human_reference_atlas Homo sapiens sesamoid bone patella https://upload.wikimedia.org/wikipedia/commons/9/9a/Knee_diagram.svg FMA:24485 patella MESH:D010329 AS galen:Patella Wikipedia:Patella UBERON:0002446 patella MA:0001374 knee cap patella patellar UMLS:C0030647 The patella, also known as the knee cap or kneepan, is the largest sesamoid bone in the human body. The primary functional role of the patella is knee extension. The patella has convergently evolved in placental mammals and birds; marsupials have only rudimentary, non-ossified patellae. In more primitive tetrapods, including living amphibians and reptiles, the muscle tendons from the upper leg are attached directly to the tibia, and the patella is not present. See also: fabella. knee bone EMAPA:35668 NCIT:C33282 uberon SCTID:182083008 GAID:203 A large sesamoid bone found in the distal femur/proximal tibial region of the hindlimb of tetrapods. The patella is the attachment site for proximal hindlimb tendons.[PHENOSCAPE:ad]. free part of leg bone