart. B: It carries deoxygenated blood back to the heart.

Key Questions - How does your heart rate change after exercise? - What can change your heart rate besides exercise?

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