Definition of each term and their effects Neurotransmitters =They are messengers that take messages across the synapse. =When neurotransmitters get damage, it will cause muscle weakness, a slow reaction time, and even cause a general sense of pain. These are the example of symptoms that Randy is suffering. Hormones =They are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions.=Hormones are the one which can affect weight gain. And this is also another symptom that Randy is suffering.Myelin Sheath =Myelin sheath speeds up communication along the axon. =When myelin sheath is damaged, it can cause motor issues. For example, it slows reaction time causes muscle weakness. Occipital lobe =The Occipital lobe contains the visual cortex. It is the part that helps us to see something. =Since Randy is experiencing illusion, this could be the problem part where the visual perception has an issue.