| A | B |
|---|
| regulation | all the activities that help to maintain an organism's homeostasis |
| stimulus | anything that causes a receptor to start impulses in a nerve pathway |
| receptors | sense organs that are sensitive to certain changes inside or outside the organism |
| impulse | message sent throughout an organisms; change in electrical charge between outer and inner surfaces of the nerve cell membrane |
| effector | specialized structure, muscle or gland, that responds to commands of the nervous system |
| response | how an effector acts upon a stimulus |
| sensory neurons | carry impulses from receptors to the spinal cord and brain |
| interneurons | connects motor neurons to sensory neurons |
| motor neurons | carries impulses from the brain and spinal cord to the effectors |
| polarization | difference in charges inside and outside the neuron |
| sodium-potassium pump | active transport mechanism that moves sodium and potassium out of the neuron |
| refractory period | the inability of impulses to be carried in a neuron while it is trying to return to a resting state |
| myelin | surrounds the cells of some neurons; increases rate of impulse conduction |
| Schwann cells | cells that make up some axons of a neuron |
| nodes of Ranvier | gaps in the myelin between Schwann cells that exposes the axon |
| threshold | a nerve's minimum level of sensitivity |
| synapse | gap between an axon of one cell and a dendrite of another |
| synaptic knob | located at the end of an axon |
| synaptic vesicles | located in the synaptic knobs that contain neurotransmitters |
| neurotransmitters | chemicals that are released into the synaptic gap to continue impulses into neighboring nerve cells |
| excitatory neurotransmitters | starts impulses in neighboring neurons |
| inhibitory neurotransmitters | blocks neurotransmitters to be sent to other neurons |
| curare, botulin, toxin | interferes with neurotransmitters at the synapse |
| stimulants, caffeine | speeds neurotransmitters; slow suddenly |
| depressants, alcohol | slows or blocks some neurotransmitters |
| LSD | inhibits transmissions between neurons; causes hallucinations |
| central nervous system | brain and spinal cord |
| meninges | covering and protection of brain and spinal cord |
| cerebrospinal fluid | liquid substance that cushions brain and spinal cord from shock |
| concussion | brain touches skull |
| hypothalamus | controls body temp., blood pressure, sleep, and emotions |
| pons | brain stem part that connects spinal cord and brain |
| cerebrum | largest part of brain; controls sensations, motor skills, and associations |
| cerebral hemisphere | half of the cerebrum; divided by a fissure |
| corpus callosum | connects left side of brain with right side; responsible for crossover |
| gray matter | outermost layer of cerebrum; cell bodies of motor neurons and interneurons |
| white matter | below gray matter made of myelinated nerve fibers |
| cerebellum | below rear of cerebrum; responsible for muslce movement and coordination |
| medulla oblingata | connected to spinal cord; responsible for most involuntary activities |
| peripheral nervous system | neurons and nerve fibers outside of the brain and spinal cord |
| somatic nervous system | PNS; anything under voluntary control |
| autonomic nervous system | PNS; serves internal organs |
| reflex | involuntary automatic response given to a sudden stimulus |
