Atlanto-axial joint Atlanto-axial joint The atlantoaxial joint is a joint in the upper part of the neck between the first and second cervical vertebrae; the atlas and axis. It is a pivot joint. The atlantoaxial joint is of a complicated nature. It consists of no fewer than four distinct joints. There is a pivot articulation between the odontoid process of the axis and the ring formed by the anterior arch and the transverse ligament of the atlas. There are three atlantoaxial joints: one median and two lateral: The ligaments connecting these bones are: The atlantoaxial joint in common terminology is actually a
Cold and heat adaptations in humans to that of Caucasians. This indicates the physiological adaptation of individuals that have left Africa for colder climates. During recent evolution (around 50,000 years ago), cold adaptation has selected for an increased metabolism and insulation (body fat). However, these traits cannot be effectively developed during a lifetime in cold conditions as selection takes place over many generations. Therefore, humans are forced to mainly rely on our behavioral and technological skills to live in and survive the cold . There are three types of cold the body is adapted to: extreme cold, moderate cold, and night cold. Extreme cold is characterized