![\"\"](\"https:\/\/meddists.com\/wp-content\/uploads\/2018\/07\/pericardium.png\")
<\/a>Layers<\/h4>\n<\/span>\n\n\nFrom inside outwards:<\/p>\n\n\n\n
- Endocardium<\/strong> \u2014 Thin internal layer covering the valves and the chambers, this layer is in direct contact with the blood and receive its nutrients and oxygen by diffusion from the blood<\/li>
- Myocardium<\/strong> \u2014 The thick, middle layer that composed of cardiac muscle<\/li>
- Epicardium<\/strong> \u2014 Thin external layer (composed of mesothelium), which is actually the visceral serous pericardium<\/li><\/ol>\n\n\n\n
![\"\"](\"https:\/\/meddists.com\/wp-content\/uploads\/2018\/07\/heart_layers-600x417.png\")
<\/a>Layers of the heart<\/strong> (Credit: OpenStax, CC BY-SA 4.0<\/a>)<\/figcaption><\/figure>\n\n\n<\/span>\nMyocardium<\/h3>\n<\/span>\n\n\nThe myocardium consists of the following layer orientations within the ventricles, from the outermost towards the innermost:<\/p>\n\n\n\n
- Oblique<\/strong><\/li>
- Circular<\/strong><\/li>
- Longitudinal<\/strong><\/li><\/ol>\n\n\n\n
These muscle fibers are attached to the fibrous skeleton of the heart.<\/p>\n\n\n<\/span>\nNeurovasculature<\/h4>\n<\/span>\n\n\nBlood supply<\/td> Coronary arteries<\/strong>
Capillary beds of the myocardium,<\/strong>\u00a0which allows bi-directional communication between the smallest cardiac veins, and the lumen of the heart within the four chambers<\/td><\/tr> Venous drainage <\/td> The\u00a0coronary sinus<\/strong>\u00a0via great, middle, and small cardiac veins
The\u00a0smallest cardiac veins<\/strong><\/td><\/tr>Innervation<\/td> Cardiac plexus (described in-depth in the\u00a0Innervation of the Heart<\/a>\u00a0lesson)<\/td><\/tr>Lymphatic drainage<\/td> Subepicardial plexus, draining to the anterior and posterior mediastinal nodes, which drain to the bronchomediastinal nodes<\/td><\/tr><\/tbody><\/table>Table 1.<\/strong> A summary of the neurovasculature of the heart.<\/figcaption><\/figure>\n<\/span>
<\/a>Myocardium<\/h3>\n<\/span>\n\n\nThe myocardium consists of the following layer orientations within the ventricles, from the outermost towards the innermost:<\/p>\n\n\n\n
- Oblique<\/strong><\/li>
- Circular<\/strong><\/li>
- Longitudinal<\/strong><\/li><\/ol>\n\n\n\n
These muscle fibers are attached to the fibrous skeleton of the heart.<\/p>\n\n\n<\/span>\nNeurovasculature<\/h4>\n<\/span>\n\n\nBlood supply<\/td> Coronary arteries<\/strong>
Capillary beds of the myocardium,<\/strong>\u00a0which allows bi-directional communication between the smallest cardiac veins, and the lumen of the heart within the four chambers<\/td><\/tr> Venous drainage <\/td> The\u00a0coronary sinus<\/strong>\u00a0via great, middle, and small cardiac veins
The\u00a0smallest cardiac veins<\/strong><\/td><\/tr>Innervation<\/td> Cardiac plexus (described in-depth in the\u00a0Innervation of the Heart<\/a>\u00a0lesson)<\/td><\/tr>Lymphatic drainage<\/td> Subepicardial plexus, draining to the anterior and posterior mediastinal nodes, which drain to the bronchomediastinal nodes<\/td><\/tr><\/tbody><\/table>Table 1.<\/strong> A summary of the neurovasculature of the heart.<\/figcaption><\/figure>\n<\/span>
These muscle fibers are attached to the fibrous skeleton of the heart.<\/p>\n\n\n<\/span>\nNeurovasculature<\/h4>\n<\/span>\n\n\n
Blood supply<\/td> Coronary arteries<\/strong>
Capillary beds of the myocardium,<\/strong>\u00a0which allows bi-directional communication between the smallest cardiac veins, and the lumen of the heart within the four chambers<\/td><\/tr> Venous drainage <\/td> The\u00a0coronary sinus<\/strong>\u00a0via great, middle, and small cardiac veins
The\u00a0smallest cardiac veins<\/strong><\/td><\/tr>Innervation<\/td> Cardiac plexus (described in-depth in the\u00a0Innervation of the Heart<\/a>\u00a0lesson)<\/td><\/tr> Lymphatic drainage<\/td> Subepicardial plexus, draining to the anterior and posterior mediastinal nodes, which drain to the bronchomediastinal nodes<\/td><\/tr><\/tbody><\/table>