Anatomy

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
• 1 on the left, 1 on the right.
• 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