| Term | Definition |
| Axon | processes that carry information away from the cell body |
| Myelin | a white insulating sheath around some nerve fibers that increases the speed of the impulse |
| cell body | the part of the neuron with the nucleus and metabolic machinery (like mitochondria) |
| dendrites | process that carry information to the cell body |
| axon terminals | the ends of the axon that produce and release the neurotransmitters |
| motor neuron | a neuron that carries impulses from the brain or spinal cord to a muscle or gland |
| sensory neuron | a neuron that carries impulses from a receptor to the brain or spinal cord. |
| interneuron | a neuron that transmits impulses between other neurons |
| Central nervous system | the brain and spinal cord |
| peripheral nervous system | the cranial and peripheral nerves including motor and sensory neurons. Two divisions: motor and sensory |
| afferent division | Sensory input |
| efferent division | motor output |
| reflex arc | simple, automatic response |
| neurotransmitter | chemical signals such as acetylcholine and epinephrine |
| synapse | gap between a neuron and another cell through which information is passed |
| 5 components of reflex arc | stimulus, sensory (afferent) neuron, interneuron, motor (efferent) neuron, effector |
| Divisions of the motor system | Somatic (voluntary) and Autonomic (involuntary) |
| Somatic motor division | Motor neurons innervating skeletal muscle |
| Autonomic division | Motor neurons innervating glands, cardiac and smooth muscle. Contains the sympathetic and parasympathetic divisions |
| Sympathetic nervous system | Part of the autonomic nervous system that prepares the body for flight/flight or action by accelerating heart rate, increasing breathing etc. |
| Parasympathetic nervous system | part of the autonomic nervous system that conserves energy and is active during "rest and digest". Slows heart, constricts pupils but increases digestive activity. |
| Fight or flight response | a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival that activates the sympathetic nervous system. |
| integration | combining information from different sources (visual, touch, olfactory etc) in the CNS. Information processing. |
| Functional classification of neurons | Classification by "job". Sensory, motor and interneurons. |
| Structural classification of neurons | Classification by structures such as # of dendrites or axons. Examples include multipolar and pseudounipolar |
| Schwann cell | A neuroglial cell that wraps around axons creating myelination. This results in faster transmission of impulse. Myelinated axons are "white" matter in the CNS. |
| Neuroglandular junction | a synapse between a neuron and gland tissue |
| Neuromuscular junction | a synapse between a neuron and muscle tissue |
| Ion gradient | difference in ion concentration and electrical potential from one point to another, so that ions tend to move passively along it, usually across a membrane. |
| Resting membrane potential | the difference in voltage of the fluids inside a cell and outside a cell, which is usually between -70 to -80 millivolts (mV). |
| Voltage gated channel | ion channels in the membrane that are activated (opened) by changes in electrical membrane potential near the channel. |
| Depolarization | a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge |
| Repolarization | a change within the cell during which the cell returns to a negative state usually about -70 mv. |
| Hyperpolarization | a change in a cell's membrane potential that makes it more negative. It is the opposite of depolarization. |
| Action Potential | brief (about one-thousandth of a second) reversal of electric polarization of the membrane of a nerve cell (neuron) or muscle cell while a nerve impulse travels along the cell |
| Refractory period | a period immediately following stimulation during which a nerve or muscle is unresponsive to further stimulation |
| Threshold | the magnitude or intensity of a stimulus that must be exceeded for an action potential to occur. Usually about -55 mv |
| Parts of the brain | cerebrum, cerebellum, diencephalon, brain stem |
| Protections of the brain | cranium, meninges, cerebral spinal fluid |
| Meninges | membranes covering the brain that have blood vessels and CSF and serve to protect the brain. Pia mater, arachnoid and dura mater |
| Order of meninges outside to in | Dura, arachnoid, pia |
| CSF | cerebral spinal fluid produced in the brain from blood. Provides shock absorption, nutrients and waste removal. |
