La irritabilidad es la capacidad de un organismo o de una parte del mismo para identificar un cambio negativo en el medio ambiente y poder reaccionar. ... Pero principalmente la irritabilidad es la capacidad homeostática que tienen los seres vivos de responder ante estímulos que lesionan su bienestar o estado.
Since the sympathetic nervous system activates the 'fight or flight' response, I'd say the sympathetic nervous system was damaged by the injury.
Hope this answered your question.
Calcium. I definitely make sure for this answer
Fungus!
animals eat things to get their nutrients as opposed to absorption. fungi do not photosynthesize.