Which structure is at work when the body deals with reflex actions? the heart the brain stem the vertebral column the spinal cord

The answer is spinal cord

Its spinal cord

Explanation:

Reflex action is an instantaneous involuntary response to a stimuli. Like when you touch a hot object, instantaneously you move your hand away from the heat source, such action is reflex action. It happens suddenly without much thinking. Spinal cord plays a major role in this. Please look at the reflex arc below for further clarification. The path followed by reflex action is called reflex arc.

Stimulus -> sensory receptor -> sensory neuron -> relay neuron (in spinal cord) -> motor neuron -> effector -> response

the way that the mass of carbon can be conserved through cellular respiration is through a process/law called the law of conservation of mass which even tho it undergoes a process, mass is not be destroyed or changed