The rete mirabile of the maxillary artery in the lion (Panthera leo).

The afferent and efferent arterial branches of the maxillary rete were investigated in 4 lion (Panthera s. Felis leo) heads preserved in the author's department. The heads were injected with acryl plastic via the common carotid arteries to make corrosion casts of the carotid system, and examined from the standpoint of comparative anatomy. The following afferent arterial branches were observed. Medial retial branches from the maxillary artery, anterior retial branches from the anterior deep temporal artery and intraretial branches of the maxillary artery passing in the rete. The rete was constructed from the following arterial resources: Most of the lateral and inferior surfaces of the rete and deep part of the maxillary nerve tunnel from the intraretial branches; the posterior surface and posterior part of the lateral surface from the medial retial branches, and the anterosuperior part of the lateral surface from the anterior retial branches. Eight efferent arterial branches were observed. The external ethmoidal, lacrimal, interretial and anastomotic arteries, the extraocular muscular, meningeal and temporal muscular branches and the communicating branch with the external ethmoidal artery. The anastomotic artery was always well developed and played the role of the main supply route to the brain instead of the obliterated internal carotid artery as observed in the cat. Unlike that of the cat, however, the maxillary artery of the lion always passed lateral to the pterygoideus lateralis muscle, and the lateral part of the rete was not constructed because there were no lateral retial branches such as those observed in the cat.