The sesamoid bone of musculus abductor pollicis longus (os radiale externum or prepollex) in primates.
The sesamoid bone of the musculus abductor pollicis longus has been investigated in a series of 276 nonhuman primates representative of 37 genera, and in a series of 300 radiographs of human subjects. The presence of this ossicle in primates is a primitive characteristic. It is present in all nonhuman primates, and is generally articulated with both the scaphoid and trapezium. Modifications of the general mammalian pattern exist only in Gorilla gorilla, where the sesamoid bone is observed in about half of the individuals, and in Homo, where this ossicle is normally absent.
Le Minor
J M
JM
Institute of Normal Anatomy, Faculty of Medicine, Strasbourg, France.
D000818:Animals; D005075:Biological Evolution; D002348:Carpal Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D002358:Cartilage, Articular / Q000033:anatomy & histology; D006801:Humans; D018482:Muscle, Skeletal; D011323:Primates / Q000033:anatomy & histology*; D011859:Radiography; D012716:Sesamoid Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013933:Thumb