midbrain (redirected from midbrains)

midbrain /mid·brain/ (mid´bran) mesencephalon.

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mid·brain (mdbrn)

n.

See mesencephalon.

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midbrain (mid´brān),

n the portion of the brain located superior to the pons and medulla and containing the motor nuclei of the ocular motor and trochlear nerves. It also contains the major pathways and decussations of fibers from the cerebrum and cerebellum.

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midbrain

the short part of the brainstem just rostral to the pons. It contains the nerve pathways between the cerebral hemispheres and the medulla oblongata, and also contains nuclei of the third and fourth cranial nerves. The centers for visual and auditory reflexes, such as moving the head and eyes, are located in the midbrain. Called also mesencephalon.

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midbrain lesion

causes spastic paresis or paralysis, tremor, nystagmus, opisthotonos and depression or coma.

midbrain syndrome

mental depression, ipsilateral oculomotor nerve deficits, and spastic weakness or paralysis of all four limbs or those on the contralateral side of the body. May be caused by cranial trauma, thiamin deficiency, brain tumors, and degenerative or inflammatory disorders of the mesencephalon.