How Many Bones are there in a Human Neck?

The neck, often known as the cervical spine in medical jargon, comprises seven bones. The first bone of the neck is the atlas, which is the connection between the head and the neck area. The axis is the second neck bone on which the head and atlas spin on top of each other. The atlas and axis work together to form the pivot joint, which aids head movement. The anatomy of the cervical vertebrae from C3 to C6 is similar to that of most other vertebrae. They are standard vertebrae. However, the spinous processes of the C7 vertebra are lengthy and thick.

The hyoid bone forms the floor of the oral cavity and the anterior part of the neck. It is a U-shaped bone.

Examples

1. Atlas and Axis: The first cervical vertebra (atlas) articulates with the axis (C2) and occiput of the head. Atlas is distinguished from the other cervical vertebrae by the absence of a vertebral body and a spinous process. In contrast, the atlas has lateral masses connected by an anterior and posterior arch. Each lateral mass has a superior articular facet (for occipital condyle articulation) and an inferior articular facet.

The odontoid process that extends superiorly from the front section of the vertebrae distinguishes the axis (C2). The medial atlanto-axial joint is formed when the odontoid process articulates with the anterior arch of the atlas. This permits the head to rotate independently of the body. The superior articular facets of the axis also articulate with the inferior articular facets of the atlas to generate the two lateral atlanto-axial joints.

2. C3-C7: The bones in the neck are structurally similar to the rest of the spinal column. The rest of the neck’s mobility is distributed evenly across these spinal levels.

3. Hyoid Bone: It is located near the base of the jaw (about C3) and provides attachment for the anterior neck muscles. The hyoid is made up of a body, two large horns, and two smaller horns. The body is the centre portion and has an anterior convex surface and a posterior concave surface. The greater horn extends from either end of the body in the posterior, superior, and lateral directions. It serves as a point of attachment for several neck muscles. The lesser horn develops from the superior side of the hyoid bone, close to the origin of the bigger horn. It is oriented towards the styloid process of the temporal bone. The stylohyoid ligament connects to the lesser horn's apex.