====== P1 segment ======

peduncular segment(P1)

● mesencephalic perforating aa. (⇒ tectum, cerebral peduncles, and these nuclei: Edinger- Westphal, oculomotor and trochlear)

● interpeduncular thalamoperforators (1st of 2 groups of posterior thalamoperforating aa.)

● medial post. choroidal (most from P1 or P2)

● “[[artery of Percheron]]”: a rare anatomic variant
((Percheron G. The anatomy of the arterial supply of the human thalamus and its use for the interpreta- tion of the thalamic vascular pathology. Z Neurol. 1973; 205:1–13))
in which a solitary arterial trunk arising
from the proximal segment of one PCA supplies the paramedian thalami and rostral midbrain bilaterally

[[P1]] of the [[posterior cerebral artery]]: from it origin at the termination of the [[basilar artery]] to [[posterior communicating artery]] (PCOM), within [[interpeduncular cistern]].
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(AKA mesencephalic, precommunicating, circular, peduncular, basilar…). The long and short circumflex and [[thalamoperforating arteries]] arise from P1