Dissection reveals that the brain is made up of many anatomically distinct areas composed of clusters of neuron cell bodies interspersed by bundles of myelinated axons and pathways between those clusters. These clusters of neuron cell bodies are referred to as

White matter

Explanation:

Brain work like a computer. It is easier to understand the brain. White matter is the substance that connects all the matter and transmits the message. This is the nerve tissue in the brain that contains nerve fibers. The fibers connect the nerve fibers and these nerve fibers are covered by a myelin sheath.  

Myelin sheath help in improving the speed of information from one neuron to another neuron. The myelin speeds up the signal between cells and the signal cells which sends and receives cells.

abu bakr, was a senior companion and—through his daughter aisha—a father-in-law of the islamic prophet muhammad. abu bakr became the first openly declared muslim outside muhammad's family. abu bakr served as a trusted advisor to muhammad.