3. Introduction
The cervical spine is the most superior portion of the vertebral column, lying
between the cranium and the thoracic vertebrae.
It consists of seven distinct vertebrae,three of which are given unique
characteristics (atypical)
The first cervical vertebrae (C1) atlas.
The second cervical vertebrae (C2) axis.
The seventh cervical vertebrae (C7).
Others are typical (C3, C4, C5, C6).
5. Characteristic Features
The cervical vertebrae have three features which distinguish them from
thoracic vertebrae:
Triangular vertebral foramen.
Bifid spinous process – this is where the spinous process splits into two
distally.
Transverse foramina – holes in the transverse processes. They give passage to
the vertebral artery, vein and sympathetic nerves.
6. Atlas
The atlas (C1) differs from the other cervical vertebrae in that it has no
vertebral body and no spinous process.
It also has an articular facet anteriorly, which articulates with the dens of the
axis.
The atlas also has lateral masses on either side of the vertebral arch, which
provide an attachment for the transverse ligament of the atlas.
The posterior arch has a groove for the vertebral artery and C1 spinal nerve.
8. Axis
The axis (C2) is easily identifiable due to its dens (odontoid process) which
extends superiorly from the anterior portion of the vertebra. The dens
articulates with the articular facet of the atlas, in doing so creating the medial
atlanto-axial joint, This allows for rotation of the head independently of the
torso.
10. Joints
The joints of the cervical spine can be divided into two groups – those that are present throughout
the vertebral column, and those unique to the cervical spine.
There are two different joints present throughout the vertebral column:
Between vertebral bodies – adjacent vertebral bodies are joined by intervertebral discs, made of
fibrocartilage. This is a type of cartilaginous joint, known as a symphysis.
Between vertebral arches – formed by the articulation of superior and inferior articular processes
from adjacent vertebrae, It is a synovial type joint.
11. Joints
Unique to Cervical Spine
The atlanto-axial and atlanto-occipital joints are unique to the cervical spine.
The atlanto-axial joints are formed by the articulation between the atlas and the axis:
There are two lateral atlanto-axial joints which are formed by the articulation between the inferior facets of the lateral
masses of C1 and the superior facets of C2. These are plane type synovial joints.
The medial atlanto-axial joint is formed by the articulation of the dens of C2 with the articular facet of C1. This is a
pivot type synovial joint.
The atlanto-occipital joints consist of an articulation between the spine and the cranium,They occur between then
superior facets of the lateral masses of the atlas and the occipital condyles at the base of the cranium. These are
condyloid type synovial joints, and permit flexion at the head i.e. nodding
13. Ligaments
There are six major ligaments to consider in the cervical spine. The majority of these ligaments are present throughout the entire vertebral
column.
Present throughout Vertebral Column
Anterior and posterior longitudinal ligaments: Long ligaments that run the length of the vertebral column, covering the vertebral bodies and
intervertebral discs.
Ligamentum flavum: Connects the laminae of adjacent vertebrae.
Interspinous ligament: Connects the spinous processes of adjacent vertebrae.
Unique to Cervical Spine
Nuchal ligament: A continuation of the supraspinous ligament. It attaches to the tips of the spinous processes from C1-C7, and also provides
the proximal attachment for the rhomboids and trapezius.
Transverse ligament of the atlas: Connects the lateral masses of the atlas, and in doing so anchors the dens in place.
(Note: Some texts consider the interspinous ligament to be part of the nuchal ligament).
17. Muscles and fascia of neck
Neck Fascia is divided into superficial and deep
The superficial fascia in the neck contains a thin sheet of muscle (the platysma), which begins in the superficial fascia of the
thorax, runs upward to attach to the mandible and blend with the muscles on the face, is innervated by the cervical branch of
the facial nerve [VII].
the deep cervical fascia is
organized into several distinct layers That include:
an investing layer, which surrounds all structures in the neck;
the prevertebral layer, which surrounds the vertebral column and the deep muscles.
the pretracheal layer, which encloses the viscera of the neck;
the carotid sheaths, surrounds common carotid art, jugular vein, vagus nerve
18.
19. Cervical nerves
Ansa cervicals innervate infrahyoid muscles
Accessory nerve (XI) INNERVATES trapezius and sternocleidomastoid
Cervical plexus has
Muscular branches, phrenic nerve(c3,c4,c5) that innervates diaphragm(sensory, motor)
Cervical plexus innervates prevertebral and lateral vertebral cervical muscles
Superficial branches(cutsneous)
Lesser occipital nerve innervates skin of neck and scalp posterior to auricle
Great occpital nerve supplies skin of parotid , ear , mastoid area
Transverse Cervical nerve supplie lateral and anterior part of neck
Supraclavicular nerve supplies skin above clavicle to rib 2
Brachial plexus supplies upper limb