Can anyone discuss about the exchange of O2 and CO2 that occur at the alveoli and muscle cells of mammals?
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In the alveoli the exchange is simply the difference in concentraions, diffusion.  The high concentration of oxygen in the lungs and low concentration of oxygen from the pulmonary artery (the opposite for CO2) follow the laws of diffusion.  In muscle cells CO2 is released by the muscle in combination with water to form H2CO3, an acid, as well as lactic acid.  The acidic environment results in what is called a Bohr shift, which decreases the affinity of oxygen to the hemoglobin to which it is attached.  This way the cells in the body can get oxygen on demand: cells with a higher metabolism get priority over cells with lower metabolism.\n\nSide note:\nCarbon monoxide prevents hemoglobin from releasing its oxygen creating an anoxic state.
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Internal Respiration is the exchange of gases between tissues and the blood cells. External Respiration is the exchange of gases between the blood cells and the lungs.\n\nIf you want more information, you can do a quick search on the net, or email me and I'll dig out my old college books and notes.\n\nHope that helps.
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Oxygen breathed into the lungs diffuses into the alveoli, and then passes through into the  capillary walls. Here it turns into oxyhaemoglobin. Carbon dioxide is carried by blood into the alveoli and is breathed out of the lungs.\n\nGases diffuse along pressure gradients. In other words, gases spread from high concentration areas to low-concentration areas.\n\nThe blood in the capillaries arriving at the alveoli is low in oxygen and high in carbon dioxide. Air in the alveoli is high in oxygen and low in carbon dioxide. \n\nTherefore oxygen diffuses into the blood (attaching itself to the haemoglobin), and carbon dioxide diffuses into the alveoli, where it is breathed out.\n\nThe reverse process occurs at the capillaries that surround the muscle fibres
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Insects exchange oxygen and carbon dioxide between their tissues and the air by a system of air-filled tubes called tracheae.  Tracheae open to the outside through small holes called spiracles.  Among the smaller or less active insects, gas exchange though the tracheal system is by simple diffusion.
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To transport Oxygen from the lungs to other tissues, to transport carbon dioxide from tissues to the lungs. White blood cells are used to fight infections. Platelets are used to seal holes in the blood vessels.
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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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AEROBIC AND ANAEROBIC RESPIRATION:\nRespiration is a chemical process, occurring in the mitochondria in the cytoplasm of all living cells, which breaks down sugar to provide energy for the cell\n\n-Aerobic respiration requires the presence of oxygen \n-Anaerobic respiration does not require oxygen \n-Glucose is a source of energy in the cell \n-The chemical that transports and transfers energy in the cell is called ATP (adenosine triphosphate). \nD-uring respiration sugar is broken down into CO2 and water \n-During Respiration the energy compund ATP is made from ADP and inorganic phosphate molecules (Pi) \n-ADP + Pi + energy from respiration  ATP \n-Where energy is required within the cell the reverse reaction takes place \n-ATP  ADP + Pi + energy· \n-Some heat is lost as waste during respiration. \n+Stages of respiration:         \n\nGlycolysis· \n-requires glucose as an energy source \n-Broken down aerobically into pyruvic acid \n-The pyruvic acid is broken down aerobically or anaerobically \n-two molecules of ATP are generated in this stage.         \nAerobic Breakdown\n-Only happens in the presence of oxygen: \n-Pyruvic acid enters the aerobic respiration system \n-CO2 is generated as waste \n-Hydrogen is given energy \n-It is passed on to a hydrogen acceptor molecule \n-It is then called a reduced hydrogen acceptor \n-Hydrogen is passed into another chemical system \n-The waste hydrogen is reacted with the oxygen to make water \n-The energy from the hydrogen is used to turn 36 molecules of ADP into 36 molecules of ATP \n-Giving a total of 38 molecules of ATP for aerobic respiration \n  \nAnaerobic Breakdown\n-In the absence of oxygen pyruvic acid is changed to: \nLactic acid in mammals \n-Alcohol (ethanol) and carbon dioxide in plants and fungi (such as yeast) \n-No further energy is produced \n-Giving a total of 2 molecules of ATP for anaerobic respiration. \n-Lactic acid in muscles leads to fatigue: \n-The reaction in animals is reversible – once oxygen is available the lactic acid is converted back to pyruvic acid. \n-The reaction in plants leading to alcohol is not reversible.
