“Fun” Warm- Up

2. Take about 2 min and name as many song titles as you can that mention each of the following organs: Heart Brain Lungs Stomach Intestine Liver Example: “Heart shaped box” By Nirvana “Aqualung” by JethroTull “Fun” Warm- Up

3. Cardiovascular System

4. While intricate and vital……

5. It is a simple ONE WAY system!

6. Basic Anatomy- Reference the handout you labeled after yesterday’s test.

7. Heart is a pump with 4 chambers. • 2 Atria on top • 2 Ventricles on bottom • Blood vessels are tubes. • Veins carry blood TO heart • Arteries carry blood AWAY FROM heart

9. The cardiac cycle Describing the sequence of events in one heart beat

10. What does a heart beat sound like?

11. Cardiac Cycle • One complete sequence of ventricular systole and diastole • Cycle of events that occurs as the heart contracts and relaxes • Both sides of heart • Takes approximately 0.8 secs at a heart rate of 72 beats per minute

12. Definitions • Systole = period of ventricular contraction. • Diastole = period of ventricular relaxation. • NOTE:  Normally diastole is longer than systole.

13. Cardiac cycle • General Principles. • Contraction of the myocardium generates pressure changes which result in the orderly movement of blood. • Blood flows from an area of high pressure to an area of low pressure, unless flow is blocked by a valve. • Events on the right and left sides of the heart are the same, but pressures are lower on the right.

14. Why is pressure lower on the right side? • At what point in the cycle does the blood have the farthest to travel to get back to the heart?

15. Atrial systole • The heart is full of blood and the ventricles are relaxed • Both the atria contract and blood passes down to the ventricles • The atrio-ventricular valves open due to blood pressure • 70% of the blood flows passively down to the ventricles so the atria do not have to contract a great amount.

16. Ventricular systole • The atria relax. • The ventricle walls contract, forcing the blood out • The pressure of the blood forces the atrio-ventricular valves to shut (producing the heart sound ‘lub’)

17. Ventricular systole • The pressure of blood opens the semi-lunar valves. • Blood passes into the aorta and pulmonary arteries.

18. Diastole • The ventricles relax • Pressure in the ventricles falls below that in the arteries • Blood under high pressure in the arteries causes the semi lunar valves to shut. This produces the second heart sound, ‘dub’. • During diastole, all the muscle in the heart relaxes.

19. Blood from the vena cava and pulmonary veins enter the atria. • The whole cycle starts again.

25. Electrocardiograms (EKG/ECG) P = atrial excitation QRS = excitation of ventricles T = diastole

26. Control of the Cardiac Cycle • Sinoatrial node (SAN) aka pacemaker – top of right atrium • Atrioventricular node (AVN) – top of the inter-ventricular septum • Purkyne Tissue – runs down the inter-ventricular septum

27. SAN, AVN and Purkyne Tissue

30. SAN, AVN and Purkyne Tissue

32. Cardiac cycle Match the letter on the graph to the following events • Semi-lunar valves open • Atrio-ventricular valves close, • Semi-lunar valves close • Atrio-ventricular valves open

33. atrio-ventricular valves open

34. atrio-ventricular valves close atrio-ventricular valves open

35. semi-lunar valves open atrio-ventricular valves close atrio-ventricular valves open

36. semi-lunar valves open semi-lunar valves close atrio-ventricular valves close atrio-ventricular valves open