| A | B |
|---|
| Soma | Cell body |
| Myelin Sheath | Fatty layer that covers some axons to allow faster transfer of charge |
| Synaptyic Vesicles | Membranous cytoplasmic sacs formed by enfolding of cell membrane in synapse. Contain neurotransmitters. |
| Resting Potential | Electrical charge of a neuron at rest (-70mv) |
| Sodium-Potassium Pump | A system that moves positively charged sodium ions and negatively charged potassium ions in and out of an axon to move the action potential forward |
| Absolute Threshold | Absolute minimum amount of energy necessary for a sensation to occur |
| Excitatory Signals | Signals that move the next neuron closer to firing |
| Sensory Neuron | A nerve cell that carries messages form the senses to the CNS |
| Motor Neuron | Cell that carries commands form the CNS to muscles and glands |
| Interneuron (connector neuron) | A nerve cell that links two others |
| Axon | Carries information away from the cell body |
| Nodes of Ranvier | Narrow gaps in myelin sheath |
| Synaptic Knob | Tiny enlargement at the end of an axon that secretes a neurotransmitter |
| Action Potential | Nerve impulse (+30mv) |
| Depolarization | Loss of negative electrical charge from inner membrane surface |
| Refractory Period | Brief period immediately following the response especially of a muscle or nerve before it recovers the capacity to make a second response |
| Synapse | Microscopic space between two neurons, over which messages pass |
| Antagonist | Muscle that opposes prime mover |
| Dendrite | Specialize in receiving messages form other neurons |
| Synaptic Terminals | The axon terminal at the synaptic gap that donates neurotransmitters to the next neuron |
| Nucleus | Cellular organelle enclosed by double-layered, porous membrane and containing DNA |
| Selectively permeable | Describes membrane that allows some molecules through but not others |
| Hyperpolarization | To undergo or produce an increase in potential difference across something |
| All-or-none response | An impulse occurs completely or not at all |
| Neurotransmitter | Chemical that alters activity in other neurons |
| Glial Cell | Cell that makes up a delicate network of fibers that supports the CNS |
| Central Nervous System | Consists of brain and spinal cord (voluntary) |
| Peripheral Nervous System | Composed of nerves that carry information to and from the CNS (involuntary) |
| Autonomic System | Serves the internal organs and glands of the body (part of PNS) |
| Sympathetic Branch | Emergency system that prepares the body for "fight or flight" during times of danger or emotion (part of ANS) |
| Parasympathetic Branch | Quiets body and returns it to a lower level of arousal (part of ANS) |
| Brain Stem | Lowest portions of the brain, includes: cerebellum, medulla, and reticular formation |
| Cerebrum | Two large hemispheres that cover the upper part of the brain |
| Cerebral Cortex | Outer layer of tissue that forms the outer layer and surface of the cerebrum |
| Cerebellum | At the base of the brain that controls posture and coordination |
| Forebrain | Highest brain areas:Hypothalamus,corpus callosum,thalamus,and cerebrum |
| Occipital Lobes | Primary visual area of cortex |
| Parietal Lobes | Bodily Sensations that are registered |
| Temporal Lobes | Auditory information |
| Frontal Lobes | Association of higher mental functions and control of movements |
| Broca's Area | Aphasia, found on left frontal lobe |
| Wernicke's Area | Aphasia, found on the left temporal lobe |
| Medulla | Contains centers important for the reflex control of vital life functions |
| Reticular Formation | Influences messages entering and leaving the brain: association of attention, movement, and alertness |
| Limbic System | Has a major rule role in producing emotion and motivated behavior |
| Hypothalamus | Master control center for emotion and many basic motives |
| Endocrine System | glands that pour chemicals directly into the bloodstream or lymph system |
| Inhibitory signals | Signals that prevent the next neuron from firing |
| CAT scan | A cross-sectional view of an internal body structure using computerized axial tomography |
| EEG | Electroencephalograph; a machine that records the electrical potentials created by the brain while a person sleeps |
| Pet Scan | Positron emission tomography; a computer-generated image of brain activity, based on glucose consumption in the brain |
| "Split-brain" operation | a rare surgery in which the corpus callosum is cut to control severe epilepsy |
| Functions of Left Brain | Speaking, writing, understanding language, Calculation, rhythm |
| Functions of Right Brain | Perceptual skills, such as recognizing patterns, faces, and melodies; visualization; spatial skills |
| Neglect | A problem in which patients pay no attention to one side of visual space |
| Agnosia | an inability to identify seen objects |
| Plasticity | A flexibility in brain organization |
| Redundancy | refers to the brain's tendency to use several areas to accomplish what just one area alone could do |
| Hormone | chemicals that affect internal activities and behavior |
| Corticalization | increase in the size and wrinkling of the cortex |
| Laterization | specialization in the ability of the brain hemispheres |
| Adrenal Cortex | outer "bark" of the adrenal glands, produces a set of hormones called corticoids |
| Midbrain | link between the forebrain and the brainstem |
| Subcortex | lies below the cerebral cortex |
