1. Heart Anatomy

2. (1) Cardiac Tissue
Pericardium = Membrane which encloses the entire heart.
Secretes a lubricant called Serous Fluid to reduce friction against heart.
Outermost Layer = The Epicardium
Middle Layer = Myocardium (contains contractile muscle fibers)
Innermost Layer = Endocardium (lines the chambers)

5. (2) The Chambers Heart has 4 chambers. Superior / Top Chambers = Atria
1 on the left, 1 on the right.
Primary receiving chambers.
Inferior / Bottom Chambers = Ventricles
Pumping / Contracting chambers.
The right and left chambers are separated by the Septum.

7. (3) The Veins
Vein = A Blood Vessel that carries blood INTO / TOWARD the heart.
Your heart has 2 main sets of veins:
Superior-Inferior Vena Cava = Carries blood into the right atrium.
Pulmonary Veins = Carry blood into the left atrium.

9. (4) The Arteries
Artery = A Blood Vessel that carries blood AWAY / OUT of the heart.
Your heart has 2 main arteries:
Pulmonary Artery = Carries blood out of the right ventricle.
Aorta = Carries blood out of the left ventricle.

11. (5) The Valves
Valves are used to maintain blood flow in 1 direction, and maintain blood pressure.
Heart has 4 main valves.
AV (Atrioventricular) Valves:
Valves between the atria and ventricles.
Tricuspid Valve = Between the right atrium and ventricle.
Bicuspid (Mitral) Valve = Between the left atrium and ventricle.
Semilunar Valves:
Valves between the ventricles and exiting arteries.
Pulmonary Semilunar Valve = Exits out the Pulmonary Artery.
Aortic Semilunar Valve = Exits out the Aorta

13. (6) The Pulmonary Circuit
Carries deoxygenated blood through the right side of the heart, and to the lungs.
Path:
S/I Vena Cava
Right Atrium
Tricuspid Valve
Right Ventricle
Pulmonary Semilunar Valve
Pulmonary Artery

15. (7) The Systemic Circuit
Carries oxygenated blood from the lungs, through the left side of the heart, and out to working muscles.
Path:
Pulmonary Veins
Left Atrium
Bicuspid Valve
Left Ventricle
Aortic Semilunar Valve
Aorta

17. The Cardiac Conduction Cycle

18. (1) What Is The Cardiac Conduction System?
The mechanisms behind making your heart beat and pump blood.
All mechanisms are involuntary and controlled by the autonomic nervous system.
Heart Rate increases or decreases depending on the body’s interpreted need for oxygen.

19. (2) Depolarization of the Heart
Nerve Cells are naturally polarized.
Depolarizing a nerve cell, allows it to send a “message” to and from your brain.
Nerve “messages” control your heart beat.
Path:
Nerve Impulse sent from the SA Node to the AV Node in the heart.
Slight atrial vibration.
Nerve Impulse sent to the AV Bundle.
Strong Ventricle contraction.
Blood ejected out of the arteries.

20. (3) The SA & AV Node Node = An intersection of nerves The SA Node:
Sinoatrial Node
In the right atrium
The “Pacemaker” of the heart
Starts each heart beat and sets heart rate.
The AV Node:
Atrioventricular Node
Near the left atrium

22. (4) The Cardiac Cycle
While the heart muscle is being depolarized, it is also properly filling with and ejecting blood.
This Cycle Happens in 2 Phases:
Diastole
Systole

23. (5) Diastole Relaxation of the heart. During this the:
AV Valves are open.
Semilunar Valves are closed.
Blood flows into the atria, and down into the ventricles
At the very end of Diastole there is a very slight vibration in the atria, causing the remaining blood to drop down into the ventricles.

26. (6) Systole Contraction of the heart. During this the:
AV Valves are closed.
Semilunar Valves are open.
Blood is ejected out of the ventricles.

29. (7) Heart Beat
Heart Beat = Sound of your AV Valves closing, followed by your Semilunar Valves closing.
Auditory representation of the 2 phases of the cardiac cycle.
When Listening:
Should not hear blood flow or disturbance.
Noises could represent a clot or block to blood flow.

30. (8) Blood Pressure Blood always flows HIGH TO LOW pressure.
During Systole: (~120)
Heart is contracting
Forceful Ejection of blood
Higher Pressure reading
During Diastole: (~80)
Heart is relaxed
Lower Pressure reading
Hypertension = Higher than normal blood pressure
Hypotension = Lower than normal blood pressure