Neco 2022 Biology Question 38

A motor neuron conducts an impulse from the spinal cord to a skeletal muscle fibre 0.8 m away. The conduction velocity in the myelinated axon is 80 m s\(^{-1}\). The synaptic delay at the neuromuscular junction is 0.5 ms and the muscle contraction latency after depolarisation is 2 ms.\n(a) Calculate the total time from impulse initiation to muscle contraction.\n(b) In a reflex arc, a sensory neuron travels 0.4 m at 50 m s\(^{-1}\), synapses onto an interneuron that travels 0.2 m at 30 m s\(^{-1}\). Both the sensory‑interneuron and interneuron‑motor synapses each incur a 0.5 ms delay. The motor neuron is the same as above, with the same NMJ delay and muscle latency. Calculate the total reflex time and state which pathway is faster and by how many milliseconds.