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Diffusion of gas occurs through the one cell layer thick aveoli in the lungs. The speed of diffusion is dependent on different factors, one being the surface area and second the size of the diffusing particles. In the lungs there is ample surface and Oxygen and Co2 are small particles so the rate of diffusion is great. Hemoglobin has a high affinity for O2 in the lungs and a low affinity for CO2. In the tissues the role reverses and hemoglobin has a low affinity for O2 and a greater affinity for CO2. Now in the tissues since they are small molecules O2 and CO2 readily diffuse across the cell membranes and require no special transport mechanisms. This is simple diffusion where gasses are diffusing down their concentration gradient.
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The lungs excrete carbon dioxide (a waste product from metabolism)
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All right, I'm first going to explain, briefly, the structure of the cardiovascular system, and then I'll move on to how the blood transports oxygen specifically.\n\nYour heart pumps blood from the right ventricle to your lungs, where it exchanges carbon dioxide for oxygen, and then continues to your left atria. The left atria pumps the blood to the left ventricle, which pumps blood through your arteries  to your capillaries, where the oxygen is released so that cells can use it. Carbon dioxide is picked up, and the blood continues to the veins, and back to the right atria.\n\nNow, your blood contains red blood cells, which contain two important molecules, hemoglobin and myoglobin. Both have a high affinity for oxygen, so, in your lungs, where there is a high oxygen concentration, oxygen binds to each of these two molecules (until the equilibrium point is reached). The red blood cells are pumped throughout the body. \n\nIn the body, the concentration of oxygen is lower than in the surrounding atmosphere, so the amount of hemoglobin (and myoglobin) which is binding oxygen decreases until it reaches the new equilibrium point. Active tissues use oxygen quickly, forming lots of CO2, which enters the blood, and is converted to carbonic acid by red blood cells, using the enzyme carbonic anhydrase. The change in pH lowers the affinity of hemoglobin for oxygen, so more oxygen is released from other red blood cells near working tissues. The carbonic acid is released back into the blood from red blood cells, where it dissociates into a proton (H+) and a bicarbonate ion. It travels through the blood back to the lungs, where it is converted back into CO2, and diffuses across the transport surfaces of the lungs due to the concentration gradient. Then the cycle starts over.
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The first is surface area. The mammalian lung has a huge number pf alveoli compared to lung structures of reptiles and amphibians. The greater the surface area available for gas exchange, the more efficient will be the gas exhange.\n\nThe second requirement for gas exchange is assisted by the mamallian heart of four chambers as opposed to reptilian and many other hearts. There is an enormous amount of the circulatory system that passes directly to the pulmonary arteries and veins. Thus there is sufficient blood circulation in the lung area to remove oxygen and transfer it to the rest of the body.\n\nComparative biology will show far fewer alveoli in non-mammalian hearts (with the exception of birds). The other thing notable from compataive anatomy is that the mamallian heart (and that of birds) is a four chambered pump that does not mix unoxygenated blood with blood that has been oxygentated.\n\nSurface area and increased opportunities for deoxygenated hemoglobin to accept oxygen due to more efficient heart action.
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squamous cells: function primarily in alveolar gas exchange and fluid balance. \ncuboidal cells: responsible for pulmonary surfactant secretion and metabolism.
