2. “Fun” Warm- Up Heart Brain Lungs Stomach Intestine Liver
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 Jethro Tull

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. Describing the sequence of events in one heart beat
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