Question

Extreme challenges to an animal’s physiology allow us to explore and better understand the function of systems in the body. Please address the following questions regarding the initial reflexive changes (before acclimatization) that occur in response to ascent to altitude.

Outline the initial global reflexes that occur in response to the low PO2 at high altitude. Be sure to include all components of the reflex arcs for cardiovascular and respiratory systems. Compare these global reflexes to local reflexes occurring in the lungs. How do the global and local reflexes address the optimization of the ventilation : perfusion ratio (keeping it close to 1)? Map your answers to (a) and (b) onto this concept. For each of the changes that you mentioned in your answers to (a) and (b), discuss the tradeoffs. What are the downsides to these responses for the cardiovascular and gas exchange functions of the body? You don’t need to go into an elaborate discussion for each point, but can be brief (2-3 sentences). To help focus your thoughts, as part of your answer to (d) be sure to hit on the big picture ideas of: Flow of blood and function in the CV system Gas exchange in the lungs Gas carriage in the blood Picking up/dropping off gases at the tissues Impact on hydration and blood volume

Answer 1

Answer :)

At high altitude, pO2 of air is decreased due to less Oxygen proportion in the air. Therefore, it does fall the pO2 in the blood too. The pCO2 level in the blood falls too because of increased hyperventilation.

The reflex arc at the high altitude has the following components:

The receptors in the sense of pO2 changes are pulmonary stretch receptors.

The sensory neurons are medullary neurons, and carotid and aortic bodies.

Interneurons are C4, C5 respiratory interneurons

Motor neurons are cranial motor neurons and spinal motor neurons

Muscles are the diaphragm, and Intercostal muscles.