Which of the following classic feedback loops involving the ventral respiratory
ID: 3513030 • Letter: W
Question
Which of the following classic feedback loops involving the ventral respiratory group (VRG) describes what would happen when the CO2 level increased in the blood as a result of phosgene gas exposure?
The transport of oxygen and carbon dioxide in the blood is critical for survival. The victims with the most severe symptoms would need mechanical ventilation to overcome the inability of their respiratory systems to maintain normal blood levels of oxygen and carbon dioxide. Phosgene gas would reduce the amount of oxygen available for transport to the tissues. In addition, the metabolic waste product carbon dioxide is transported by three mechanisms back to the alveoli in the blood. Here carbon dioxide crosses the respiratory membrane, driven by a pressure gradient that favors its exit via the lungs during exhalation.
(a) What are the three mechanisms that facilitate CO2 transportation in the blood?
(b) Which mechanism transports the majority of CO2 back to lungs?
(c) By knowing which mechanism transports the most CO2, predict what would happen to the blood pH if the CO2 level dramatically increased?
Some of the victims would undoubtedly continue to decompensate, or experience worse symptoms despite supplemental oxygen. These would be the patients put on high PEEP mechanical ventilation.
(a) Where are the central chemoreceptors and the peripheral chemoreceptors located?
(b) Before the victims are placed on high PEEP mechanical ventilation, what events would you expect central and peripheral chemoreceptors to initiate when a high PCO2 or a low PO2 level in the blood is detected?
a. An increased carbon dioxide level would indirectly cause the VRG to increase pulmonary ventilation, a negative feedback mechanism called hyperventilation.Explanation / Answer
Answer- increased in level of co2 will cause stimulation of vrg ,a positive feedback and causes hyperventilation.VRG are expiratory neurons located bilaterally in nucleus ambigius and nucleus retroambigualis.these neurons don't fire during normal breathing.these firing increases only during forceful breathing associated with exercise.
Answer-a-co2 is transported as
As bicarbonate form
As carbamino compound form bound with hemoglobin.
In dissolved form.
Answer -b-bicarbonate form is major form of co2 transport.
Answer-a-as co2 is a acidic gas, whenever it's Concentration increases bicarbonate tries to neutralise it's acidic effect.but we have limited amount of bicarbonate in our body.so whenever concentration of co2 rises beyond a certain limit,blood pH falls.
Answer3-a-peripheral chemoreceptors are located in carotid bodies and aortic bodies.
Central chemoreceptors are present in brain.these are located in central surface of medulla, nucleus of tractus solitarius,locus ceruleus and hypothalamus.
Answer-3-b-peripheral chemoreceptors are stimulated by fall in pH,hypoxia,rise in co2.once stimulated peripheral chemoreceptors produces hyperapnea, bronchoconstriction,dilation of upper airway, increased blood pressure, tachycardia.
Central chemoreceptors are stimulated by the rise in co2 causing hyperventilation.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.