why do we breath?

Question

why do we breath? i know its to live,but my teacher says i need a scientifical answer for my test and im clueless.please help me!!!

Answer 1

Okay. You know you need oxygen to live right, just like you need food to live. But what happens after the food is digested? It needs to come out. The same goes with oxygen (except your lungs double for intake and waste, unlike food :P)

I'll explain it in more detail.

The whole process is called gas exchange. When you inhale, fresh air is taken in to the lung's tiny air sacs called alveoli. There, oxygen is transferred to red blood cells to carry it to the heart to be given out to the rest of the body pretty much. While we're at the heart, we also get rid of the waste (carbon dioxide) formed as a by-product of the oxygen, just like food's nutrients and good stuff is used up, red blood cells get used up and recycled. Think of carbon dioxide as your body's air poop. It's really bad if it stays in the body. Anyways...the heart pushes the oxygen depleted red blood cells away and to the lung where it gets rid of all its carbon dioxide (this is where you exhale), then is refilled up with oxygen. The entire process starts over again and again.

Hope it helps!

Answer 2

To live or we die. Our heart will stop without oxegen, is that scientific? Ask Jeeves or look it up in the wikipediaI don't know for a fact, although I know every living creature breathes, yes yes, even trees!

Answer 3

We breathe in order to bring in oxygen to fee the cells in our bodies, unfortunately we breathe to live, but it also kills us . Just think of oxidation, that is why we get old and worn out.

Answer 4

Check out this lung association website... I'm putting in a link that actually answers the exact question, "why do we breathe".

http://www.sk.lung.ca/content.cfm?edit_realword=kbreathe

Answer 5

In order to provide oxygen for our cells and to eliminate other (bad) gases from the blood.

Answer 6

To add oxygen to the blood which makes our cells healthy and grow.

Answer 7

Breath
From Wikipedia, the free encyclopedia
(Redirected from Breathing)
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For other uses, see Breath (disambiguation).
"Breathing" redirects here. For Greek diacritics, see Diacritics (Greek alphabet).
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.

Contents [hide]
1 Mechanics
2 Gas exchange
3 Control of breathing
4 Relationship to death
5 Respiratory rate
6 Composition of air
7 Gas exchange
8 Cultural significance
9 References
10 See also



[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.


[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 dissolved gasses around the body in the circulation.

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.


[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.

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 centre in 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.

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.

If a healthy person were to voluntarily stop breathing (ie. hold his or her breath) for a enough amount of time, he or she would lose consciousness, and the body will resume breathing on its own.

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.


[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 dysfunction.


[edit] Respiratory rate
Humans typically breathe between 12 and 20 times per minute, with a cell.


[edit] Composition of air
The air we inhale is roughly 78% nitrogen, 21% oxygen and 1% argon, helium, carbon dioxide, and other gases. (% by volume)

Not all of the oxygen breathed in is converted into carbon dioxide; around 13% of what we breathe out is still oxygen. This is what makes resuscitation possible. Also our reliance on this relatively small amount of oxygen can cause overactivity or euphoria in pure or oxygen rich environments.


[edit] Gas exchange
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 dissolved gasses around the body in the circulation.


[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.


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

Answer 8

because we live