The Cardiovascular System, also known as the Circulatory System, is an organ system that aims to circulate blood to and from cells in the body, transporting nutrients and removing waste.
Systemic Circuit: The heart pumps blood to the body through arteries that branch off into smaller blood vessels called arterioles.
The capillaries network allow oxygen and other nutrients to diffuse from the blood and into the cells, while metabolic waste diffuses into the venous capillaries from the cells.
Pulmonary Circuit: Blood then returns to the heart through the veins, and the cycle is repeated.
The heart wall consists of 3 layers:
- EPICARDIUM (a.k.a. visceral pericardium) – outer layer of the heart
- MYOCARDIUM – made up of cardiac muscle
- ENDOCARDIUM – lines the chambers of the heart and the heart valves
The boundaries of the 4 heart chambers are marked by 3 grooves known as sulci:
- Coronary Sulcus a.k.a. Atrioventricular Sulcus
- Anterior Interventricular Sulcus
- Posterior Interventricular Sulcus
The atria are separated by a wall-like structure called interatrial septum. The ventricles are separated by the interventricular septum, with both ventricles having internal ridges called trabeculae carnae.
The heart valves ensure a one-way flow:
ATRIOVENTRICULAR VALVES: Right AV (Tricuspid) Valve which has 3 cusps, and Left AV (Bicuspid) Valve a.k.a. Mitral Valve. Chordae Tendinae connect the valve cusps to the conical papillary muscles on the ventricle floor.
The heart has a beat of its own thanks to the electro-chemical circuit system and its 4 relay stations:
- SA Node
- AV Node
- Bundle of HIS
- Purjinke Fibres
When the aorta leaves the left ventricle, it gives off to the Right Coronary Artery (RCA) and the Left Coronary Artery (LCA).
The RIGHT CORONARY ARTERY supplies the right atrium and the SA Node and gives off to the Right Marginal Branch and the Posterior Interventricular Branch, as well as a small branch to the AV Node.
The LEFT CORONARY ARTERY travels to the coronary sulcus and divides into the Anterior Interventricular Branch/Left Anterior Descending Branch (LAD), and the Circumflex Branch.
Below you can find a collection of videos that can help provide a more visual approach to the Cardiovascular System.
Cardiac Muscle Tissue
Introduction to the Cardiovascular System – Animation
The 3 Heart Wall Layers
The Pericardium
The Epicardium
The Myocardium
The Heart Valves
Coronary Circulation
branches of the aortic arch
Special thanks to the creators of the featured videos on this post, specifically Youtube Channels Registered Nurse RN, Lecturio Medical, The Noted Anatomist, KenHub, CTE Skills, Dr.G Bhanu Prakash Animated Medical Videos and Catalyst University.
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