1. Pulmonary Circulation
Conus arteriosus
Superior end of the right ventricle
Leads to the Pulmonary Trunk
Pulmonary Trunk
Divides into Left and Right Pulmonary Arteries
Blood flow:
Right Ventricle -> Pulmonary Trunk through the Pulmonary Semilunar Valve (PSL Valve)
Pulmonary valve has 3 Semilunar cusps

2. Systemic Circulation Blood leaves Left Ventricle through …
Aortic Semilunar Valve (ASL Valve) into Ascending Aorta
Ascending Aorta turns to the left into the …
Aortic arch and becomes the ….
Descending Aorta

3. Systemic Circulation
Structural Differences between the Left & the Right Ventricle:
Left Ventricle
Round
Thicker myocardium wall -> more pressure
Right Ventricle
Pouch shaped
Thinner myocardium wall -> less pressure

4. Coronary Sinus Cardiac veins return blood to coronary sinus
Cardiac sinus opens into Right Atrium

5. Writing Activity (10 points)
You are a Erythrocyte (RBC) traveling through the human body. Describe the journey!
Condition in lungs for O2 pick up
Heart: atria, ventricles, 4 valves
Systemic pathway
Pulmonary pathway
Conditions of tissue for O2 dispersal & CO2 pick up
2 Bonus points: if all possible names for valves are given
Example: Atrioventricular valve, Mitral valve, …

6. Foramen Ovale Before Birth; an opening through the Interatrial Septum
Connects the two Atria
Eliminates blood being sent to the lungs in a Fetus!!
Seals off at birth -> Fossa Ovalis
Blue Baby
Foramen ovale does not deal off after birth
Requires surgery

7. Heart Valves Tricuspid Valve Bicuspid Valve Mitral Valve
Pulmonary Semilunar Valve
Left AV valve:
Bicuspid valve
Mitral valve
Right AV Valve:
Tricuspid
Aortic Semilunar Valve
Pulmonary Semilunar Valve
Aortic Semilunar Valve

8. Cardiac Conduction Heart Beat The entire heart contracts in sequence
A single contraction of the heart
The entire heart contracts in sequence
Atria
Ventricles

9. Cardiac Conduction Structures of the Conducting System
Sinoatrial (SA) nodes
In the wall of the Right Atrium
Atrioventricular (AV) node
Between Atrium & Ventricle
Conducting Cells
Throughout myocardium

10. The Cardiac Cycle
Begins at the Sinoatrial ( SA) Node with an Action Potential
The Action Potential is transmitted through the conducting System:
SA node
AV node
Produces an Action Potential in the Cardiac muscle cells
Contractile cells

11. 5 Steps to the Cardiac Cycle:
Ventricular diastole
Atrial systole begins
Atrial diastole
Ventricular systole 1st phase
Ventricular systole 2nd phase
Diastole = Relaxation
Systole = Contraction

12. 5 Steps to the Cardiac Cycle:
Ventricular diastole
All chambers are relaxed
Diastole = Relaxation
Systole = Contraction

13. 5 Steps to the Cardiac Cycle:
Atrial systole begins
Atria contract & force blood into ventricles
Diastole = Relaxation
Systole = Contraction

14. 5 Steps to the Cardiac Cycle:
Atrial diastole
Atrium contraction ends
Atrium relaxes
Ventricle contractions begin
Diastole = Relaxation
Systole = Contraction

15. 5 Steps to the Cardiac Cycle:
Ventricular systole 1st phase
Contraction pushes AV valves close
Diastole = Relaxation
Systole = Contraction

16. 5 Steps to the Cardiac Cycle:
Ventricular systole 2nd phase
Increase in pressure forces SL valves to open
Blood is ejected
Diastole = Relaxation
Systole = Contraction

17. 5 Steps to the Cardiac Cycle:
Ventricular diastole
Atrial systole begins
Atrial diastole
Ventricular systole 1st phase
Ventricular systole 2nd phase
Diastole = Relaxation
Systole = Contraction

18. Sinoatrial (SA) Node Pacemaker of the heart Initiates heart beak
Sends excitatory impulses every 0.85 seconds
Contracts:
Atrium
Impulse is send to AV node

19. Atrioventricular (AV) Node
Sends impulses to AV bundles
Bundles branch into Purkinje fibers
Cause ventricle to contract

20. Cardiac Cycle

21. Cardiac Cycle - Review
Is the period between the start of one heartbeat and the beginning of the next
Includes contraction & relaxation with the Atria & Ventricle
Systole
Contraction
Diastole
relaxation

22. Phases of the Cardiac Cycle
Atrial systole
Atrial diastole
Ventricular systole
phase 1
Ventricular diastole
Ventricular systole
phase 2

23. Cardio dynamics
Vagus Nerve (Cranial Nerve X) carries fibers to the heart
Cardiac center is in the Medulla Oblongata
Cardio acceleration is controlled by the sympathetic neurons
Cardio inhibition is controlled by the parasympathetic neurons