Breathing transports oxygen into the body and carbon dioxide out of the body. Aerobic organisms require oxygen to create energy via respiration, in the form of energy-rich molecules such as glucose. The medical term for normal relaxed breathing is eupnoea. Organisms breathe to avoid death from asphyxiation. General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... This article or section should be merged with aerobic metabolism. ... This article or section does not cite any references or sources. ... Cellular respiration describes the metabolic reactions and processes that take place in a cell to obtain biochemical energy from fuel molecules. ... In science, a molecule is a group of atoms in a definite arrangement held together by chemical bonds. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ...

[edit] Mechanics

Breathing in, or inhaling, is usually an active movement, with the contraction of the diaphragm muscles needed. At rest, breathing out, or exhaling, is normally a passive process powered by the elastic recoil of the chest, similar to a deflating balloon. The following organs are used in respiration: mouth, nose, gullet, windpipe, lungs, diaphragm. In the anatomy of mammals, the diaphragm is a shelf of muscle extending across the bottom of the ribcage. ... Male Chest The chest is a part of the anatomy of humans and various other animals. ...

[edit] Gas exchange

Breathing is only part of the process of delivering oxygen to where it is needed in the body. The process of gas exchange occurs in the alveoli by passive diffusion of gasses between the alveolar gas and the blood passing by in the lung capillaries. Once in the [[blood] the heart powers the flow of dissolved gasses around the body in the circulation. General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Gas exchange or respiration takes place at a respiratory surface - a boundary between the external environment and the interior of the body. ... The alveoli (singular:alveolus), tiny hollow sacs which are continuous with the airways, are the sites of gas exchange with the blood. ... Human respiratory system The lungs flank the heart and great vessels in the chest cavity. ... The word capillary is used to describe any very narrow tube or channel through which a fluid can pass. ... The heart and lungs, from an older edition of Grays Anatomy. ...

As well as carbon dioxide, breathing also results in loss of water from the body. Exhaled air has a relative humidity of 100% because of water diffusing across the moist surface of breathing passages and alveoli. Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... This does not adequately cite its references or sources. ...

[edit] Control of breathing

Breathing is one of the few bodily functions which, within limits, can be controlled both consciously and unconsciously. Conscious attention to breathing is common in many forms of meditation, specifically anapana and other forms of yoga. Anapana Sati, meaning mindfulness of breathing (sati means mindfulness, ānāpāna refers to breathing) is a basic form of meditation taught by the Buddha. ... Statue of Shiva performing Yogic meditation Yoga (Devanagari: योग) is a Sanskrit word that has a wide range of different meanings. ...

Unconsciously, breathing is controlled by specialized centers in the brainstem, which automatically regulate the rate and depth of breathing depending on the body’s needs at any time. When carbon dioxide levels increase in the blood, it reacts with the water in blood, producing carbonic acid. The drop in the blood's pH will then cause the medulla oblongata signalling center in the brain to send nerve impulses to the diaphragm and the intercostal muscles, increasing the rate of breathing. While exercising, the level of carbon dioxide in the blood increases due to increased cellular respiration by the muscles, and so breathing rate increases. During rest, the level of carbon dioxide is lower, so breathing rate is lower. This ensures an appropriate amount of oxygen is delivered to the muscles and other organs. It is important to reiterate that it is the buildup of carbon dioxide making the blood acidic that elicits the desperation for a breath much more than lack of oxygen. This automatic control of respiration can be impaired in premature babies, or by drugs or disease. The brain stem is the stalk of the brain below the cerebral hemispheres. ... The correct title of this article is . ... The medulla oblongata is the lower portion of the brainstem. ... Look up diaphragm in Wiktionary, the free dictionary. ... Intercostal muscles are several groups of muscles that run between the ribs. ... Cellular respiration describes the metabolic reactions and processes that take place in a cell to obtain biochemical energy from fuel molecules. ... A top-down view of skeletal muscle Muscle (from Latin musculus little mouse [1]) is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... Premature birth (also known as preterm birth, or preemie) is defined medically as childbirth occurring earlier than 37 completed weeks of gestation. ...

It is not possible for a healthy person to voluntarily stop breathing. If we do not inhale, the level of carbon dioxide builds up in our blood, and we experience overwhelming air hunger. This irrepressible reflex is not surprising given that without breathing, the body's internal oxygen levels drop dangerously low within minutes, leading to permanent brain damage followed eventually by death. However, there have been instances where people have survived for as long as two hours without air; this is only possible when submerged in cold water, as this triggers the mammalian diving reflex.^[1] Submerging the face into water causes the mammalian diving reflex, which is found in all mammals (including humans, although it is less pronounced), but especially in marine mammals (as, for example, whales and seals. ...

