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  2. Composition of the human body - Wikipedia

    en.wikipedia.org/wiki/Composition_of_the_human_body

    Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...

  3. Heart - Wikipedia

    en.wikipedia.org/wiki/Heart

    Real-time MRI of the human heart The human heart is in the middle of the thorax, with its apex pointing to the left. [15] The human heart is situated in the mediastinum, at the level of thoracic vertebrae T5–T8. A double-membraned sac called the pericardium surrounds the heart and attaches to the mediastinum. [16]

  4. Anatomy of the human heart - Wikipedia

    en.wikipedia.org/wiki/Anatomy_of_the_human_heart

    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 ...

  5. Human body - Wikipedia

    en.wikipedia.org/wiki/Human_body

    The heart works by pumping blood around the body allowing oxygen, nutrients, waste, hormones and white blood cells to be transported. Diagram of the human heart. The heart is composed of two atria and two ventricles. The primary purpose of the atria is to allow uninterrupted venous blood flow to the heart during ventricular systole.

  6. Circulatory system - Wikipedia

    en.wikipedia.org/wiki/Circulatory_system

    In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. [ 1 ] [ 2 ] It includes the cardiovascular system , or vascular system , that consists of the heart and blood vessels (from Greek kardia meaning heart , and Latin vascula meaning vessels ).

  7. Cardiac physiology - Wikipedia

    en.wikipedia.org/wiki/Cardiac_physiology

    Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.

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  9. Cardiac skeleton - Wikipedia

    en.wikipedia.org/wiki/Cardiac_skeleton

    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]