Hello,
In reference to the same presentation on neuroanatomy and neuroscience.
The Blood supply to the posterior limb of the nternal capsule is said to be the posterior cerebral artery.
The posterior limb of the internal capsule is supplied by the lenticulostriate branches of the MCA. Sometimes the ACA, but not often.
References:
http://www.umassmed.edu/strokestop/module_three/module_fr.html
http://stanfordmedicine25.stanford.edu/the25/ics.html
Andrew Wagner, PT, DPT