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experiment on respiratory

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Experiments on Respiration Component 3 A Give an account of the neuronal and chemical control of respiration. Breathing has 2 types of interacting mechanisms, the first interacting mechanisms is the voluntary system, this is near the cerebral cortex and 2nd is the automatic system that is in the medulla oblongata and pons. Neural control occurs in the medullary rhythm city centre, which is found in the medulla oblongata. There are 2 interconnected centres situated in the medullary rhythm city centre, the inspiratory centre and expiratory centre. There are 2 sets of chemoreceptors that exist, these are: * Central Chemoreceptors: Responsive to arterial by way of hydrogen ion concentration in cerebrospinal fluid (CSF). * Peripheral Chemoreceptors: Responsive to arterial, and hydrogen ion concentration. ...read more.


The Increased levels of the concentration of the carbon dioxide are detected by chemoreceptors which live in the medulla oblongata. Once the change in the concentration is detected,Once the change has been detected, the medullary rhythmicity centre is stimulated to increase respiration rate. This means that a greater volume of air is moving in and out of the lungs at a faster rate, which removes more carbon dioxide from the blood and causes the concentration of carbon dioxide to reduce back to a safer level. Decreased levels of carbon dioxide are also detected by the chemoreceptor. When a decrease is detected, then the medullary rhythmicity centre is inhibited so respiration rate decreases as breathing is slower. A decrease in pH of the blood makes it more acidic. ...read more.


In order for the pressure gradient to be established correctly, the volume of the lungs needs to be increased. This is achieved by increasing the volume of the thorax. By contracting the diaphragm and the external intercostals muscles (i.e. ribs move up and out), the thorax length and diameter are both increased respectively. Expiration is a passive process, where air rushes out of the lungs into the atmosphere. Here, the pressure gradient is established where it is higher in the lungs than the pressure found in the atmosphere. For expiration to occur, the thorax needs to reduce its size. This occurs when the diaphragm and internal intercostals muscles relax. Therefore, the thorax will be reduced in length and have a smaller diameter. This results in a decreased size of the lungs, causing the intrapulmonary pressure to rise above atmospheric pressure and results in expelling air from the lungs. ?? ?? ?? ?? - 1 - ...read more.

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