Biology 621A - Chapter 12 - Nervous System (Sec 12.1/12.2)
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35 terms
Terms | Definitions |
|---|---|
 neuron | a nerve cell; the basic building block of the nervous system. |
| brain | specialized group of nerve cells that controls & coordinates activities of the nervous system |
| cns | the portion of the vertebrate nervous system consisting of the brain and spinal cord |
| pns | subdivision of the nervous system that brings information to the cns |
| autonomic nerves | serves the internal organs of the body |
| nerve impulse | message that travels from the dendrites of a neuron to the axon |
| axon | long nerve fiber that conducts away from the cell body of the neuron |
| dendrite | the branching extensions of a neuron that receives messages and conducts impulses toward the cell body |
| schwann cell | large nucleated cells that form myelin around the axons of neurons |
| node of ranvier | small gap between myelinated segments where axonal membrane is exposed; increase speed of impulses |
| synapse | the space between two neurons through which neurotransmiters travel |
| receptor | recieves information about changes in the enviroment (stimuli) |
| effector | muscles or glands that respond to impulses |
| stimulus | something that causes a response |
| cell body | contains major concentration of the cytoplasm and the nucleus of the neuron |
| myelin | an electrically-insulating phospholipid (fat) layer that surrounds the axons of many neurons |
| reflex | A relatively simple, involuntary response to a stimulus. |
| resting potential | the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse |
| action potential | change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated |
| refractory period | the time after a neuron fires during which a stimulus will not evoke a response |
| saltatory conduction | transmission of an impulse by jumping |
| neurotransmitter | a chemical messenger that travels across the synapse from one neuron to the next and influences whether a neuron will generate an action potential(impulse) |
| spinal cord | part of central nervous system, links brain to rest of body |
| cerebellum | responsible for balance and coordination, routine movement |
| cerebrum | the largest part of the brain, controls thinking, reasoning, and memory |
| corpus callosum | connects the hemispheres; found deep inside cerebrum; allows hemispheres to share information |
| pons | relay link between brain and spinal cord |
| medulla oblongata | Regulates ♥ heart rhythm, blood flow, breathing rate,etc. |
| endorphins | natural neurotransmitters linked to pain control |
| sclera | Tough, white outer layer of the eye |
| autonomic nervous system | The part of the nervous system that controls involuntary action and responses. |
| Parkinson's Disease | a progressive disease that destroys brain cells and is identified by muscular tremors, slowing of movement, and partial facial paralysis |
| Alzheimer's Disease | a disease that results in the progressive loss of an individual's memory and mental capacity. |
| ALS | "Lou Gherig's Disease" - progressive neurological disease in which the motor neurons degenerate to the point of total loss of motor function. The intelligence, memory, and personality is unaffected. |
| Multiple Sclerosis | disorder in which myelin is destroyed causing loss of motor activity |
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