| A | B |
|---|
| Central nervous system (CNS) | the part of the nervous system that consists of the brain and spinal cord |
| Spinal cord | the bundle of nerves within the spine that runs down the length of the back and transmits most messages back and forth between the body and brain |
| Peripheral nervous system (PNS)- | a network of nerves branching out from the spinal cord that conduct information from the bodily organs to the central nervous system and take information back to the organs |
| neurons | , thin cells that constitute the structural and functional unit of nerve tissue along which messages travel to and from the brain |
| synapse | the gap that exists between the axon terminals of the sending neuron and the dendrites of the receiving neuron |
| neurotransmitters | the chemicals released by neurons, which determine the rate at which other neurons fire |
| somatic nervous syster (SNS) | the division of the peripheral nervous system that controls voluntary movement of skeletal muscles |
| Autonomic nervous system (ANS) | the portion of the peripheral nervous system that controls internal biological functions such as heart rate, breathing, and blood pressure |
| Hindbrain | the part of the brain located at the rear base of the skull that is involved in the basic processes of life such as sleeping, walking, coordinating body movements, and regulating vital reflexes |
| midbrain | the smallest division of the brain above the pons that integrates sensory information and relays it upward |
| forebrain | the largest part of the brain that covers the brain’s central core, consisting of left and right hemispheres, which are connected by a wide band of fibers, the corpus callosum |
| lobes | regions into which the cerebral cortex is divided |
| Electroencephalograph (EEG) | a machine used to record the electrical activity of large portions of the brain |
| Computerized axial tomography (CAT) | an imaging technique in which low levels of X rays are passed through the brain, and a computer measures the amount of radiation absorbed by the brain cells and produces a relatively good image of the brain |
| Magnetic resonance imaging (MRI) | an imaging technique that passes nonharmful frequencies through the brain; a computer measures the interaction with brain cells and transforms this interaction into an incredibly detailed image of the brain |
| endocrine system | a chemical communication system located through out the body that uses hormones to send messages through the bloodstream to particular organs of the body |
| hormones | chemical substances produced by the endocrine glands that carry messages through the body in blood and regulate specific body functions |
| pituitary gland | the center of control of the endocrine system that hangs directly below the hypothalamus and secretes a large number of hormones |
| heredity | the genetic transmission of characteristics from parents to their offspring |
| identical twins | twins who develop from one fertilized egg; twins having the same heredity and genes |
| genes | basic building blocks of heredity |
| fraternal twins | twins who come from two different eggs fertilized by two different sperm |
| Positron emission tomography (PET) | an imaging technique used to see which areas of the brain are being activated while performing tasks |
