if blood from the alveolus enters the body and leaves the blood and enters the alveolus?
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oxygen and carbon dioxide
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Higher partial pressure of O2 in atmosphere that that present in the blood.\n\nRemember, blood in the lungs will be DEOXYGENATED!
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Its like gas for a car. Blood is a oxygen carrier, and supports all the body organs. If anyone loses too much of it- too bad!
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Every time you exhale, you breathe out most of the air you breathed in. While the air is in your lungs, oxygen travels from air to blood and CO2 from blood to air, in each case moving naturally to where it is less concentrated.\n\nHow long it takes the average oxygen molecule from being absorbed to being breathed out again as part of a carbon dioxide molecule is a really good question - I have no idea if anyone has even calculated it, but we can try.\n\nMost people pass out if their blood oxygen level drops below about 80% - and most people can hold their breath for maybe 4-5 minutes (the record is almost 9 minutes by Houdini, but that's someone trained and a bit freakish). That implies you use 20% of the oxygen in, say, 5 minutes - so it would take 25 minutes to use it all, if that were physically possible.\n\nBTW, I'm prettty sure it's 8-9 pints of blood. The normal O2 reading in arterial blood is around 10-13 kPa, but I'd have to admit I don't know how to convert that to a mass (or free volume) of oxygen.\n----\nOoh, here you go: arterial blood contains about 20ml of oxygen per 100cc. Your blood volume is about 5 litres, so that would mean your body contains rather less than a litre of oxygen (because not all of your blood is fully oxygenated).
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Lung\nFrom Wikipedia, the free encyclopedia\n\nThe lungs flank the heart and great vessels in the chest cavity. (Source: Gray's Anatomy of the Human Body, 20th ed. 1918.)\n\nThe lungs flank the heart and great vessels in the chest cavity. (Source: Gray's Anatomy of the Human Body, 20th ed. 1918.)\nAir enters and leaves the lungs via a conduit of cartilaginuous passageways — the bronchi and bronchioles. In this image, lung tissue has been dissected away to reveal the bronchioles. (Source: Gray's Anatomy of the Human Body, 20th ed. 1918.)\n\nAir enters and leaves the lungs via a conduit of cartilaginuous passageways — the bronchi and bronchioles. In this image, lung tissue has been dissected away to reveal the bronchioles. (Source: Gray's Anatomy of the Human Body, 20th ed. 1918.)\n\nThe lung is the essential organ of respiration in air-breathing vertebrates. Its principal function is to transport oxygen from the atmosphere into the bloodstream, and to excrete carbon dioxide from the bloodstream into the atmosphere. This it accomplishes with the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs where gas exchange takes place. Lungs also have nonrespiratory functions.\n\nMedical terms related to the lung often begin with pulmo-, from the Latin pulmonarius ("of the lungs"), cognate with the Greek pleumon ("lung").\n\nRespiratory function\n\nEnergy production from aerobic respiration often requires oxygen and produces carbon dioxide as a by-product, creating a need for an efficient means of oxygen delivery to cells and carbon dioxide excretion from cells. In smaller organisms, such as single-celled bacteria, this process of gas exchange can take place entirely by simple diffusion. In larger organisms, this is not possible; only a small proportion of cells are close enough to the surface for oxygen from the atmosphere to enter them through diffusion. Two major adaptations made it possible for organisms to attain great multicellularity: an efficient circulatory system that conveyed gases to and from the deepest tissues in the body, and a large, internalised respiratory system that centralized the task of obtaining oxygen from the atmosphere and bringing it into the body, whence it could rapidly be distributed to all tissues via the circulatory system.\n\nIn air-breathing vertebrates, respiration occurs in a series of steps. Air is brought into the animal via the airways — in reptiles, birds and mammals this often consists of the nose; the pharynx; the larynx; the trachea; the bronchi and bronchioles; and the terminal branches of the respiratory tree. The lungs of mammals are a rich lattice of alveoli, which provide an enormous surface area for gas exchange. A network of fine capillaries allows transport of blood over the surface of alveoli. Oxygen from the air inside the alveoli diffuses into the bloodstream, and carbon dioxide diffuses from the blood to the alveoli, both across thin alveolar membranes. The drawing and expulsion of air is driven by muscular action; in early tetrapods, air was driven into the lungs by the pharyngeal muscles, whereas in reptiles, birds and mammals a more complicated musculoskeletal system is used. In the mammal, a large muscle, the diaphragm (in addition to the internal intercostal muscles), drive ventilation by periodically altering the intra-thoracic volume and pressure; by increasing volume and thus decreasing pressure, air flows into the airways down a pressure gradient, and by reducing volume and increasing pressure, the reverse occurs. During normal breathing, expiration is passive and no muscles are contracted.. [\n\nNonrespiratory functions\n\nIn addition to respiratory functions such as gas exchange and regulation of hydrogen ion concentration, the lungs also:\n\n    * influence the concentration of biologically active substances and drugs used in medicine in arterial blood\n    * filter out small blood clots fo
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they transfer oxygen into the blood stream and co2 out\n\nmore here:\n\nhttp://en.wikipedia.org/wiki/Lungs
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Respiratory and circulatory.\n\nRespiratory brings oxygen into your body.  Circulatory pumps blood, which carries the oxygen, to the cells in the rest of your body.
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A gas moves from a high pressure to a low pressure. When you breathe in, the partial pressure of oxygen in the lungs is higher than in the blood. Therefore the oxygen will move from the lungs to the blood. The exact opposite is true for carbon dioxide.
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it happens , the partial perassure of o2 is less in cells than in hemaglobin so it diffusses in to cells frm hemoglbin
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Your heart is a pump that circulates blood through the many veins and arteries in your body...oxygenated blood leaves your heart ,in your arteries, flows to your tissues, organs and cells depositing oxygen then returns through your veins back through your lungs to heart to re oxygenate the the cycle starts over.
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Veins carry deoxygenated blood from the organs and tissues back to the heart.\nDeoxygenated blood from the body enters the right atrium through two great veins, the superior vena cava which drains the upper part of the body and the inferior vena cava that drains the lower part which drains the portal cyrculation too full with nutrients to nourish the body.
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Oxygen bind to hemoglobin which is part of the red blood cells.  It is picked up in the lungs where there are little sacs that have a very thin lining of cells.  Therefore the air you breathe in will be able to reach the blood.  Then the hemoglobin will carry blood to the parts of the body.
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You have an artery on both sides and a vein on the other (jugular) same as all parts of your body. One takes blood to the heart (vein) one back into the body full of oxygen (artery)
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The blood starts flowing quicker and heats up the nasal cavity\nb
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blood, fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries (see circulatory system; heart). An adult male of average size normally has about 6 quarts (5.6 liters) of blood. The blood carries oxygen and nutrients to the body tissues and removes carbon dioxide and other wastes. The colorless fluid of the blood, or plasma, carries the red and white blood cells, platelets, waste products, and various other cells and substances
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carries oxygen around the body
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respiration..\n\nco2 is given off, it goes through our blood stream, reabsorbed by the alveoli, switched out with o2 by respiration