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  2. Control of ventilation - Wikipedia

    en.wikipedia.org/wiki/Control_of_ventilation

    Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and balancing of carbon dioxide by the body as a whole, or by individual cells in cellular respiration. [1] The most important function of breathing is the supplying of oxygen to the body and balancing of the carbon dioxide levels.

  3. 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 ...

  4. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]

  5. Carbon-based life - Wikipedia

    en.wikipedia.org/wiki/Carbon-based_life

    [16] [17] It is the second most abundant element in the human body by mass (about 18.5%) after oxygen. [18] The most important characteristics of carbon as a basis for the chemistry of cellular life are that each carbon atom is capable of forming up to four valence bonds with other atoms simultaneously, and that the energy required to make or ...

  6. Respiration (physiology) - Wikipedia

    en.wikipedia.org/wiki/Respiration_(physiology)

    In physiology, respiration is the transport of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction to the environment by a respiratory system. [1]

  7. Homeostasis - Wikipedia

    en.wikipedia.org/wiki/Homeostasis

    Changes in the levels of oxygen, carbon dioxide, and plasma pH are sent to the respiratory center, in the brainstem where they are regulated. The partial pressure of oxygen and carbon dioxide in the arterial blood is monitored by the peripheral chemoreceptors ( PNS ) in the carotid artery and aortic arch .

  8. Breathing - Wikipedia

    en.wikipedia.org/wiki/Breathing

    Real-time magnetic resonance imaging of the human thorax during breathing X-ray video of a female American alligator while breathing. Breathing (spiration [1] or ventilation) is the rhythmical process of moving air into and out of the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.

  9. Biomolecule - Wikipedia

    en.wikipedia.org/wiki/Biomolecule

    Most biomolecules are organic compounds, and just four elements—oxygen, carbon, hydrogen, and nitrogen—make up 96% of the human body's mass. But many other elements, such as the various biometals, are also present in small amounts.