Regulation during exercise
There are 3 different factors that regulate the Cardiac Control Centre which are: Hormonal; (Adrenaline and Noradrenaline)
Neural; (Propioceptors/Mechanoreceptors, Chemoreceptors and Baroreceptors) Intrinsic, this also includes 2 different nervous systems which are Sympathetic and Parasympathetic. Intrinsic; (Body temp and Venous return)
There are also 2 different types of nervous systems:
During rest the stimulation of adrenaline and noradrenaline is low, the acetylochline increases to keep heart rate down. During exercise the stimulation of hormonal factors increases so heart rate rises, however the level of acetylcholine decreases. While the body is moving the proprioceptors inform the CCC to ensure muscles get greater supply of blood and the chemoreceptors detect change in chemical composition of blood and inform the CCC to increase heart rate to speed up CO2 removal. The baroreceptors detect change in blood pressure and inform CCC to speed up heart rate and increase blood vessel diameter. The body temperature increases which helps blood flow and speeds up nerve impulse. Finally there’s an increase in venous return due to increased action of muscle pump. Meanwhile at the Cardiac Control Centre all these actions are received via the sensory nerve. Messages sent to SA node via sympathetic nerve fibres, which release adrenaline and noradrenaline to increase heart rate. However after exercise the stimulation of adrenaline and noradrenaline decreases and the stimulation of acetylcholine increases. The baroreceptors detect blood pressure is too high so inform the CCC to slow down heart rate and decrease blood vessel diameter. At the CCC unlike during exercise, now the information is now received via the vagus nerve. Messages are sent to the SA node via parasympathetic nerve fibres, which release acetylcholine to decrease heart rate.
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