University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

380

Pages:

3
Author:

Mariam A. A.

Factors Affecting Respiration Control Effect of saporin on breathing Saporin is a toxin that destroys NK-1 receptors. This does not allow NK-1 to bind which will not be able to exert its’ effect via the Gaq pathway of stimulating pre-Boz. This will as a result inhibit inspiration leading to hypoxemia and/or hypercapnia. Slow vs Fast Adapting Stretch Receptors • • • • Slow adapting stretch receptors are receptors that detect changes in lung volumes. These are found within the submucosal smooth muscles in the membranous posterior wall of the trachea and central airways. Fast adapting stretch receptors irritants, inflammation and changes in lung volume Both of these will send signals via the vagus nerve to the brain either to pre-Boz or RTN/pFRG to cause increased inspiration or expiration respectively, according to what is required. Irritant receptors are J and C fibres. They can also detect pulmonary congestion. Ad are usually found in the airways. Herring-Breuer reflex The Herring Breuer reflex acts as protective mechanism against too much deflation or inflation. For example, if there is too much inflation this will be detected by the slow adapting stretch receptors, carried via the vagus nerve to the pons. In there, it will inhibit the apneustic centre and thus inhibiting inspiration. There will also be stimulation of the RTN/pFRG which will stimulate expiration causing deflation. On the other hand, if there were to be too much deflation this will also be detected by the slow adapting stretch receptors, and a signal will be varied through the vagus nerve, to the pons. This will cause the stimulation of the pre-Boz complex and inhibition of the RTN/pFRG, these as a result will stimulate inspiration (inflating) and inhibit expiration (deflating) respectively. Therefore, it becomes clear that without this reflex, there will be too much inflation which can cause rupture leading to diseases such as pneumothorax or too much deflation which will cause lung collapse. In either cases these will lead to decreased gas exchange. Practice Question 1. A patient is given morphine. a. Explain the effect of this drug on respiration (2 marks) b. If a patient has morphine overdose how would you manage this? (1 mark) Answer a. Morphine is an opioid drug that binds to opioids receptors found on the pre-Boz. The preBoz complex has high concentrations of this receptors, thus an overdose can have dramatic effects. This is because opioids in the pre-Boz complex increase the conductance of K+ channels, therefore causing a hyperpolarization as K+ goes out so the mV will decrease. This as a result, will decrease inspiration and increase the time for expiration. This is because it will decrease diaphragm and intercoastal muscle activity. This will decrease the frequency of breathing BUT not the depth. b. By giving opioid receptor antagonists such as Naloxone, as these will prevent the drug for binding