Neurons

• Neuron: Cell of the Nervous System which nervous impulses are transmitted.
• Soma: Is the relatively fat central part of the cell between the dendrites and the axon
• Dendrite: A short, branching arbor.
• Axon: May extend up to tens of thousands of time the diameter of the soma in length
• Nervous Impulses: Nervous Impulses enter the neuron through the dendrites and travel to the axon. The axon transmits the impulse to the dendrites of the following neuron, always in the same ongoing direction.
• Afferent neurons: Convey information from tissues and organs into the central nervous system.
• Efferent neurons: Transmit signals from the central nervous system to the effector cells.
• Interneurons: Connect neurons within the central nervous system.

Neurotransmitter

• Neurotransmitter: Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a presynaptic and a postsynaptic neuron.
• Synapse: The point at which the axon of one neuron makes contact with the dendrites of another neuron.
• Acetylcholine: It is particularly important in the stimulation of muscle tissue and memory. Alzheimer's Disease is associated directly with the deterioration of the neurons which produce acetylcholine.
• Dopamine: Dopamine is critical to the way the brain controls our movements and is a crucial part of the basal ganglia motor loop. Shortage of dopamine, causes Parkinson's disease, in which a person loses the ability to execute smooth, controlled movements.
• Noradrenaline: Plays an important role in learning, memory, apetite, and emotions.
• Serotonin: Serotonin is believed to play an important part of the biochemistry of depression, bipolar disorder and anxiety. It is also believed to be influential on sexuality.
• Endorphine: Endorphins regulate feelings of pain and hunger.

Nervous Systems

• Nerve: Any of the cordlike bundles of fibers made up of neurons through which sensory stimuli and motor impulses pass between the brain or other parts of the central nervous system and the eyes, glands, muscles, and other parts of the body. Nerves form a network of pathways for conducting information throughout the body.
• Sympathetic: Responsible for providing responses and energy needed to cope with stressful situations such as fear or extremes of physical activity.
• Parasympathetic: Helps the body the body's need to rest, recover, and gain new energy.
• Spinal Cord: The spinal cord carries sensory signals and motor innervation to most of the skeletal muscles in the body. Just about every voluntary muscle in the body below the head depends on the spinal cord for control.
• The Brain: The brain keeps the body in order. It helps to control all of the body systems and organs, keeping them working like they should. The brain also allows us to think, feel, remember and imagine.