| Suboccipital triangle | |
|---|---|
Artist depiction of the muscles that border the suboccipital triangle. | |
Muscles that border the suboccipital triangle. | |
| Identifiers | |
The suboccipital triangle is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:
The neck is the part of the body, on many vertebrates, that separates the head from the torso. It contains blood vessels and nerves that supply structures in the head to the body. These in humans include part of the esophagus, the larynx, trachea, and thyroid gland, major blood vessels including the carotid arteries and jugular veins, and the top part of the spinal cord.
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).
Contents
- Rectus capitis posterior major - above and medially
- Obliquus capitis superior - above and laterally
- Obliquus capitis inferior - below and laterally
(Rectus capitus posterior minor is also in this region but does not form part of the triangle)
It is covered by a layer of dense fibro-fatty tissue, situated beneath the semispinalis capitis.
The floor is formed by the posterior atlantooccipital membrane, and the posterior arch of the atlas.
In anatomy, the atlas (C1) is the most superior (first) cervical vertebra of the spine.
In the deep groove on the upper surface of the posterior arch of the atlas are the vertebral artery and the first cervical or 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 provide supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.
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.
In the past, the vertebral artery was accessed here in order to conduct angiography of the circle of Willis. In these times a formal angiography of the circle of Willis is performed via catheter angiography, with access usually being acquired at the common femoral artery. Alternatively, a computed tomographic angiogram or magnetic resonance angiogram is performed.
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. This is traditionally done by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.
The circle of Willis is a circulatory anastomosis that supplies blood to the brain and surrounding structures. It is named after Thomas Willis (1621–1675), an English physician.
