Definition of third ventricle in US English:

third ventricle


  • The central cavity of the brain, lying between the thalamus and hypothalamus of the two cerebral hemispheres.

    • ‘The lateral ventricles were slightly dilated, but there was no dilation or elongation of the third ventricle or displacement of adjacent hypothalamic structures.’
    • ‘Examination of the brain revealed only enlarged lateral and third ventricles.’
    • ‘The lateral and third ventricles were slightly dilated.’
    • ‘In the central nervous system, gangliocytomas are most often found in the floor of the third ventricle or hypothalamus and in the temporal and frontal lobes.’
    • ‘The gross cerebral anatomy is normal and I was able to identify the thalami, septum pelucidum, falx, third ventricle and lateral ventricles which appear normal.’