Rectus anterior capitis muscle
Musculus rectus capitis anterior
Rectus capitis anterior is a short, flat muscle running from the front of the atlas to the skull base; it nods the head.
At a glance
- English
- Rectus anterior capitis muscle
- Latin (TA2)
- Musculus rectus capitis anterior
- System
- Muscle
- Region
- Neck
- Side
- Paired, left and right
About the rectus anterior capitis muscle
Rectus capitis anterior is a small prevertebral muscle at the very top of the neck. It lies directly in front of the atlanto-occipital joint, deep to the upper part of longus capitis, which largely hides it. It belongs with longus capitis and longus colli to the group of deep flexors lying on the front of the cervical spine behind the pharynx.
The muscle is short and flat. It arises from the front of the lateral mass of the atlas and from the root of its transverse process. Its fibres run upwards and slightly inwards and end on the underside of the basilar part of the occipital bone, just in front of the occipital condyle and lateral to the attachment of longus capitis.
Because it spans only the atlanto-occipital joint, its action is limited to that joint. Working on both sides it flexes the head on the atlas, as in a small nod of the chin. Acting alone, it may help tilt the head a little to its own side. Its main role is probably to steady the joint and to give fine control and position sense, balancing the larger extensors at the back of the neck.
It is supplied by branches from the loop between the ventral rami of the first and second cervical nerves, and receives blood from the vertebral and ascending pharyngeal arteries. The first cervical nerve emerges between this muscle and rectus capitis lateralis. The muscle is not often injured on its own, but it may be strained with the other deep flexors when the head is jerked backwards.
Attachments, action and supply
- Origin
- Front of the lateral mass and root of the transverse process of the atlas.
- Insertion
- Inferior surface of the basilar part of the occipital bone, in front of the occipital condyle.
- Action
- Flexes the head at the atlanto-occipital joint and steadies it.
- Nerve supply
- Ventral rami of C1 and C2.
- Blood supply
- Vertebral and ascending pharyngeal arteries.
Anthromica
See the rectus anterior capitis muscle where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
