What is atlas and axis vertebrae?
What is atlas and axis vertebrae?
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.
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.
What is the role of the atlas and axis?
The atlas and axis support the head on the lower cervical spine while providing for considerable mobility in flexion, extension, rotation and lateral bending. The first two vertebrae also function as conduits for the cervical cord and vertebral arteries.
What is the axis vertebra?
Introduction. The Axis (C2 vertebra) also known as epistropheus forms the pivot upon which the first cervical vertebra (the Atlas), which carries the head, rotates. The axis is composed of a vertebral body, heavy pedicles, laminae, and transverse processes, which serve as attachment points for muscles.
What is the meaning of Atlas vertebra?
(ăt′ləs) pl. at·lases. Anatomy The top or first cervical vertebra of the neck, which supports the skull.
What are the differences between atlas and axis?
The key difference between atlas and axis vertebrae is that the atlas vertebra is the topmost vertebra which holds the skull while axis vertebra is the second topmost vertebra which provides an axis to rotate the skull and atlas vertebra when the head moves side to side.
What makes the axis and atlas unique?
The atlas’s chief peculiarity is that it has no body. It is ring-like and consists of an anterior and a posterior arch and two lateral masses. The atlas and axis are important neurologically because the brainstem extends down to the axis.
What is the function of atlas vertebra?
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.
Which vertebra is called the vertebra Prominens?
Vertebra prominens is the name of the seventh cervical vertebra. The most distinctive characteristic of this vertebra is the existence of a long and prominent spinous process which is palpable from the skin surface, hence the name.
Which vertebra is also known as the atlas?
The atlas (plural: atlases) is the first cervical vertebra, commonly called C1. It is an atypical cervical vertebra with unique features. It articulates with the dens of the axis and the occiput, respectively allowing rotation of the head, and flexion, extension and lateral flexion of the head.
How do the axis and atlas articulate?
The facets articulate with rounded condyles on the underside of the skull’s occipital bone. This junction allows the head to nod up and down. Directly below the atlas bone is the axis bone (C2). Pivot and gliding joints linking the two bones allow the head to move side-to-side.
What is the function of the atlas vertebra?