Immediate effects of exercise Flashcards
What are the immediate effect of exercise
Increased Cardiac output Increase heart rate Increased stroke volume Increase ventilation Increased Blood pressure Increased arteriovenous oxygen difference Selective redistribution of blood Temperature regulation Increased gaseous exchange Increased oxygen consumption
Increased Cardiac output
during physical activity, the muscles require more fuel and oxygen in order to produce energy for contraction, which is carried to the muscles by the blood. Therefore more blood must be circulated to muscles more quickly which is achieved through increased cardiac output.
Increased heart rate
In order to provide a more rapid supply of blood to the muscles, the rate at which the heart beats increases during exercise.
Increased stroke volume
more venous blood is being returned to the heart from the contraction of the muscles due to activity. Is accompanied by an increase in the strength of the contractions. Not only does the heart fill with more blood nut is ejected with greater force.
Increased blood pressure
in particular systolic pressure, increase due to a higher cardiac output. Blood is travelling through the circulatory system at a faster rate resulting in greater pressure being applied to the artery walls.
Increased arteriovenous oxygen difference
more oxygen is being used up during exercise: concentration of oxygen in arteries (arterial oxygen concentration) is approximately 19ml per 100ml of blood and the concentration of oxygen in the veins (venous oxygen concentration) is approximately 13ml when the body is at rest. During strenuous exercise (19-2=17)
Selective redistribution of blood
distributes blood flow away from non-working areas to active muscles (arteries open up (dilate) and shut down (constrict) selectively.
Temperature regulation
working muscles utilise fuel and oxygen (energy) and produce waste products such as carbon dioxide and heat. To prevent the muscles from overheating, blood act as a temperature regulator by transferring heat from within the body to the skin surface where it is released as perspiration. The evaporation of water from the skin surface acts as a cooling mechanism.
Increased gaseous exchange
During strenuous exercise, the diffusion of carbon dioxide and oxygen between the blood and the alveoli is increased threefold from resting levels.
Increased oxygen consumption
an increase in the amount of oxygen delivered to and used by the working muscles. This is referred to as VO2 (Volume of oxygen consumed). Vo2 increase steadily in proportion to the intensity of the exercise. If exercise continues at a submaximal level, like heart rate, Vo2 will level off after about 3minutes, referred to as the steady state oxygen consumption. VO2 max or maximal oxygen intake is the point where oxygen consumption reaches its limit and consumption will slowly decline and plateau.
