Sherrill AP Biology Chapter 48 Nervous System
Terms : Hide Images
| 681418658 | Actylcholine | One of the most common neurotransmitters; can be inhibitory or excitatory. | |
| 681418659 | Axon | A long extension of a neuron that carries nerve impulses away from the cell body toward target cells. |  |
| 681418660 | Axon hillock | The conical region of a neuron's axon where it joins the cell body; typically the region where action potentials are generated. |  |
| 681418662 | Brain | Organ of the central nervous system where information is processed and integrated. | |
| 681418663 | Cell body | The part of a neuron that houses the nucleus and most other organelles. |  |
| 681418664 | depolarization | A change in a cell's membrane potential such that the inside of the membrane is made less negative relative to the outside. For example, a neuron membrane is depolarized if a stimulus decreases its voltage from the resting potential of -70 mV in the direction of zero voltage. |  |
| 681418665 | Dopamine | A neurotransmitter that is a catecholamine, like epinephrine and norepinephrine. Can affect sleep, mood, attention, and learning. | |
| 681418666 | Endorphine | Any of several hormones produced in the brain and anterior pituitary that inhibits pain perception. | |
| 681418667 | Epinephrine | A catecholamine that, when secreted as a hormone by the adrenal medulla, mediates "fight-or-flight" responses to short-term stresses; also released by some neurons as a neurotransmitter; also known as adrenaline. | |
| 681418668 | Excitatory postsynaptic potential (EPSP) | An electrical change (depolarization) in the membrane of a postsynaptic cell caused by the binding of an excitatory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more likely for a postsynaptic cell to generate an action potential. | |
| 681418669 | Gamma aminobutyric acid (GABA) | An amino acid that functions as a inhibitory CNS neurotransmitter in the central nervous system of vertebrates. | |
| 681418670 | Ganglion | A cluster (functional group) of nerve cell bodies in a centralized nervous system. | |
| 681418671 | Gated ion channel | A gated channel for a specific ion. The opening or closing of such channels may alter a cell's membrane potential. |  |
| 681418672 | Glia | Supporting cells that are essential for the structural integrity of the nervous system and for the normal functioning of neurons. |  |
| 681418674 | Hyperpolarization | A change in a cell's membrane potential such that the inside of the membrane becomes more negative relative to the outside. Hyperpolarization reduces the chance that a neuron will transmit a nerve impulse. Same as repolarization | |
| 681418675 | Inhibitory postsynaptic potential (IPSP) | An electrical change (usually hyperpolarization) in the membrane of a postsynaptic neuron caused by the binding of an inhibitory neurotransmitter from a presynaptic cell to a postsynaptic receptor; makes it more difficult for a postsynaptic neuron to generate an action potential. | |
| 681418676 | interneuron | An association neuron; a nerve cell within the central nervous system that forms synapses with sensory and/or motor neurons and integrates sensory input and motor output. |  |
| 681418678 | membrane potential | The difference in electrical charge (voltage) across a cell's plasma membrane due to the differential distribution of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances. |  |
| 681418679 | motor neuron | A nerve cell that transmits signals from the brain or spinal cord to muscles or glands. |  |
| 681418680 | myelin sheath | Around the axon of a neuron, an insulating coat of cell membranes from Schwann cells or oligodendrocytes. It is interrupted by nodes of Ranvier, where action potentials are generated. |  |
| 681418681 | neuron | A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane. |  |
| 681418683 | neurotransmitter | A molecule that is released from the synaptic terminal of a neuron at a chemical synapse, diffuses across the synaptic cleft, and binds to the postsynaptic cell, triggering a response. |  |
| 681418684 | Nitric Oxide (NO) | A gas produced by many types of cells that functions as a local regulator and as a neurotransmitter. | |
| 681418685 | Nodes of Ranvier | Gap in the myelin sheath of certain axons where an action potential may be generated. |  |
| 681418686 | Norepinephrine | A catecholamine that is chemically and functionally similar to epinephrine and acts as a hormone or neurotransmitter; also known as noradrenaline. | |
| 681418687 | oliodendrocyte | A type of glial cell that forms insulating myelin sheaths around the axons of neurons in the central nervous system. |  |
| 681418688 | Peripheral Nervous System (PNS) | The sensory and motor neurons that connect to the central nervous system. |  |
| 681418689 | Postsynaptic cell | The target cell at a synapse. |  |
| 681418690 | Presynaptic cell | The transmitting cell at a synapse. | |
| 681418691 | refractory period | The short time immediately after an action potential in which the neuron cannot respond to another stimulus, owing to the inactivation of voltage-gated sodium channels. |  |
| 681418692 | Resting Potential | The membrane potential characteristic of a nonconducting excitable cell, with the inside of the cell more negative than the outside. | |
| 681418693 | Saltatory conduction | Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane. |  |
| 681418694 | Schwann cell | A type of glial cell that forms insulating myelin sheaths around the axons of neurons in the peripheral nervous system. |  |
| 681418695 | Sensory neuron | A nerve cell that receives information from the internal or external environment and transmits signals to the central nervous system. |  |
| 681418696 | serotonin | A neurotransmitter, synthesized from the amino acid tryptophan, that functions in the central nervous system. Like dopamine, serotonin affects sleep, mood, attention, and learning. | |
| 681418697 | sodium-potassium pump | A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell. |  |
| 681418698 | spatial summation | A phenomenon of neural integration in which the membrane potential of the postsynaptic cell is determined by the combined effect of EPSPs or IPSPs produced nearly simultaneously by different synapses. |  |
| 681418699 | Substance P | A neuropeptide that is a key excitatory neurotransmitter that mediates the perception of pain. | |
| 681418700 | Synapse | The junction where one neuron communicates with another cell across a narrow gap. Neurotransmitter molecules released by the neuron diffuse across the synapse, relaying messages to the other cell. |  |
| 681418701 | Synaptic Cleft | A narrow gap separating the synaptic terminal of a transmitting neuron from a receiving neuron or an effector cell. |  |
| 681418702 | Synaptic terminal | A bulb at the end of an axon in which neurotransmitter molecules are stored and from which they are released. |  |
| 681418703 | Synaptic vesicle | Membranous sac containing neurotransmitter molecules at the tip of an axon. |  |
| 681418704 | Temporal summation | A phenomenon of neural integration in which the membrane potential of the postsynaptic cell in a chemical synapse is determined by the combined effect of EPSPs or IPSPs produced in rapid succession. |  |
| 681418705 | Threshold | The potential that an excitable cell membrane must reach for an action potential to be initiated. |  |
| 681418706 | Voltage-gated ion channel | A specialized ion channel that opens or closes in response to changes in membrane potential. |  |
