ANATOMY

Detailed explanation-1: -Peripheral nerves reside outside your brain and spinal cord. They relay information between your brain and the rest of your body.

Detailed explanation-2: -The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

Detailed explanation-3: -The brachial plexus begins in the spinal cord at the cervical and upper thoracic region (from C5-T1) and is a system of nerves that relays messages to and from the central nervous system to your shoulder, arm and hand.

Detailed explanation-4: -In vertebrates, the CNS also includes the retina and the optic nerve (cranial nerve II), as well as the olfactory nerves and olfactory epithelium. As parts of the CNS, they connect directly to brain neurons without intermediate ganglia.

Detailed explanation-5: -Ganglia are clusters of nerve cell bodies present outside the CNS. The nerve cell bodies are clustered together in these structures and their axons reach different parts of the organ.