Search results
Results from the WOW.Com Content Network
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 ...
The heart is cone-shaped, with its base positioned upwards and tapering down to the apex. [8] An adult heart has a mass of 250–350 grams (9–12 oz). [ 17 ] The heart is often described as the size of a fist: 12 cm (5 in) in length, 8 cm (3.5 in) wide, and 6 cm (2.5 in) in thickness, [ 8 ] although this description is disputed, as the heart ...
The apex beat (lat. ictus cordis), also called the apical impulse, [1] is the pulse felt at the point of maximum impulse (PMI), which is the point on the precordium farthest outwards (laterally) and downwards (inferiorly) from the sternum at which the cardiac impulse can be felt.
The Purkinje fibers have a fast inherent conduction rate, and the electrical impulse reaches all of the ventricular muscle cells in about 75 ms. Since the electrical stimulus begins at the apex, the contraction also begins at the apex and travels toward the base of the heart, similar to squeezing a tube of toothpaste from the bottom.
A slow heart rate of 60 or less beats per minute is defined as bradycardia. A fast heart rate of more than 100 beats per minute is defined as tachycardia. An arrhythmia is defined as one that is not physiological such as the lowered heart rate that a trained athlete may naturally have developed; the resting heart rates may be less than 60 bpm.
It extends from a point in the second left intercostal space, about 2.5 mm. from the sternal margin, obliquely downward, with a convexity to the left, to the apex of the heart. This is contrasted with the acute margin of the heart, which is at the border of the anterior and posterior surface, and in which the acute marginal branch of the right ...
This view is obtained at the apex of the heart and looking toward the base of the heart (where the valves are). In this view, the mitral valve, tricuspid valve, and all four chambers are visible. This view shows the right ventricle from base to apex and is a useful view to estimate RV systolic function.
The crux cordis or crux of the heart (from Latin "crux" meaning "cross") is the area on the lower back side of the heart where the coronary sulcus (the groove separating the atria from the ventricles) and the posterior interventricular sulcus (the groove separating the left from the right ventricle) meet. [1]