Across
- 3. a neurotransmitter that affects mood, hunger, sleep, and arousal. An undersupply is linked to depression.
- 4. chemical messengers that cross the synaptic gaps between neurons
- 6. a major excitatory neurotransmitter, involved in memory
- 8. the part of the peripheral nervous system that controls the glands and the muscles of the internal organs
- 12. a simple, automatic response to a sensory stimulus, such as the knee-jerk response
- 13. foreign substance that blocks certain neurotransmitters, not allowing them to do their job
- 14. the level of stimulation required to trigger a neural impulse
- 17. the body's speedy, electrochemical communication network
- 20. a major inhibitory neurotransmitter. Undersupply is linked to seizures, tremors, and insomnia
- 22. the brain and the spinal cord
- 27. cells in the nervous system that support, nourish, and protect neurons
- 29. the body's "slow"chemical communication system; a set of glands that secrete hormones in the bloodstream
- 30. a neurotransmitter that enables muscle action, learning and memory
- 31. neurons will only fire at full power, either all the way or not at all
- 32. a neurotransmitter that helps control alertness and arousal
- 33. the division of the peripheral nervous system that controls the body's skeletal muscles
Down
- 1. a neural impulse; a brief electrical charge that travels down the axon
- 2. the endocrine system's most influential gland
- 5. the division of the autonomic nervous system that calms the body, conserving its energy
- 7. a neurotransmitter's reabsorption by the sending neuron
- 9. the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
- 10. a neurotransmitter that influences movement, learning, attention, and emotion
- 11. natural, opiatelike neurotransmitter linked to pain control and to pleasure
- 15. the sensory and motor neurons that connect the central nervous system to the rest of the body
- 16. the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations; prepares the body for fight or flight response
- 18. a neuron's resting period after firing, when it recharges and can not fire again until recharged
- 19. the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
- 21. foreign substance that mimics certain neurotransmitters, having similar effects
- 23. part of a neuron that contains the nucleus
- 24. the bushy, branching extensions of a neuron that receive messages and conduct impulses toward toward the cell body
- 25. chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
- 26. a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next
- 28. a nerve cell; the basic building block of the nervous system
- 30. secrets hormones that help arouse the body in times of stress