Final answer:
The myelin sheath is responsible for speeding up the transmission of electrical impulses along the axon, which is essential for efficient communication between neurons. Synaptic vesicles release neurotransmitters into the synaptic cleft, but it is the myelin sheath that accelerates the signal transmission down the axon.
Step-by-step explanation:
One purpose of the myelin sheath is to speed up the neural message traveling down the axon. Synaptic vesicles, located in the axon terminal, contain neurotransmitters which are released into the synaptic cleft, facilitating the communication between neurons. The myelin sheath, however, consists of layers of fatty tissue that insulate the axon and allow the electrical impulses to move more quickly and efficiently along the neural pathway.
In healthy individuals, the neuronal signal travels rapidly down the axon, relayed by the myelin sheath to the terminal buttons, where synaptic vesicles then release neurotransmitters. Once these neurotransmitters are released, they cross the synaptic cleft and bind to receptors on the postsynaptic neuron's dendrite, initiating a new electrical impulse. This efficient transmission is crucial for functions such as reflexes, motor coordination, and sensory processing, emphasizing the importance of the myelin sheath in neural communication.