Term
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Definition
-first neurotransmitter to be identified
-used at neuromuscular junction.
-Its action is terminated by cholinesterase |
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Term
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Definition
| causes paralysis of skeletal muscles (and death from respiratory paralysis) by competing with acetylcholine for binding of the acetylcholine receptor found at the neuromuscular junction. |
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Term
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Definition
| An autoimmune disorder where the patient develops antibodies against their own acetylcholine receptors at the neuromuscular junction (preventing synaptic transmission) |
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Term
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Definition
| Produced by the bacterium Clostridium botulinum. It blocks the actual release of acetylcholine at the neuromuscular junction by preventing synaptic vesicles from fusing with plasma membrane of the presynaptic terminal. The toxin causes fatal paralysis. |
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Term
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Definition
| acts on the central nervous system by preventing the release of the inhibitory neurotransmitter GABA. Its effects are complicated, and lead to severe muscle spasms (tetanic seizures) and possibly death. |
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Term
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Definition
| Neurons that use acetylcholine |
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Term
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Definition
-Norepinephrine
-Dopamine
-Serotonin |
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Term
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Definition
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Term
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Definition
| A catecholamine that is secreted by the adrenal glands. Another name of epinephrine is adrenaline. Epinephrine has actions similar to norepinephrine. Epinephrine is not know to be a neurotransmitter. Rather, it should be regarded as a hormone, since it is carried round the body by the bloodstream. |
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Term
| Reuptake Monoamine oxidase |
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Definition
| Like dopamine, Norepinephrine is removed from the cleft by reuptake methods. It is also terminated by monoamine oxidase. |
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Term
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Definition
| neurons that use norepinephrine as a neurotransmitters. |
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Term
| Dopamine nigrostriatal pathway |
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Definition
| Dopamine-containing neurons are found in midbrain regions, notably the substantia nigra and ventral tegmentum. Neurons in the substantia nigra send axons to the basal ganglia via nigrastrital pathway |
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Term
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Definition
| Dopamine is removed from the synaptic cleft mainly by uptake mechanisms (involving a dopamine transporter molecule) that return it to the cytoplasm of the presynaptic neuron |
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Term
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Definition
| Neurons that use dopamine as a neurotransmitter |
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Term
| Brain Disorders (serotonin) |
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Definition
| has also been implicated in depression, aggressive and impulsive behavior, and in suicidal tendencies. Serotonin seems to be mainly an excitatory neurotransmitter. |
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Term
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Definition
1) Glutamin acid
2) Gamma-aminobytyric acid (GABA) |
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Term
| Glutamic Acid; Asparic Acid |
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Definition
| Glutamic acid is one of the most prevalent excitatory neurotransmitters in the brain, and is found in many neurons (Asparic acid is also used by the brain as an excitatory neurotransmitter). |
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Term
| Cerebrovascular accidents (stroke) overexcited excitoxicity |
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Definition
Glutamic acid may be involved in cell death following a stroke. A stroke occurs when a blood vessel bringing oxygen and nutrients to the brain bursts or is clogged by a blood clot. Lack of blood causes cells to die within minutes. The cells closest to the injury die of oxygen deprication, but it seems that as they die they large quantities of neurotransmitters, particularly glutamic acid, from their endings.
Cells exposed to an overdose of glutamic acid become overexcited, swell and die. This is called excitoxity. Thus a widening area neuronalcell death can develop around the original oxygen-dprived area |
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Term
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Definition
| The destruction of cells following exposure to excess amounts of the excitatory neurotransmitter glutamic acid is called excitotoxicity. drugs that block glutamic acid or combat the excitocity it causes would therapeutically important in limiting cell death |
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Term
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Definition
| Involved in gut relaxation during peristalsis, erection of the penis, vasomotion, - it exists as NO, and NO+. The free radical NO, the reduced form NO, seems to be the the toxic form, because it can react with superorxide anion to form peroxynitrite, the final toxic agent. On the other hand, the nitrosonium ion, NO+ may act beneficially by reacting with the NMDA glutamine receptor and blocking it. |
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Term
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Definition
| Neurons that use glutamate as a neurotransmitter |
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Term
| Gamma-aminobutyric acid (GABA) |
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Definition
| may be the more prevalent inhibitory neurotransmitter in the brain, perhaps being used in one-third of all brain synapses. It is found in some neurons of the basal ganglia, and in certain cell types in the cerebellum as well as in some spinal interneurons. |
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Term
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Definition
| inhibitory amino acid neurotransmitter released by certain spinal interneurons. |
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Term
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Definition
| GABA functions to damp down neuronal chatter, and prevetns chaos in the brain’s system of communication. If levels of GABA are too low; the result may be an epileptic seizure or the development of a state of clinical anxiety resulting from the overactivity of certain neuronal circuits in the brain sometimes too much Glutamic acid can be the cause |
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Term
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Definition
| Loss of GABA-ergic neurons seems to be involved in the early stages of Huntingtons’s disease, a condition where there is excessice involuntary movement. |
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Term
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Definition
-hormones that are released into the blood, and reach their target cells through the circulation.
-Neurotransmitters that change the conductance of the postsynaptic membrane to one or more ions
-Neuromodulators that modulate synaptic transmission, either by affecting the release of another neurotransmitter at the presynaptic ending or by altering the response of the postsynaptic cell. |
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Term
| Opioid neuroactive peptides |
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Definition
| Humans have opiates such as morphine and heroin to deaden pain (produce analgesia) and generate euphoria. The brain synthesizes neuroactive peptides that are very similar to morphine. They are called opiod neuroactive peptides. Opiate receptors are specific proteins on the plasma membranes of neurons. |
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Term
| Three classes of endogenous opioid neuroactive peptides |
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Definition
-Enkephalins
-Endorphins
-Dynotphin |
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Term
| Non-opioid neuroactive peptides; Substance P |
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Definition
| These have their own receptors that do not bind opiates. In the brain, their functions are not alwas well-understood, but many of them also occur in the gastrointestinal tract. One example is cholecystokinin, a hormone secreted by the small intestine A non-opiod neuroactive peptide substance P, which is the suspected neurotransmitter in the pain pathway in the spinal cord. |
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Term
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Definition
| Neurons that use neuroactive peptides as neurotransmitters are called peptidergic |
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Term
| Cocaine; nucleus accumbens |
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Definition
| Crack cocaine enters the bloodstream through the lungs. Within seconds it is carried to the brain where it acts in the limbic system, specificallyon a limbic region called the nucleus accumbens, which is involved in feeling of pleasure and reward. |
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Term
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Definition
| Cocaine exerts its effects at synapses. Normally, a dopaminergic transmitting cell in the limbic system relays a signal by releasing dopamine into the synaptic cleft. To end the signal, dopamine molecules are taken up into the presynaptic terminal to be recycled. Cocaine blocks removal of dopamine from the synaptic cleft. It does this by specifically blocking dopamine transporter. (it also has the same effect on the norepinephrine transporter, an effect that is important when we consider the lethal effects of cocaine on the heart). In consequence, dopamine accumulates progressively. this continuously stimulates the receiciving cell and causes a “high." |
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Term
| Cocaine; serotonin and norepinephrine |
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Definition
| Cocaine also inhibits the reuptake of serotonin and norepinephrine. The action on norepinephrine reuptake affects the heart, and may cause death from heart failure |
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Term
| Brain conditions: Dopamine |
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Definition
| schizophrenia (glutamine may also be involved), Parkinson’s disease |
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Term
| Brain Conditions: Serotonin, Norepinephrine |
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Definition
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Term
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Definition
| Huntington’s chorea, clinical anxiety, some cases of epilepsy |
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Term
| Brain Conditions: Glutamate |
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Definition
| some cases of epilepsy, schizophrenia |
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Term
| Schizophrenia prefontal cortex |
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Definition
| is characterized by marked disturbances in thinking, emotion responses and social behavior. There is a sense of persecution by others, voices are heard and there are sometimes bizarre delusion of grandeur. Connected to prefontal cortex damage. the prefrontal cortex has one of the highest concentrations of nerve fibers using the neurotransmitter dopamine. |
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Term
| The biogenic hypothesis: norepinephrine and serotonin |
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Definition
| the biogenic amine hypothesis of depression suggests that there is diminished activity of norepinephrine and serotonin pathways in the brain. |
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Term
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Definition
| Dopaminergic in the substantia nigra send axons to the basal ganglia. Degeneration of these dopaminergic fibers occurs in Parkinson’s disease. Attempts at curing the condition include injection of L-dopa (a dopamine precursor that can pass from the blood to the brain) and transplantation of fetal brain dopaminergic tissue. |
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Term
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Definition
| In its early stages. Huntington’s chorea is characterized by hyperactivity of movement. Huntington’s patients hace continuous, uncontrollable, yeick movements of the limbs. It is frequently also associated with personality disorder, possibly because of the connection of the basal ganglia to components of the limbic system. A deficit in inhibitory GABA-ergic neurons in parts of the basal ganglia occurs during the early stages of Huntington’s disease |
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Term
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Definition
| GABA is one of the brain’s important inhibitory neurotransmitters. It may serve to “damp-down” certain neural networks and prevent their overactivity. A deficiency of GABA in certain parts of the amygdala, and hence overactivity of neurons in the brain region, has been strongly implicated in at leased some clinical anxiety conditions |
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Term
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Definition
| is a major region of the brain that is concerned with the planning execution and smooth coordination of movements and posture. Diseases of this part of the brain cause marked impairment of motor function. Additional, it is believed that the cerebellum may play important role in the learning of motor skills, such as typing and playing the violin. |
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Term
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Definition
| The cerebellum constitutes about 1/8 of the total mass of the brain. It is separated from the cerebrum by a tranverse fissure and by an extension of the dura mater called the tenrorium cerebelli |
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Term
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Definition
| The cerebellum is shaped rather like a butterfly. There is a central constricted area called the vermis and the two wing called hemispheres. These hemispheres are partially separated by a layer of dura mater called the falx cerebelli. |
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Term
| Cerebellar cortex; Purkinje cells |
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Definition
| Like the cerebrum, the cerebellum is composed mainly of white matter with a thin layer of gray matter, the cerebellar cortex, on its surface. Purkinje cells are the major output cells of the cerebellar cortex, and very prominent in histological sections |
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Term
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Definition
| Beneath the gray matter are white matter tracts that resemble the branches of a tree |
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Term
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Definition
Deep within the white matter are three masses of gray matter called the cerebellar nuclei:
-fastigial nucleus
-interposed nucleus
-dentate nucleus
These nuclei are concerned with conveying information from the cerebellum to onter parts of the nervous system |
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Term
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Definition
| This nucleus is involved in conveying information from the cestibular apparatus of the inner ear to the cerebellum and in coveying commands from the cerebellum to the motor neurons controlling muscles affecting balance and posture. |
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Term
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Definition
| this nuclus plays an important role in motor learning |
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Term
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Definition
The cerebellum is connected to the brain stem by three paired fiber tracts called the cerebellar peduncles:
-inferior cerebellar peduncle- connects with the meddulla
-middle cerebellar peduncle- connects with the pons
-superior cerebellar peduncle- connects with the midbrain |
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Term
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Definition
| Somatic sensory information is provided via the spinocerebellar tracts (or via the cranial nerves) and includes information from muscle spindles, Golgi tendon organ, joint and cutaneous receptors. |
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Term
Input to the cerebellum: balance
uticle, sacule, semicircular canals |
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Definition
| Information important in balance arrices via the vestibular nucleus of cranial nerve VIII from the utricle, saccule and the semicircular canals of the inner ear. |
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Term
| Input to the cerebellum: plans for movement |
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Definition
| Information about plans for movement is relayed to the cerebellum from the cerebral cortex. |
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Term
| Output from the cerebellum |
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Definition
| The cerebellum is concerned with the planning, initiation, timing and execution of movements as well as with balance and eye movements. After being relayed through the cerebellar nuclei (dentate, fastigial, interposed) and the lateral vestibular nucleus found in the medulla, the output from the cerebellum goes to many areas of the brain are involved in movements. |
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Term
| Destination of outputs from the cerebellum |
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Definition
- parts of the cerebral cortex involved in movement (via another relay in the thalamus)
-brain stem
-the red nucleus in the midbrain, the reticular formation
-vestibular nucleus
-the vestibulospinal tracts provide input to spinal motor neurons involved in posture and balance |
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Term
| Functions of the Cerebellum - planning and programming |
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Definition
| With the cerebral cortex, the cerebellum is involved in planning and programming of voluntary movements |
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Term
| Functions of the Cerebellum - Execution |
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Definition
| The cerebellum is involved in the execution of smooth, coordinated voluntary movements. It regulates the rate, range, force, direction and timing of movements by controlling the activities of agonist, antagonist, and synergist muscles. compares intended with actual movements. When the actual movement deviates from that which has been planned, the cerebellum issues compensatory commands via the motor systems. |
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Term
| Function of Cerebellem - posture |
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Definition
| The cerebellum is involved in posture, balance and equilibrium |
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Term
| Functions of the cerebellum - learning |
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Definition
| may have a role learning motor skills |
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Term
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Definition
1)The cerebellum receives information from the cerebral cortex about plans for movement.
2) The cerebellum receives information about motor perfomance- that is, ongoing movements - from sensory feedback.
3) the cerebellum sends its output to the motor systems of the brain |
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Term
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Definition
| receives input from the vestibular apparatus of the inner ear and contols balance and eye movements, coordinating movements of the head and eyes |
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Term
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Definition
| contains topographical maps of the body that receive sensory information from the spinal cord. Pats of it also receive auditory and visual information. The spinocerebellum is mainly concerned with the execution of movements and the regulation of muscle tone. It smoothes out physiological tremors and compensates for variations in muscle loading during movement. |
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Term
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Definition
| receives inpur from wide areas of the cerebral cortex. It does not receive peripheral sensory input. The cerebrocerebellum coordinates the planning of limb movements. |
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Term
| Motor abnormalities: dysmetria |
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Definition
| Cerebellar disease causes motor abnormalities. The coordinated contractions of agonist and antagonist muscles to generate smooth, well-coordinated and well-controlled movement may be destroyed. the result may be dysmetria, or inacurate range and directionof movements, coupled with overshoot or undershoot when reaching for an object |
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Term
| Cerebellar disease effect |
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Definition
| In a normal person, the cerebellum spares us that mental effort. Like an army command center, our cerebral cortex appears to issue general commands for movements, but leaves the specific details for execution of these movements to subcortical, notably cerebellar mechanisms |
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