Module 13: Heart and Great Vessels
Learning Objectives:
By the end of this class, students will be able to:
- Explain the internal and external anatomy of the heart.
- Describe the pericardium, including its layers, and its functions.
- Distinguish how valves regulate blood flow through the heart.
- Outline the pattern of blood flow through the heart.
- Identify and describe the location, origins, and branches of the coronary blood vessels.
- Describe the general pattern of circulation.
- Describe electrical conduction through the heart.
- Identify and describe the great vessels carrying blood immediately to and from the heart and the major vessels of the thoracic, abdominal, and pelvic cavities.
Terms to Know
General
Pericardium
Heart Anatomy
Heart Development
Cardiac Cycle
*Covered only in lecture, not in this text |
Coronary Circulation
Innervation and Conducting System of the Heart
Great Vessels
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Introduction to the Heart
This content is primarily covered in the reading and assignment as self-study. It will be only briefly reviewed in lecture.
The heart is located within the thoracic cavity, medially between the lungs in the mediastinum. The dorsal surface of the heart lies near the bodies of the vertebrae, and its anterior surface sits deep to the sternum and costal cartilages. The great veins, the superior and inferior venae cavae, and the great arteries, the aorta and pulmonary trunk, are attached to the superior surface of the heart, called the base. The inferior tip of the heart, the apex, lies just to the left of the sternum, and the right surface of the heart sits inferiorly on the diaphragm.
There are two distinct but linked circuits in the cardiovascular system called the pulmonary and systemic circuits. Pulmonary circulation transports blood to and from the lungs, where it picks up oxygen and delivers carbon dioxide for exhalation. Systemic circulation transports oxygenated blood to virtually all of the tissues of the body and returns relatively deoxygenated blood and carbon dioxide to the heart to be sent back to the pulmonary circulation.
THe Pericardium and the heart wall
This content is covered in the assignment and reviewed and built upon in lecture.
Within the mediastinum, the heart is separated from the other mediastinal structures by a tough membrane known as the pericardium, or pericardial sac. The pericardium consists of two distinct sublayers:
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Fibrous pericardium: This is the tough outer layer made of dense connective tissue that protects the heart and maintains its position in the thorax.
- Serous pericardium: The inner serous pericardium consists of two layers designed in a similar way to the pleura surrounding the lungs and the peritoneum of the abdominopelvic cavity:
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- Parietal pericardium: This is the outer layer of the serous pericardium, and it is fused to the fibrous pericardium.
- Visceral pericardium: This inner layer lines the heart itself. It actually forms part of the heart wall, called the epicardium (m