The document discusses the anatomy and basic function of the human heart. It describes the three main tissues that make up the heart - the outermost pericardium and epicardium, middle myocardium, and innermost endocardium. It then explains the four chambers of the heart - the two upper atria that receive blood and two lower ventricles that pump blood out. The document outlines the pulmonary and systemic circulations, describing the pathways that oxygenated and deoxygenated blood follow. It also reviews the locations and roles of the heart's five valves in regulating blood flow during heart relaxation and contraction.

1. UNIT 3 NOTES:
Heart Anatomy
&
Basic Function

2. (1) Cardiac Tissues
• Outermost = Pericardium & Epicardium
– Pericardium is a membrane anchoring heart to
diaphragm and sternum
– Pericardium secretes lubricant (serous fluid)
– Epicardium is outermost muscle tissue
• Middle = Myocardium
– Contains contractile muscle fibers
• Innermost = Endocardium
– Lines Cardiac Chambers

5. (2) The Chambers
• Human heart has 4 chambers
– 2 Atria (1 on the left, 1 on the right)
• Superior Chambers = Primary Receiving Chambers
(do not actually pump)
• Blood flows into atria
– 2 Ventricles (1 on the left, 1 on the right)
• Inferior Chambers = Pump the Blood
• Contraction = blood sent out of heart + circulated
• Chambers are separated by septum

7. …To the rest
of the body
Deoxygenated
Blood
…To the
lungs
Oxygenated
Blood

8. (3) Pulmonary Circulation
•
•
Pulmonary = Deoxygenated Blood
Involves Right Side of Heart
•
Pathway:
1.
2.
3.
4.
5.
Superior / Inferior Vena Cava
Right Atrium  Tricuspid Valve
Right Ventricle  Pulmonary Semilunar Valve
Left Pulmonary Artery
Lungs

10. (4) Systemic Circulation
•
•
Systemic = Oxygenated Blood
Involves Left Side of Heart
•
Pathway:
1.
2.
3.
4.
5.
Left Pulmonary Vein
Left Atrium  Bicuspid Valve
Left Ventricle 
Aortic Semilunar Valve
Aorta
All Other Tissues

13. (5) The Valves
•
The AV Valves:
– AV = atrioventricular = between the atrium and ventricles
– Tricuspid Valve
• Right Side
– Bicuspid / Mitral Valve
• Left Side
•
The Semilunar Valves:
– Semilunar = between the ventricles and arteries exiting the heart
– Pulmonary Semilunar Valve
• Right Side
• Exiting out the pulmonary artery going to the lungs.
– Aortic Semilunar Valve
• Left Side
• Exiting out the aorta going to working tissues.

15. (6)
The Valves & Heart Pumping
• When the heart is relaxed…
– Blood passively fills atrium
– Flows right past tricuspid / bicuspid valves
– Semilunar Valves remain shut
• When the heart contracts (pumps)…
– Tricuspid / Bicuspid valves swing up and shut
– Blood ejected out of ventricle
– Semilunar Valves open up