Question

You trip and fall and a scalpel ends up between your ribs and breathing becomes difficult. What has happened? How can it be fixed?

After your discharge from the hospital you go out for a nice dinner to celebrate. Puffer fish is on the menu. Turns out your previous patient is the chef and is less than motivated to carefully prepare your dinner. You end up with TTX poisoning. TTX blocks voltage gated sodium channels. How would this affect the firing of action potentials? Untreated, TTX poisoning is fatal due to asphyxiation. How? Would your death be quicker or slower at a high altitude? Why?

Answer 1

1) When a foreign object (scalpel) enters between the ribs, it prevents the rib cage from expanding during inspiration preventing the increase in lung volume and capacity. So, breathing becomes difficult and the foreign object (scalpel) has to be removed carefully without damaging nerves and blood vessels.

2) TTX blocks the voltage gated sodium channels. During action potential, the depolarization face requires opening up of voltage gated sodium channels. TTX by blocking the voltage gated sodium channels prevents the development and firingof action potential. This causes poor respiratory effort leading to asphyxia. In higher altitudes the death would be quicker because of decreased partial pressure of oxygen in the inspired air.