In anatomy, the atlas (C1) is the most superior (first) cervical vertebra of the spine and is located in the neck.
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The suboccipital nerve is the dorsal primary ramus of the first cervical nerve (C1). It exits the spinal cord between the skull and the first cervical vertebra, the atlas.
The greater occipital nerve is a nerve of the head. It is a spinal nerve, specifically the medial branch of the dorsal primary ramus of cervical spinal nerve 2. It arises from between the first and second cervical vertebrae, ascends, and then passes through the semispinalis muscle. It ascends further to supply the skin along the posterior part of the scalp to the vertex. It supplies sensation to the scalp at the top of the head, over the ear and over the parotid glands.
In tetrapods, cervical vertebrae are the vertebrae of the neck, immediately below the skull. Truncal vertebrae lie caudal of cervical vertebrae. In sauropsid species, the cervical vertebrae bear cervical ribs. In lizards and saurischian dinosaurs, the cervical ribs are large; in birds, they are small and completely fused to the vertebrae. The vertebral transverse processes of mammals are homologous to the cervical ribs of other amniotes. Most mammals have seven cervical vertebrae, with the only three known exceptions being the manatee with six, the two-toed sloth with five or six, and the three-toed sloth with nine.
The obliquus capitis inferior muscle is a muscle in the upper back of the neck. It is one of the suboccipital muscles. Its inferior attachment is at the spinous process of the axis; its superior attachment is at the transverse process of the atlas. It is innervated by the suboccipital nerve. The muscle rotates the head to its side.
The obliquus capitis superior muscle is a small muscle in the upper back part of the neck. It is one of the suboccipital muscles. It attaches inferiorly at the transverse process of the atlas ; it attaches superiorly at the external surface of the occipital bone. The muscle is innervated by the suboccipital nerve.
The vertebral arteries are major arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, midline basilar artery. As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.
The splenius capitis is a broad, straplike muscle in the back of the neck. It pulls on the base of the skull from the vertebrae in the neck and upper thorax. It is involved in movements such as shaking the head.
The rectus capitis posterior minor is a muscle in the upper back part of the neck. It is one of the suboccipital muscles. Its inferior attachment is at the posterior arch of atlas; its superior attachment is onto the occipital bone at and below the inferior nuchal line. The muscle is innervated by the suboccipital nerve. The muscle acts as a weak extensor of the head.
The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck.
The nuchal lines are four curved lines on the external surface of the occipital bone:
The squamous part of occipital bone is situated above and behind the foramen magnum, and is curved from above downward and from side to side.
The suboccipital triangle is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:
The posterior atlantooccipital membrane is a broad but thin membrane extending between the posterior margin of the foramen magnum above, and posterior arch of atlas below. It forms the floor of the suboccipital triangle.
The posterior branches of cervical nerves branch from the dorsal rami of the cervical nerves.
The following outline is provided as an overview of and topical guide to human anatomy:
The suboccipital muscles are a group of muscles defined by their location to the occiput. Suboccipital muscles are located below the occipital bone. These are four paired muscles on the underside of the occipital bone; the two straight muscles (rectus) and the two oblique muscles (obliquus).
Each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.
The myodural bridge or miodural ligament is a bridge of connective tissue that extends between the suboccipital muscles and the cervical spinal dura mater, the outer membrane that envelops the spinal cord. It provides a physical connection between the musculoskeletal and nervous systems, and the circulation of cerebrospinal fluid. Its importance has been highlighted by various authors.
