Final answer:
The condition in which a skeletal muscle cell contracts continuously without relaxation due to rapid, successive stimuli is known as complete tetanus.
Step-by-step explanation:
When a laboratory skeletal muscle cell receives quickly fired multiple, continuous stimuli, which cause the muscle to contract without any period of relaxation, this is known as complete tetanus. In this state, the frequency of action potentials from the motor neuron is so high that the relaxation phase of muscle contraction is eliminated, causing the contractions to become continuous. This is contrasted with incomplete tetanus, where there is still a short relaxation phase between contractions.