Give an account of the Sympathetic Nervous System and Intrisic (autoregulation) in Redirecting blood to Exercising Tissues

: Give an account of the Sympathetic Nervous System and Intrinsic (auto-regulation ) in Redirecting blood to Exercising Tissues

p : language As per the and subject matter . No deviation . Must be authentic Exercises seem to be a challenge to the circulatory system . The skeletal muscles require large amounts of blood supply that have to be increased ruing physical activity . In athletes who have well-trained the cardiac output has to rise to 6 to 7 times that of normal , whereas in non-athletes it increases to 4 to 5 times that of normal (Guyton 2006 p

At rest , two to four ml of blood flows through every 100 grams skeletal muscle on an average , every minute (Ganong , 2003 . In strenuous exercises (only in athletes who have well-trained ) the blood flow can rise to 15 to 25 times that of normal to about 50 to 80 ml per minute for 100 grams of skeletal muscles , every minute (Guyton , 2006

A graph demonstrating the flow of blood through the calf muscles before exercises , during and after the exercises is demonstrated . Strong leg exercises were performed for about six minutes . The exercises that were performed were strenuous in nature . As the muscular contractions were increased , the blood flow at that point of time decreased . Usually when muscles contract to more than 10 of their maximal contraction capacity , they begin to exert some amount of pressure on the arteries that supply the blood . The blood flow is completely ceased when the muscles contract to more than 70 its maximum contraction capability When the contractions were reduced , the blood flow increased at that point of time . Hence , in between the contractions of muscles , the blood flow was increased (Ganong , 2003 . This rhythmic cycle continued during the period exercises were performed . After the exercises were completed , the blood flow in the arteries stayed high for a few minutes and then returned to normal . Severe uncontrollable contractions of the muscles are known as `tetanic contractions (Guyton , 2006 . Some studies have even demonstrated that blood flow to the muscles may even rise before the exercises are performed suggesting a neural control mechanism (Ganong , 2003 . The blood flow to the active muscle groups during exercises can be accurately measured with Xenon washout technique with portable using light-weight CdTe (Cl ) detectors . Noninvasive techniques such as plethysmography and Doppler do not seem to be effective in measure the blood flow during exercises . These techniques can only be used to determine the blood flow during rest

The capillaries that supply the muscles at rest have little or no blood supply . They begin to open up during exercises . As the capillaries open up , the nutrients and the oxygen have to diffuse to a shorter distance in to reach the muscle cells and tissue requiring oxygen and nutrients (Guyton , 2006 . The capillary surface areas in fact increase to two to three times that of normal (Guyton , 2006 . The number of open capillaries increase to about 10 to a 100 times that of normal . Once...