If a healthy person were to voluntarily stop breathing (ie. hold his or her breath) for a long enough amount of time, he or she would lose consciousness, and the body will resume breathing on its own. Consciousness is a quality of the mind generally regarded to comprise qualities such as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and ones environment. ...

Hyperventilating causes a drop in CO₂ below normal levels, lowering blood acidity to trick the brain into thinking it has more oxygen than is actually present. Hyperventilating can cause your blood oxygen levels to go to dangerous levels. In medicine, hyperventilation is the state of breathing faster or deeper than necessary, and thereby reducing the carbon dioxide concentration of the blood below normal. ...

[edit] Relationship to death

Breath is sometimes used as a metaphor for life itself, and often "last breath" is the most obvious sign that death has occurred. The association between the end of life and breathing is not absolute, however. As modern treatment can now take over the process of breathing by mechanical ventilation, or cardiopulmonary resuscitation (CPR), breathing can be restarted if it stops. Because of this, modern deaths are now better defined in terms of brain disfunction. This article or section does not adequately cite its references or sources. ... Wikibooks has more about this subject: First Aid/CPR Cardiopulmonary resuscitation (CPR) is an emergency first aid procedure for a victim of cardiac arrest. ... Italic text // ahh addiing sum spiice iin hurr`` For other uses, see Brain (disambiguation). ...

[edit] Respiratory rate

Humans typically breathe between 12 and 20 times per minute.

[edit] Composition of air

The air we inhale is roughly 78% nitrogen, 21% oxygen, 0.96% argon and 0.04% carbon dioxide, helium, water, and other gases. (% by volume) General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... -1...

The permanent gases in air we exhale are roughly 78% nitrogen, 15% to 18% oxygen, 4% to 5% carbon dioxide and 0.96% argon (% by volume). Additionaly vapours and trace gases are present: 5% water vapour, several parts per million (ppm) of hydrogen and carbon monoxide, 1 part per million (ppm) of ammonia and less than 1 ppm of acetone, methanol, ethanol and other volatile organic compounds. General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ...

Not all of the oxygen breathed in is converted into carbon dioxide; around 16% of what we breathe out is still oxygen. The exact amount of exhaled oxygen and carbon dioxide carbon dioxide varies according to the fitness, energy expenditure and diet of that particular person. Also our reliance on this relatively small amount of oxygen can cause overactivity or euphoria in pure or oxygen rich environments. General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ...

[edit] Cultural significance

In Tai Chi Chuan aerobic training is combined with breathing to exercise the diaphram muscles, and to train effective posture, which both make better use of the bodies energy. In music, breath is used to play wind instrument wind instruments and many aerophones. Laughter, physically, is simply repeated sharp breaths. Hiccups and yawns are other breath-related phenomena. Tai Chi Chuan, Tai Chi Chüan or Taijiquan (Traditional Chinese: ; Simplified Chinese: ; pinyin: ; literally supreme ultimate fist) is an internal Chinese martial art often practiced to promote health and longevity. ... Aerobic training is endurance training by aerobic exercise. ... For other types of diaphragm, see Diaphragm. ... Wikipedia does not yet have an article with this exact name. ... A child laughing For the 1930 film see Laughter (film). ... A hiccup is an involuntary spasm of the diaphragm. ... A dog yawning A yawn (synonyms chasma, pendiculation, oscitation from the Latin verb oscitare, to open the mouth wide[1]) is a reflex of deep inhalation and exhalation associated with being tired, with a need to sleep, or from lack of stimulation. ...

[edit] References

1. ^ Ramey CA, Ramey DN, Hayward JS. Dive response of children inrelation to cold-water near drowning. J Appl Physiol 2001;62(2):665-8.Source: Diana Hacker (Boston: Bedford/St. Martin’s, 2002).Adapted from Victoria E. McMillan (Boston: Bedford/St. Martin’s, 2001). See it cited here

• Parkes M (2006). "Breath-holding and its breakpoint.". Exp Physiol 91 (1): 1-15. PMID 16272264.  Full text

[edit] See also

• Agonal breathing
• Cheyne-Stokes respiration
• Biot's respiration
• Mouth breathing
• Pneuma
• Prana
• Qi
• Respiratory rate
• Spirit
• Halitosis