A transport system pump
Heart
Receives oxygen-poor blood from body tissues
Right side of the heart
The blood vessels that carry blood to and from the lungs
Pulmonary Circuit
Receives oxygenated blood
Left side of the heart
The blood vessels that carry blood to and from all body tissues
Systemic Circuit
Two receiving chambers of the heart
- Right Atrium
- Left Atrium
Two main pumping chambers of the heart
- Right Ventricle
- Left Ventricle
The medial cavity of the thorax that encloses the heart
Mediastinum
A double-walled sac that encloses the heart
Pericardium
- Protects the heart
- Anchors it to surrounding structures
- Prevents overfilling of the heart with blood
The fibrous pericardium
A thin, slippery, two-layer serous membrane that forms a closed sac around the heart
Serous Pericardium
The three layers of the heart wall
- Epicardium
- Myocardium
- Endocardium
The superficial visceral layer of the serous pericardium
Epicardium
The middle layer that is composed mainly of cardiac muscle and forms the bulk of the heart
Myocardium
The third layer of the heart wall is a glistening white sheet of endothelium resting on a thin connective tissue layer
endocardium
The four chambers of the heart
- two superior atria (Left and Right)
- two inferior ventricles (Left and Right)
Separates the atria from left and right
The interatrial septum
Separates the ventricles from left and right
interventricular septum
Encircles the junction of the atria and ventricles
Coronary sulcus
The right atrium has two basic parts
- A smoothed-walled posterior part
- An anterior portion in which bundles of muscle tissue, called pectinate muscles, form ridges in the walls
The receiving chambers for blood returning to the heart from the circulation
Atria
Blood enter the right atrium via three veins
- Superior vena cava
- Inferior Vena Cava
- Coronary Sinus
The discharging chambers, the actual pumps of the heart
Ventricles
Pumps blood into the pulmonary trunk which routes the blood to the lungs where gas exchange occurs
Right ventricle
Ejects blood into the aorta
Left ventricle
Irregular ridges of muscles that mark the internal walls of the ventricular chambers
trabeculae carneae
The two valves that prevent backflow into the atria when the ventricles contract
Atrioventricular (AV) valves
The right AV valve, which has three flexible cusps
Tricuspid valve
The left AV valve, which has two flexible cusps
Mitral Valve also known as bicuspid valve
Attached to each AV valve flap are tiny white collagen cords which anchor the cusps to the papillary muscles protruding from the ventricular walls
Chordae Tendineae
The two semilunar (SL) valves that guard the bases of the large arteries issuing from the ventricles and prevent backflow into the associated ventricles
- Aortic Valve
- Pulmonary Valve