The Central Nervous System
the complex of nerve tissues that controls the activities of the body. In vertebrates it comprises the brain and spinal cord.
The Peripheral Nervous System
the nervous system outside the brain and spinal cord.
Somatic Nervous System
The somatic nervous system (voluntary nervous system) is the part of the peripheral nervous system associated with skeletal muscle voluntary control of body movements. It 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. The Sympathetic and Parasympathetic Nervous systems are within this system.
Sympathetic Nervous System
The sympathetic nervous system's primary process is to stimulate the body's fight-or-flight response. It is, however, constantly active at a basic level to maintain homeostasis.
Parasympathetic Nervous 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.
Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.
a neuron that transmits impulses between other neurons, especially as part of a reflex arc.
A motor neuron is a nerve cell whose cell body is located in the spinal cord and whose fiber projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.
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.
Epinephrine and norepinephrine
Epinephrine and norepinephrine are released by the nervous system. They are the flight/fight hormones that are released when the body is under extreme stress. During stress, much of the body's energy is used to combat imminent danger.
a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
White matter is composed of bundles of axons which connect various gray matter areas of the brain to each other, and carry nerve impulses between neurons.
Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil, glial cells, synapses, and capillaries.
the outer layer of the cerebrum composed of folded gray matter and playing an important role in consciousness
Lobes of the Brain
The cerebral cortex is divided into four sections, called "lobes": the frontal lobe, parietal lobe, occipital lobe, and temporal lobe.
The Limbic System
The limbic system supports a variety of functions including emotion, behavior, motivation, and long-term memory. Emotional life is largely housed in the limbic system, and it has a great deal to do with the formation of memories.