RESPIRATION “Respiration is defined as a metabolic process wherein, the living cells of an organism obtains energy (in the form of ATP) by taking in oxygen and liberating carbon dioxide from the oxidation of complex organic substances.” In this process, “the energy (ATP-Adenosine triphosphate) is produced by the breakdown of glucose which is further used by cells to perform various functions.” INVOLUNTARY CONTROL Involuntary respiration is under subconscious control. 1.The diaphragm 2.Intercostal muscles 3.The primary respiratory muscles These are stimulated by groups of neurons located in the pons and medulla. CONTINUE… The neurons which are present in the pons and medulla they form the respiratory control center. The neurons send impulses to the primary respiratory muscles, by the help of the phrenic and intercostal nerves, which stimulates their contraction. CONTINUE… There are three main groups of neurons involved in respiration: The ventral respiratory group controls expiration The dorsal respiratory group controls inspiration The pontine respiratory group controls the rate and pattern of breathing CONTINUE… Once the neurons stop firing, the inspiratory muscles relax and expiration occurs. Pons Medulla Pneumotaxic center Apneustic center Pons Ventral respirator Group(VRG) Dorsal Respiratory Group(DRG) Medulla Assessory respiratory muscles Internal intercostal muscles External intercostal muscles VOLUNTARY CONTROL Voluntary respiration is under conscious control. It is controlled via the motor cortex in the cerebrum, which receives inputs from the limbic system and hypothalamus. The mechanisms involved aren’t completely understood, but signals are thought to be sent to the spinal cord from the motor cortex, which are then passed onto the respiratory muscles. CONTINUE…