Central Nervous System: CNS; the complex nerve tissues that controls the activities of the body. It consists of the brain and spinal cord. One of the main parts of the Nervous System.
Peripheral Nervous System: the Nervous System which is outside of the brain and spinal cord. The PNS controls your muscles and joints, as well as sending all the information from your senses back to your brain.
Somatic Nervous System: or voluntary nervous system; the part of the peripheral nervous system associated with skeletal muscle voluntary control of body movements. The SoNS consists of afferent nerves or sensory nerves, and efferent nerves or motor nerves.
Autonomic Nervous System: the part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
Parasympathetic Nervous System: one of three divisions of the autonomic nervous system. Sometimes called the rest and digest system, the parasympathetic system conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.
Sympathetic Nervous System: the part of the autonomic nervous system that contains chiefly adrenergic fibers and tends to depress secretion, decrease the tone and contractility of smooth muscle, and increase heart rate — compare parasympathetic nervous system.
Sensory Neuron: a nerve cell that conducts impulses from a sense organ to the central nervous system.
Interneuron: a neuron that transmits impulses between other neurons, especially as part of a reflex arc.
Motor Neuron: a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland.
Neuromuscular Junction: a synapse between a motor neuron and skeletal muscle. This lesson describes the events of synaptic transmission leading to contraction of skeletal muscle. Myasthenia gravis is described as a neuromuscular disease.
Acetylcholine: 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 and Epinephrine: Norepinephrine is a hormone that is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. It is also used as a drug to raise blood pressure. Epinephrine is another term for adrenaline, which is a hormone secreted by the adrenal glands, especially in conditions of stress, increasing rates of blood circulation, breathing, and carbohydrate metabolism and preparing muscles for exertion.
Synapse: a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
White Matter: the paler tissue of the brain and spinal cord, consisting mainly of nerve fibers with their myelin sheaths.
Gray Matter: the darker tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and branching dendrites.
Cerebral Cortex: the outer layer of the cerebrum (the cerebral cortex ), composed of folded gray matter and playing an important role in consciousness.
Lobes of the Brain: 4; The frontal lobe, parietal lobe, occipital lobe, and temporal lobe have been associated with different functions ranging from reasoning to auditory perceptio
Limbic System: a complex system of nerves and networks in the brain, involving several areas near the edge of the cortex concerned with instinct and mood. It controls the basic emotions (fear, pleasure, anger) and drives (hunger, sex, dominance, care of offspring).