Acetylcholine is located at the neuromuscular junction, and it triggers muscle contraction in the body's cells. This neurotransmitter is most frequently found in neuronal cells in the central nervous system (CNS) and peripheral nervous system (PNS).

Endorphins are a type of neurotransmitters that are closely linked to pleasure and pain centers in the body. They are not hormones; hormones are chemical messengers that are secreted directly into the blood and travel through the body to various organs.

The cerebellum is located near the base of the brain. Its major function is to coordinate movement and preserve balance. Damage to this area from a stroke will prevent an individual from coordinating their movements.

An MRI is a brain imaging modality that relies on magnetic fields. Strong magnets redirect the electrons within the body to produce an image. MRIs provide useful imaging of the soft tissue structures of the brain, and can be key in finding tumors, bleeding, and other brain abnormalities.

ADHD is a common disorder of childhood that manifests as inattentive behavior and impulsive behavior. Stimulants (such as Ritalin and amphetamines) are the first line treatment for ADHD. Stimulants increase concentration and alleviate symptoms of ADHD for many patients. They work by increasing concentrations of activating neurotransmitters.

Also known as the "starvation hormone", leptin signals the hypothalamus that the body has enough fat stored to function normally. When leptin levels are high enough, appetite is inhibited. When leptin levels are low, it indicates that we need to consume more food and appetite increases.

Cortisol is released by the adrenal cortex, which is controlled by the hypothalamus and anterior pituitary. The hypothalamus releases corticotropin-releasing hormone, triggering the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary gland. ACTH stimulates the release of cortisol. Cortisol is released when the body is under long-term stress, such as malnutrition, dehydration, or prolonged mental stress.

The pineal gland secretes serotonin by day and converts it to melatonin at night. These chemicals affect mood, anxiety, and sleep. The pineal gland may also play a role in seasonal affective disorder, in which people are depressed during the darker days of winter. Selective serotonin reuptake inhibitors (SSRIs) are a class of drug that work to elevate mood by blocking the cells that breakdown serotonin, leaving it in the synapses of the nervous system for a longer period of time.

Dopamine has a neuromuscular function, as an absence is associated with Parkinson's disease. Norepinephrine has a stimulatory effect. Acetylcholine stimulates muscle cells to contract. Endorphins are the body's natural pain relievers. 

Epinephrine, also called adrenaline, is a hormone that activates the sympathetic nervous system. This triggers our "fight or flight" response, which increases heart rate, dilates the pupil, increases blood flow to skeletal muscle, and reduces digestive and reproductive activity.

The pituitary gland is considered the "master gland" of the endocrine system. Hormones secreted from the pituitary gland help regulate growth, metabolism, and numerous other bodily functions and processes. The medulla oblongata is the part of the brainstem located just above the spinal chord.