Search results
Results from the WOW.Com Content Network
Myelin (/ ˈ m aɪ. ə l ɪ n / MY-ə-lin) is a lipid-rich material that surrounds nerve cell axons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. [1] [2] The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However ...
It winds around the left side of the heart along the atrioventricular groove (coronary sulcus). It supplies the posterolateral portion of the left ventricle. [1] In a minority of individuals, the left circumflex artery gives rise to the posterior interventricular artery, in which cases such a heart is deemed left dominant. [1]
The heart is a muscular organ situated in the mediastinum.It consists of four chambers, four valves, two main arteries (the coronary arteries), and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left ...
It is called the 'obtuse' margin because of the obtuse angle (>90 degrees) created between the anterior part of the heart and the left side, which is formed from the rounded lateral wall of the left ventricle. Within this margin can be found the obtuse marginal artery, which is the a branch of the left circumflex artery.
The left heart has two chambers: the left atrium and the left ventricle, separated by the mitral valve. [8] The left atrium receives oxygenated blood back from the lungs via one of the four pulmonary veins. The left atrium has an outpouching called the left atrial appendage. Like the right atrium, the left atrium is lined by pectinate muscles. [25]
The left coronary artery (LCA, also known as the left main coronary artery, or left main stem coronary artery) is a coronary artery that arises from the aorta above the left cusp of the aortic valve, and supplies blood to the left side of the heart muscle. [citation needed] The left coronary artery typically runs for 10–25 mm, then bifurcates ...
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...
The heart's cardiac skeleton comprises four dense connective tissue rings that encircle the mitral and tricuspid atrioventricular (AV) canals and extend to the origins of the pulmonary trunk and aorta. This provides crucial support and structure to the heart while also serving to electrically isolate the atria from the ventricles. [1]