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trigeminal nucleus

either of two nuclei associated with the three main roots of each trigeminal nerve. The spinal trigeminal nucleus extends downward in the medulla oblongata to the upper region of the spinal cord and receives fibers from pain and temperature receptors. The principal sensory trigeminal nucleus receives large myelinated fibers from pressure receptors in the skin and relays impulses to the thalamus.

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Psychology term of the day

January 26th 2025

congenital oculomotor apraxia

congenital oculomotor apraxia

a condition, present at birth, in which a child is unable to fixate objects normally (see oculomotor apraxia). It is characterized by the absence of saccades and smooth-pursuit eye movements in the horizontal plane, but vertical eye movements are preserved: Children with this condition are often mistakenly thought to be blind. Between the ages of 4 and 6 months, they develop thrusting, horizontal head movements, sometimes blinking prominently or rubbing their eyelids when they attempt to change fixation. The cause of congenital oculomotor apraxia is unknown, but there is usually an improvement with age.