2007-03-24 08:15:20 · 8 answers · asked by Mark 2 in Science & Mathematics ➔ Biology
The short answer: oxygen debt
When your muscles move, they use energy (glucose). To utilize this energy efficiently, the muscles require oxygen. The muscles maintain a small supply of oxygen. When this runs out and the local blood flow can't supply enough, the glucose is used in-efficiently.
One of the byproducts is lactic acid. This causes a localized decrease in the pH. This causes the hemoglobin-oxygen curve to shift making it easier to off-load oxygen. The use of energy also raises the temperature of the local tissue which in addition to shifting the curve also causes vasodilatation.
The drop in pH also causes an increase in heart rate (as does the adrenergic stimulation) this increases the heart rate and stroke volume which increases cardiac output which increases blood flow to the whole body, but especially to the muscle groups due to the above mentioned local vasodilatation.
This in addition to the normal homeostatic principles that regulate blood flow to tissue and the normal off-loading of oxygen in an area that is relatively hypoxic (normal O2 off-loading gradient).
2007-03-25 13:35:48 · answer #1 · answered by tickdhero 4 · 1⤊ 0⤋
It does that because of the respiratory system steup so that when unloading oxygens it gets easier to drop the next one. So while the partial pressures in the body make O2 at 104 throughout the capillary bed pulmanary veins and systemic arteries then down to the tissues it then drops to 40 mmHg. The oxygen diffuses into the blood so the CO2 can be exhaled out of the body
2007-03-24 17:25:42 · answer #2 · answered by daysha87_05 1 · 0⤊ 0⤋
Because your blood carries oxygen and the more you exercise the stronger your blood flow. The stronger your blood flow the more oxygen to the skeletal muscles. It's a way your body maintains balance. Not only do we breathe oxygen, we produce oxygen as well. Pretty sweet if you ask me.
2007-03-24 15:30:26 · answer #3 · answered by Jamie R 1 · 0⤊ 1⤋
i'm goin quick so i won't go crazy here...
more oxygen is delivered to skeletal mucles during exercise for the simple idea of supply and demand. if u are running on treadmill, the body senses that the legs (heart, lungs too of course) are demanding more oxygen transfer. there more the cells in the lining of the muscles and blood vessels that are expanding and contracting, send nerve impulses like crazy to the brain that 'we need more help here' so musles and bloold vessels dilate to receive a larger blood flow, u take deeper breaths, your heart beats faster to take in more and pump out more per minute, to fill that need. i can go more but i beleive this is enough to win.
2007-03-24 15:20:57 · answer #4 · answered by firemedic311 3 · 0⤊ 0⤋
Oxygen is carried through your body attached to red blood cells. When exercising, your heart rate increases, which carries blood to muscle tissue faster, which in turn brings oxygen. A higher pulse or heartrate will bring more oxygen over a period of time than a lower pulse or heartrate.
2007-03-24 15:20:14 · answer #5 · answered by treefiter 2 · 0⤊ 0⤋
Oxygen is carried on the RBCs that are moving faster in the increased blood flow that is pumped by increased heart rate throughout the body.
2007-03-24 15:20:04 · answer #6 · answered by Silly me 4 · 0⤊ 0⤋
Because of elevated catabolic reactions that require Oxygen.
2007-03-24 15:21:57 · answer #7 · answered by Life Dynamics 2 · 0⤊ 0⤋
increased heart rate and blood flow
2007-03-24 15:25:00 · answer #8 · answered by Anonymous · 0⤊ 0⤋