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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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when we take in the food during the process of respiration the glucose is broken down to pyruvic acid CH3COC0OH BY THE process of glycolysis , initially by taking oxygen by cytoplasm . when it gets more oxygen the pyruvic acid enters mitochondria and is converted to CO2 AND H20 . This cycle is called KREB's cyle . the synthesis of ATP molecule takes place in the F1 particle of mitochondria . \nthe equaton is \nC6H12O6+O2---->CH3C0COOH + O2--->CO2 + H20 \nthis process is called aerobic trespiration \nrespiration involves oxidation of food ....\nthus kreb cycle is aerobic respiration and increase in oxygen increases it !!!!!\nPLEASE VOTE IT AS THE BEST ANSWER IF YOU LIKE IT ..PLEASE......\nI THINK I HAVE ANSWERED YOUR MANY QUERIES
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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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The alveoli spread into branches called arbor vitae.\nthe alveoli are present in your lungs and help in exchange of gases(oxygen and carbon di oxide)
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Aerobic Respiration\nI  INTRODUCTION \n\nAerobic Respiration,  biochemical process in living things whereby sugars and similar substances, resulting from the digestion of food, are broken down in the presence of oxygen to produce water, carbon dioxide, and energy. "Aerobic" means "with oxygen". The reaction can be represented by the general chemical equation \n\nC6H12O6 + 6O2 → 6CO2 + 6H2O + energy\n\n\nIn words, sugars and oxygen react together to produce carbon dioxide and water with the release of chemical energy. In biology, the term “respiration” is also used for the physical process of breathing in animals, and for the general chemical process in animals, plants, and microbes of obtaining oxygen from the surrounding air or water. To distinguish from these, the biochemical processes of aerobic respiration and the closely related anaerobic respiration are sometimes termed “cellular respiration” (see Metabolism).\n\nII  CHEMICAL RESPIRATION AND ENERGY \n\nAll living organisms require energy to carry out life processes such as bodily growth, repair, and reproduction. This energy is obtained by chemically breaking the energy-rich bonds in organic “fuel molecules”, usually sugars and similar carbohydrates, which are obtained from digested food. In cells, this energy is transferred to molecules of adenosine diphosphate (ADP), which are converted in the process to adenosine triphosphate (ATP). These high-energy ATP molecules are the main immediate source of useable energy for cell activities.\n\nIII  TWO STAGES OF AEROBIC RESPIRATION \n\nThe whole process of aerobic respiration contains more than 20 chemical steps or stages. The first series of stages is known as glycolysis. This occurs in the jelly-like cytoplasm of the cell, and it is anaerobic—that is, it does not require oxygen. It releases only a small proportion of the total energy available from a fuel molecule of glucose or a similar sugar. (The second series of stages is known as the citric acid cycle, tricarboxylic acid cycle, or Krebs cycle. It is aerobic—that is, it requires oxygen. It releases far more energy, compared to glycolysis, from the remainder of each sugar molecule. This series of stages happens inside the tiny organelles (parts inside the cell) called mitochondria. The food molecule is broken down in a step-by-step process that produces ATP molecules at almost every stage.\n\nIV  PRODUCTS OF AEROBIC RESPIRATION \n\nIf one molecule of a sugar such as glucose is broken down completely during aerobic respiration, it yields 38 molecules of high-energy ATP. Up to eight of these come from the first, anaerobic stages (glycolysis). The other 30 are obtained from the second, aerobic or oxygen-requiring stages of the Krebs cycle.\n\nAlmost all organisms, including plants, animals, fungi, and bacteria, use aerobic respiration. It is the reason that we and other animals breathe or respire, to obtain oxygen from air. However, some simpler organisms and cells can respire anaerobically when oxygen is absent. A few organisms, such as microbes at the bottom of the deep sea, are unable to respire aerobically at all. These are known as obligate anaerobes.\n\nAnaerobic Respiration\nI  INTRODUCTION \n\nAnaerobic Respiration, also called anaerobiosis, biochemical process in living things whereby sugars and similar substances, resulting from the digestion of food, are broken down to release energy in the absence of oxygen. "Anaerobic" means "without oxygen". It thus differs from the allied process of aerobic respiration, which requires the presence of oxygen. Life processes such as growth and repair of tissues require energy, and this is obtained by the chemical breaking of bonds in organic molecules such as sugars and other carbohydrates present in digested food. The chemical energy released by this process in cells is transferred to molecules of adenosine diphosphate (ADP), which become converted to adenosine triphosph