| A | B |
|---|
| nervous system | structures that control the actions of the body in response to stimuli |
| neuron | nerve cell |
| dendrite | part of a neuron that receives stimuli |
| axon | part of neuron that carries impulses away from the cell body |
| action potential | sudden change in the polarity of a neuron that helps transmit electrical impulses |
| myelin sheath | insulation around an axon made of lipids |
| synaptic cleft | gap between neurons |
| neurotransmitter | chemical that transmits nerve impulses across a synapse |
| resting potential | electric charge across a neuon's cell membrane when not active |
| central nervous system | brain and spinal cord |
| peripheral nervous system | all parts of nervous system except brain and spinal cord |
| cerebrum | largest portion of human brain, controls movement |
| cerebral cortex | outer portion of cerebrum that controls higher mental functions |
| brainstem | connects brain to spinal cord |
| thalamus | directs incoming sensory signals to proper region of brain |
| hypothalamus | coordinates activites of nervous and endocrine systems; helps maintain homeostasis |
| medulla oblongata | part of brain stem that controls respiration, circulation, etc. |
| cerebellum | back portion of brain that coordinates muscle movement |
| nerve | bundled axons and dendrites outside CNS |
| sensory receptor | neurons that can detect heat, light, pressure; carry information to CNS |
| motor neuron | nerve cell that carries impulses from CNS to muscles and glands |
| interneuron | nerve cell that relays info. between other nerve cells |
| somatic nervous system | division of PNS that controls skeletal muscles/voluntary movement |
| reflex | involuntary response to a stimulus; often self-protective |
| autonomic nervous system | part of PNS that controls involuntary actions like digestion |
