Across
- 1. A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure.
- 6. the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.
- 8. chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
- 9. neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.
- 10. a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain.
- 12. a period of inactivity after a neuron has fired.
- 16. the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
- 18. the division of the peripheral nervous system that controls the body's skeletal muscles.
- 20. the sensory and motor neurons that connect the central nervous system to the rest of the body.
- 21. the level of stimulation required to trigger a neural impulse.
- 24. a neural impulse; a brief electrical charge that travels down an axon.
- 28. psychology the scientific study of the links between biological and psychological processes.
- 30. a neuron's reaction of either firing (with a full-strength response) or not firing.
- 31. a molecule that, by binding to a receptor site, inhibits or blocks a response.
- 33. "morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.
- 34. the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
- 35. a simple, automatic response to a sensory stimulus, such as the knee-jerk response.
- 36. a molecule that, by binding to a receptor site, stimulates a response.
Down
- 2. a nerve cell; the basic building block of the nervous system.
- 3. neurons that carry incoming information from the sensory receptors to the brain and spinal cord.
- 4. tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.
- 5. a neurotransmitter's reabsorption by the sending neuron.
- 7. a neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body.
- 11. An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.
- 13. the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
- 14. the division of the autonomic nervous system that calms the body, conserving its energy.
- 15. a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.
- 17. a series of x-ray images are taken from different angles and combined by computer into a composite representation of a slice of the brain's structure. Also called a CAT scan.
- 19. the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
- 22. the brain and spinal cord.
- 23. neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
- 25. The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
- 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.
- 27. chemical messengers that cross the synaptic gaps between neurons.
- 29. a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
- 30. the neuron extension that passes messages through its branches to other neurons or to muscles or glands.
- 32. bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs.