Term
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Definition
| 0.5 cm thick layer of gray matter composed primarily of neuronal cell bodies, dendrites, and synapses covering the surface of a hemisphere |
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Term
| What are association fibers? |
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Definition
: interconnect various areas within the same hemisphere
short assoc. fibers connect adjacent gyri
long assoc. fibers interconnect distant areas of cortex |
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Term
| What are commissural fibers? |
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Definition
| interconnect corresponding structure on either side of the neuraxis |
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Term
| What is the corpus callosum? |
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Definition
• largest bundle of commissural fibers interconnecting frontal, parietal, and occipital lobes
• consist of rostrum, genu, body and splenium |
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Term
| What is the anterior commisure? |
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Definition
• just caudal to the rostrum of the corpus callosum
• interconnects parts of the two temporal lobes |
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Term
| What is the posterior commisure? |
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Definition
| • found near the base of the pineal gland just dorsal to the cerebral aqueduct |
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Term
| Corticofugal are ____________. |
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Definition
| axons that arise from the cerebral cortex and project to outside targets |
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Term
| Corticopetal are _______________. |
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Definition
| axons that originate outside of the cerebrum and project to the cortex |
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Term
| Corticofugal are also known as __________ while corticopetal are also known as _____________. |
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Definition
| corticospinal, thalamocortical |
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Term
| What is the internal capsule? |
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Definition
| zone containing corticofugal and corticopetal fibers |
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Term
| What the the three parts of the internal capsule? |
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Definition
| anterior limb, posterior limb, genu |
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Term
| What fibers does the anterior limb contain? |
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Definition
| fibers that interconnect the anterior thalamic nuclei with areas of the frontal lobe and cingulated gyrus (i.e. parts of the limbic system |
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Term
| What does the posterior limb contain? |
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Definition
• corticospinal tracts arising from the motor cortex and projecting to the contralateral spinal cord
o somatotopically arrange in the caudal half of the posterior limb
• geniculocalcarine tract (optic radiations) convey visual input from the lateral geniculate nucleus to the occipital cortex |
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Term
| What does the genu contain? |
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Definition
| contains corticonuclear (corticobulbar) fibers that arise in the precentral gyrus and project to the motor nuclei of cranial nerves |
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Term
| What cells line the ventricles? |
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Definition
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Term
| What is the function of the choroid plexus? |
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Definition
| for production of most of the CSF |
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Term
| What are the parts of the ventricular system? |
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Definition
| lateral ventricles->interventricular foramen of Monro->third ventricle->cerebral aqueduct->fourth ventricle->foramen of Magendie (1) and foramina of Luschka (2)->central canal |
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Term
| What is called when the ventricles become enlarged because of CSF? |
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Definition
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Term
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Definition
| increase in CSF volume and an increase in CSF pressure |
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Term
| non-communicating or obstructive hydrocephalus? |
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Definition
| obstruction of the flow of CSF within the ventricular system particularly at sites of narrowing-foramina of Monro, cerebral aqueduct or foramina of Magendie and Luschka |
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Term
| communicating hydrocephalus? |
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Definition
| • blockage of CSF may occur by impeding resorption of CSF into the venous system |
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Term
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Definition
| • the brains of older individuals frequently show what seem to be enlarged ventricles but is in reality a compensatory enlargement of ventricles due to atrophy of brain such as with aging or in Alzheimer’s disease |
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