Which part of the internal capsule contains the corticonuclear (corticobulbar) fibres?
- A Anterior limb
- B Genu ✓
- C Posterior limb
- D Retrolentiform part
Correct answer: B. Genu
Explanation
The genu of the internal capsule carries corticonuclear fibres to the cranial nerve motor nuclei. The anterior limb carries frontopontine and thalamocortical fibres, while the posterior limb carries corticospinal fibres plus ascending thalamocortical sensory fibres, which is why a posterior limb stroke causes contralateral hemiplegia with hemianaesthesia. The retrolentiform part contains optic and auditory radiations. This topography explains why small capsular strokes often spare the face or leg selectively.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.