What is atlas and axis?
The atlas and axis vertebrae are the two most superior bones in the vertebral column, and they are part of the seven cervical vertebrae. The atlas is the top-most bone, sitting just below the skull; it is followed by the axis. Together, they support the skull, facilitate neck movement, and protect the spinal cord.
How are the atlas and axis different?
The atlas is the topmost vertebra and, with the axis (the vertebra below it), forms the joint connecting the skull and spine. The atlas and axis are specialized to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head.
How are the atlas and axis unique?
Note uniquely shaped atlas and axis (C1 and C2). The atlas is ring-shaped and does not have a body, unlike the rest of the vertebrae. Fused remnants of the atlas body have become part of C2, where they are called the odontoid process, or dens.
Why are atlas and axis different from other vertebrae?
The main difference between atlas and axis vertebrae is that atlas is the first cervical vertebra, which supports the skull whereas axis is the second cervical vertebra, which forms the pivot upon the atlas. Furthermore, atlas help to hold the head upright while axis allows the head to turn side to side.
How do you remember atlas and axis?
You can use a meal-related mnemonic to remember them – imagine a crunchy breakfast at 7 am (7 cervical vertebrae), a tasty lunch at 12 noon (12 thoracic vertebrae), and a light dinner at 5 pm (5 lumbar vertebrae).
What are the differences in location and function of the atlas and axis?
Does the atlas or axis rotate?
The ring-shaped atlas rotates around the dens, which is the peg-like bony projection of the axis. Articular cartilage enables the smooth movements around the dens and within the facets, while muscles, tendons, and ligaments help hold the vertebrae together.
What type of bone is the atlas?
cervical vertebrae
The atlas bone is the first of seven cervical vertebrae (vertebra cervicalis I or C1). It supports the weight of the skull. The name for the bone was derived from a deity of Greek mythology called Atlas, who supported the heavens.
Why is C2 called axis?
Axis: The axis is the second cervical vertebra (symbol: C2). It is called the “axis” because the uppermost cervical vertebra (called the atlas) rotates about the odontoid process of C2. The joint between the axis and atlas is a pivot type of joint. It allows the head turn.
What is the main axis of our body?
The axial skeleton forms the central axis of the body and includes the bones of the skull, ossicles of the middle ear, hyoid bone of the throat, vertebral column, and the thoracic cage (ribcage) (Figure 1).
What part of the axis articulates with the atlas?
It is comprised of two bony arches with two bony masses laterally. It articulates with the Occiput above and C2 (the Axis) below.