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Cardiac diastole is the period of the cardiac cycle when, after contraction, the heart relaxes and expands while refilling with blood returning from the circulatory system. [1] [2] Both atrioventricular (AV) valves open to facilitate the 'unpressurized' flow of blood directly through the atria into both ventricles, where it is collected for the ...
The circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. [1][2] It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and from Latin vascula ...
The cardiac conduction system (CCS, also called the electrical conduction system of the heart) [1] transmits the signals generated by the sinoatrial node – the heart 's pacemaker, to cause the heart muscle to contract, and pump blood through the body's circulatory system. The pacemaking signal travels through the right atrium to the ...
The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs. In the lungs the blood is oxygenated and returned to the left atrium to complete the circuit.
Anatomical terminology. [ edit on Wikidata] The heart is a muscular organ found in most animals. This organ pumps blood through the blood vessels of the circulatory system. [ 1 ] The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. [ 2 ]
The cardiac cycle at the point of beginning a ventricular systole, or contraction: 1) newly oxygenated blood (red arrow) in the left ventricle begins pulsing through the aortic valve to supply all body systems; 2) oxygen-depleted blood (blue arrow) in the right ventricle begins pulsing through the pulmonic (pulmonary) valve en route to the lungs for reoxygenation.
The heart has the shape of a pyramid, with its apex pointing towards the left nipple while its base forms the posterior surface of the heart. Other surfaces are the anterior, inferior (or diaphragmatic), and two pulmonary surfaces facing the lungs. Its longest dimension (apical to base) is broadly 12–13 cm, while the average weight is 250 ...
The heart valves and the chambers are lined with endocardium. Heart valves separate the atria from the ventricles, or the ventricles from a blood vessel. Heart valves are situated around the fibrous rings of the cardiac skeleton. The valves incorporate flaps called leaflets or cusps, similar to a duckbill valve or flutter valve, which are ...