The myocardium, the thick, muscular middle layer of the heart, pumps blood. This layer's contraction and relaxation are responsible for propelling blood throughout the body.
Understanding the Heart's Layers and Their Functions
The heart has three main layers:
- Epicardium: The outer layer.
- Myocardium: The middle, muscular layer responsible for pumping blood. This layer's powerful contractions force blood out of the heart's chambers.
- Endocardium: The inner layer lining the heart chambers.
The myocardium's unique structure allows for coordinated contractions, efficiently pumping oxygen-poor blood to the lungs and oxygen-rich blood to the rest of the body. The cardiac cycle, the heart's rhythmic pumping action, relies entirely on the myocardium's ability to contract and relax. This process is crucial for maintaining blood circulation and delivering oxygen and nutrients to all tissues.
The provided references consistently highlight the myocardium's role as the primary pumping layer. For example, the British Heart Foundation describes the myocardium as "a thick, muscular middle layer that squeezes (contracts) and relaxes to pump blood out of the heart to the rest of your body." Similarly, StatPearls notes that the heart muscle, or myocardium, is "pumping blood."
