The central nervous system consists of the brain and the spinal chord. It is reponsible for the control of thought processes, movements, and provides sensation throughout the body.
The peripheral nervous system The peripheral nervous system includes all the nerves in the body that lie outside of the spinal cord and brain. These nerves carry information to and from the central nervous system to provide complex body functions. Sensory cells are involved in taking information from the periphery to the central nervous system.
The somatic nervous system is the part of the peripheral nervous system associated with skeletal muscle voluntary control of body movements. The somatic nervous system consists of sensory and motor nerves.
The autonomic nervous system is the part of the nervous system that supplies the internal organs, including the blood vessels, stomach, intestine, liver, kidneys, bladder, genitals, lungs, pupils, heart, and sweat, salivary, and digestive glands. The autonomic nervous system has two main divisions the parasympathetic, which is part of the automatic nervous system that counterbalances the action of the sympathetic nerves. It consists of nerves arising from the brain and the lower end of the spinal cord and supplying the internal organs, blood vessels, and glands and sympathetic, which is part of the autonomic nervous system that functions to regulate the body's unconscious actions.
Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.
An interneuron is a neuron that transmits impulses between other neurons, especially as part of a reflex arc.
A motor neuron is a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.
A neuromuscular junction is a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction.
Acetylcholine is an organic chemical that functions in the brain and body of many types of animals, including humans, as a neurotransmitter—a chemical released by nerve cells to send signals to other cells.
Norepinephrine is a hormone that is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter and epinephrine is another term for adrenaline.
Synapse is a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
White matter is the paler tissue of the brain and spinal cord, consisting mainly of nerve fibers with their myelin sheaths.
Gray matter is the darker tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and branching dendrites.
The cerebral cortex is the outer layer of the cerebrum (the cerebral cortex ), composed of folded gray matter and playing an important role in consciousness. The lobes of the brain are the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe.
The primary structures within the limbic system include the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus. The amygdala is the emotion center of the brain, while the hippocampus plays an essential role in the formation of new memories about past experiences.