Pronunciation: [rjˈuːəl bˈə͡ʊn] (IPA) 
"Ruell bone" is a term that refers to the bone that supports the lower jaw of a mammal. Its correct spelling is "mandibular ramus". The reason for this discrepancy is rooted in the evolution of language and the evolution of science. "Ruell bone" is a historical term, while "mandibular ramus" is the anatomically correct term. The phonetic transcription for "mandibular ramus" is /mænˈdɪbjələr ˈreɪməs/.
Ruell bone, also referred to as the Ruel bone or the astragalus bone, is a small bone located in the ankle joint of mammals. Specifically, it is found between the tibia, fibula, and talus bones, and is considered an important component of the tarsus, or the hindfoot region.
The ruell bone serves multiple functions within the structure and movement of the ankle joint. It acts as a crucial link between the leg and the foot, transferring weight and enabling locomotion. This bone plays a key role in maintaining balance and providing stability during weight-bearing activities, such as walking, running, and jumping.
Anatomically, the ruell bone has a convex upper surface that forms a part of the ankle joint, while the lower surface is irregular and articulates with other bones of the foot. It also features distinct articular surfaces for connections with the tibia and talus bones.
The ruell bone is present and plays a significant role in a wide range of mammals, including humans, primates, carnivores, ungulates, and many others. Despite some variations in shape and size among different species, its overall function and importance remain consistent.
In conclusion, the ruell bone is a small bone located in the ankle joint that contributes to the stability and mobility of the foot during weight-bearing activities.
