1-How do Respiratory, cardiovascular, neuromuscular systems differ between physically fit and sedentary individuals? Overall a sedentary individual is unconditioned and if they perform an activity more strenuous than they are accustomed to, they run the risk of a myocardial infarction from a higher oxygen demand on the heart that the body can not compensate for. An athlete is conditioned and the body can adapt well to increased oxygen demands on the heart and lungs. Differences:
Blood- During exercise the blood volume decreases because fluid diffuses from the plasma into the intracellular fluid. There are a few reasons as to why this happens, the shifting of fluid from the plasma into the intracellular fluid, during exercise. !- sweating, which decreases blood plasma volume
2-Increased blood pressure forces fluid out of the plasma 3-During exercise your body uses stored glycogen when that is depleted the body will acquire a buildup of lactic acid from the muscles tearing. (That is how you build muscle; it tears and then heals, then gets larger and stronger.) This lactic acid is produced to be used for fuel. An athlete`s muscles are adapted to use the larger quantities of lactic acid. Whereas a sedentary individual is not, their muscles would hurt and burn and fatigue much faster than that of a fit person. ( http://wiki.answers.com/Q/What_does_lactic_acid_do_while_exercising) However there is a buildup of creatine which comes from muscle injury. The byproducts of muscle metabolism increases the osmotic gradient, thus pulling water, increasing blood pressure, which pushes more fluid into the interstitial space. These factors together can cause blood volume to drop, which would cause the hematocrit to drop as well. Cardiac output- A normal cardiac output is about 300 liters an hour or broken down to minutes is 5...