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Neurobiology2
Vocabulary and Other Stuff
Question | Answer |
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Neurotransmitters | Chemical messengers that traverse the synpatic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, influencing whether it will generate an impulse |
Hormones | Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another |
Dendrites | The bushy, branhing extensions of a neuron that receive messages and conduct impulses toward the cell body |
Endorphins | "Morphine within"--natural, opiate-like neurotransmitters linked to pain control and to pleasure |
Neurons | A nerve cell; the basic building block of the nervous system |
Glial Cells | Cells in the nervous system that are not neurons but that support, nourish, and protect neurons |
Endocrine Glands | The body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream |
Axons | The extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands |
Synapse | The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or cleft |
Reuptake | The reabsorption of a neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron after it has performed its function of transmitting a neural impulse |
Threshold | The level of stimulation required to trigger a neural impulse |
Action Potential | A neural impulse; a brief electrical charge that travels down an axon. Generated by the movement of positively charged atoms in and out of channels in the axon's membrane |
Myelin Sheath | 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 |
Cell Body | The central part of a neuron that includes the nucleus but not the axons or the dendrites |
Synaptic Vesicle | A small membrane-bound structure in the axon terminals of nerve cells that contains neurotransmitters and releases them by exocytosis when an action potential reaches the terminal. |
Refractory Period | A short period after a nerve or muscle cell fires during which the cell cannot respond to additional stimulation. |
Lesion | Tissue destruction. |
Interneuron | Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs |
Affector Neuron (Sensory Neuron) | Neurons that carry incoming information from the sense receptors to the brain |
Effector Neuron (Motor Neuron) | The neurons that carry outgoing information from the central nervous system to the muscles and glands |
PET Scan (positron emission tomography) | A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task |
MRI (Magnetic resonance imaging) | 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 |
Association Area | Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather they are involved in higher mental functions such as learning, remembering, thinking, and speaking |
Depolarization | Loss of the difference in charge between the inside and the outside of the plasma membrane of a muscle or nerve cell due to a change in permeability and the migration of sodium ions to the interior |
Repolarization | The restoration of a polarized state across a membrane |
Reflex | A simple, automatic, inborn response to a sensory stimulus, such as the knee-jerk response |
All-or-none Response | The stimulation has to reach a threshold in order to provoke an action potential. The action potential does not vary in strength according to the strength of the stimulus. |
Acetylcholine | A neurotransmitter that, among its functions, triggers muscle contraction |
Dopamine | A neurotransmitter that regulates movement and emotion |
Serotonin | A neurotransmitter that is involved with sleep, depression, memory, and other neurological processes |
Norepinephrine | A neurotransmitter that has such effects as constricting blood vessels, dilating bronchi, and raising blood pressure |
GABA | A neurotransmitter that inhibits excitatory responses |
Agonist | A substance that can bind with a cell receptor to produce a reaction typical for that substance |
Antagonist | A chemical substance that interferes with the physiological action of another, especially by binding with and blocking its nerve receptor. |
Curare | A poison from a spider that relaxes skeletal muscles |
Parkinson's Disease | Caused by a deficiency in dopamine. |
Alzheimer's | Caused by a deficiency in Acetylcholine. |
Schizophrenia | Caused by an increase in dopamine. |
Depression | Caused by decreased dopamine, decreased serotonin, or decreased norepinephrine |
Autonomic Nervous System | The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic divison arouses; its parasympathetic divison calms. |
Somatic Nervous System | The division of the peripheral nervous system that controls the body's skeletal muscles |
Parasympathetic Nervous System | The division of the autonomic nervous system that calms the body, conserving its energy |
Sympathetic Nervous System | The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations |
Central Nervous System | The brain and spinal cord |
Peripheral Nervous System | The sensory and motor neurons that connect the CNS to the rest of the body |
Limbic System | A doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex. |
Amygdala | Two almond-shaped neural clusters that are components of the limbic system and are linked to emotion |
Hypothalamus | A neural structure lying below the thalamus; it directs several maintenance activities, helps govern the endocrine system via the pituitary gland, and is linked to emotion |
Cerebellum | The "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance |
Thalamus | The brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla |
Reticular formation | A nerve network in the brainstem that plays an important role in controlling arousal |
Medulla | the base of the brainstem; controls heartbeat and breathing |
Frontal Lobe | The portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments |
Parietal Lobe | The portion of the cerebral cortex lying at the top of the head and toward the rear; includes the sensory cortex |
Temporal Lobe | The portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each of which receives auditory information primarily from the opposite ear |
Occipital Lobe | The portion of the cerebral cortex lying at the back of the head; includes the visual areas, which receive information from the opposite visual field |
Sensory Cortex | The area at the front of the parietal lobes that registers and processes body sensations |
Motor Cortex | An area at the rear of the frontal lobes that controls voluntary movements |
Wernicke's Area | A brain area involved in language comprehension and expression; usually in the left temporal lobe |
Broca's Area | An area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech |
Corpus Callosum | The large band of neural fibers connecting the two brain hemispheres and carrying messages between them |
Hippocampus | A neural center located in the limbic system that helps process explicit memories for storage |
Auditory Cortex | The auditory area in the cerebral cortex |
Visual Cortex | The visual area in the cerebral cortex |
Aphasia | Impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding) |
Plasticity | The brain's capacity for modification, as evident in brain reorganization following damage (especially in children) and in experiments on the effects of experience on brain development |