When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Heart - Wikipedia

    en.wikipedia.org/wiki/Heart

    The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. [1] Heart and blood vessels together make the circulatory system. [2] The pumped blood carries oxygen and nutrients to the tissue, while carrying metabolic waste such as carbon dioxide to the lungs. [3]

  3. Heart development - Wikipedia

    en.wikipedia.org/wiki/Heart_development

    Heart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos.

  4. Cardiac cycle - Wikipedia

    en.wikipedia.org/wiki/Cardiac_cycle

    In a healthy heart all activities and rests during each individual cardiac cycle, or heartbeat, are initiated and orchestrated by signals of the heart's electrical conduction system, which is the "wiring" of the heart that carries electrical impulses throughout the body of cardiomyocytes, the specialized muscle cells of the heart.

  5. Pacemaker current - Wikipedia

    en.wikipedia.org/wiki/Pacemaker_current

    The pacemaker current (I f, or I Kf, also called funny current) is an electric current in the heart that flows through the HCN channel or pacemaker channel. Such channels are important parts of the electrical conduction system of the heart and form a component of the natural pacemaker.

  6. 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 ...

  7. Cardiac excitation-contraction coupling - Wikipedia

    en.wikipedia.org/wiki/Cardiac_excitation...

    This rate can be altered, however, by nerves that work to either increase heart rate (sympathetic nerves) or decrease it (parasympathetic nerves), as the body's oxygen demands change. Ultimately, muscle contraction revolves around a charged atom (ion) , calcium (Ca 2+ ) , [ 3 ] which is responsible for converting the electrical energy of the ...

  8. “You Can’t Make This Up”: 30 Retail Workers Recall Their ...

    www.aol.com/50-retail-workers-share-t-090028086.html

    Image credits: VonYellow To find out how this conversation started in the first place, we reached out to Reddit user Professional_Song419, who invited retail workers to share their "you can't make ...

  9. Heart sounds - Wikipedia

    en.wikipedia.org/wiki/Heart_sounds

    These are the first heart sound (S 1) and second heart sound (S 2), produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs , adventitious sounds , and gallop rhythms S 3 and S 4 .