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The occipital bone is located at the back of the skull and is the origin point for several muscles, including the occipitalis muscle, which lies on the occipital bone and is part of the epicranial muscle group. The occipitalis muscle, also known as the occipital belly of the occipitofrontalis muscle, is responsible for facial expressions and scalp retraction. It works in conjunction with the frontalis muscle to move the scalp backward and forward. In addition to the occipitalis muscle, there are four suboccipital muscles located deep within the neck, beneath the occipital bone. These muscles play a crucial role in maintaining head posture and facilitating movements such as extension, lateral flexion, and rotation. The suboccipital muscles are also associated with cervicogenic and tension headaches due to their proximity to the vertebral artery and connections with the dura mater.
| Characteristics | Values |
|---|---|
| Name of the muscle | Occipitalis muscle |
| Synonyms | Occipital belly of the occipitofrontalis muscle, occipital belly of epicranius muscle |
| Part of | Epicranial muscle group |
| Origin | Lateral two-thirds of the superior nuchal line of the occipital bone and adjacent region of the mastoid part of the temporal bone |
| Insertion | Epicranial aponeurosis |
| Function | Retracts the scalp, moves the scalp backwards and forwards, draws eyebrows up, wrinkles forehead |
| Innervation | Posterior auricular branch of the facial nerve (CN VII) |
| Blood supply | Frontal branch of the superficial temporal artery, the supra-orbital artery, and the supratrochlear artery |
| Related muscles | Frontalis muscle, epicranial aponeurosis |
| Related conditions | Tension headaches |
| Related muscle groups | Suboccipital muscles |
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What You'll Learn
- The suboccipital muscles are a group of four muscles located underneath the occipital bone
- The suboccipital triangle is an area bordered by three of the suboccipital muscles
- The occipitalis muscle is a muscle of facial expression and forms part of the epicranial muscle group
- The obliquus capitis inferior is the most inferiorly positioned of the suboccipital muscles
- The suboccipital muscles are important because of their close relationship to the vertebral artery
The suboccipital muscles are a group of four muscles located underneath the occipital bone
The four suboccipital muscles are named according to their position below the occipital bone and are as follows: rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior. The rectus capitis posterior major is the larger of the rectus capitis muscles and originates from the spinous process of the C2 vertebrae, inserting into the lateral part of the inferior nuchal line of the occipital bone. The rectus capitis posterior minor, on the other hand, originates from the posterior tubercle of the posterior arch of the C1 vertebra and inserts into the medial part of the inferior nuchal line of the occipital bone.
The obliquus capitis inferior is unique among the group as it is the only muscle that does not attach to the cranium. It originates from the spinous process of the C2 vertebra and inserts into the transverse process of the atlas (C1 vertebra). The obliquus capitis superior, in contrast, is smaller and originates from the transverse process of the atlas, inserting into the occipital bone between the superior and inferior nuchal lines.
These four muscles collectively contribute to the formation of the boundaries of the suboccipital triangle, a significant anatomical landmark. This triangle houses essential structures such as the suboccipital nerve, the vertebral artery, and the suboccipital venous plexus. The suboccipital triangle is clinically important, especially during surgical procedures in the posterior cervical region, as it helps localise the vertebral artery and suboccipital nerve, preventing life-threatening bleeding.
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The suboccipital triangle is an area bordered by three of the suboccipital muscles
The suboccipital muscles are a group of four muscles located underneath the occipital bone in the posterior region of the neck. These muscles are the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior. The suboccipital triangle is an area bordered by three of these suboccipital muscles. The suboccipital nerve (C1), vertebral artery (V3), and suboccipital venous plexus are all contained within the suboccipital triangle.
The suboccipital muscles are deep to the semispinalis capitis muscle, and they collectively act to extend and rotate the head. The semispinalis capitis muscle forms the roof of the suboccipital triangle. The suboccipital triangle is an important anatomical landmark, especially for surgeons operating in the posterior cervical region, as it allows for the localisation of the vertebral artery and suboccipital nerve.
The suboccipital nerve is the posterior ramus of the C1 spinal nerve, and it innervates the four suboccipital muscles. The vertebral artery enters the skull through the foramen magnum after passing through the suboccipital triangle and piercing the posterior atlantooccipital membrane. The suboccipital venous plexus receives deoxygenated blood from the back of the scalp, which then drains into the deep cervical vein, vertebral vein, and brachiocephalic vein.
The suboccipital triangle has three boundaries: a superomedial boundary formed by the inferolateral aspect of the rectus capitis posterior major muscle, a superolateral boundary formed by the inferomedial aspect of the obliquus capitis superior muscle, and an inferolateral boundary formed by the superior aspect of the obliquus capitis inferior muscle. These muscles originate from the processes of the atlas or axis and insert near the inferior nuchal line of the occipital bone, except for the obliquus capitis inferior, which inserts onto C1.
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The occipitalis muscle is a muscle of facial expression and forms part of the epicranial muscle group
The occipitalis muscle is a muscle of facial expression and is part of the epicranial muscle group. It is also referred to as the occipital belly of the occipitofrontalis muscle. The occipitalis muscle, along with the frontalis muscle, forms the occipitofrontalis muscle. Together, these two muscles draw the eyebrows up and wrinkle the forehead. They can also move the scalp backward and forward.
The occipitalis muscle originates from the lateral two-thirds of the superior nuchal line of the occipital bone and the adjacent region of the mastoid part of the temporal bone. It ascends to join onto the epicranial aponeurosis, a broad tendon that runs from the superior portion of the frontal bone and covers the parietal bones to the lambdoid suture. The occipitalis muscle is innervated by the posterior auricular branch of the facial nerve (CN VII).
The occipitalis muscle is one of the muscles of facial expression. It functions to retract the scalp, allowing for movement of the scalp backward and forward. Acting in coordination with the frontalis muscle, the occipitalis muscle can move the entire scalp in a backward and forward motion.
The suboccipital muscles are a group of four muscles situated underneath the occipital bone. These muscles are located within the suboccipital compartment of the neck, deep to the sternocleidomastoid, trapezius, splenius, and semispinalis muscles. The suboccipital muscles collectively act to extend and rotate the head, providing postural support to the head and neck.
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The obliquus capitis inferior is the most inferiorly positioned of the suboccipital muscles
The suboccipital muscles are a group of four muscles situated underneath the occipital bone. They are located within the suboccipital compartment of the neck, deep to the sternocleidomastoid, trapezius, splenius, and semispinalis muscles. The four muscles are the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior.
The obliquus capitis inferior is one of the three muscles that form the boundaries of the suboccipital triangle. This triangle is an important anatomical landmark that allows for the localisation of the vertebral artery and the suboccipital nerve. The suboccipital nerve and vertebral artery supply all four suboccipital muscles and lie in the central part of the triangle.
The suboccipital muscles function as postural muscles, providing support for the head and neck. They also allow for head movement, including extension, lateral flexion, and rotation. These muscles are clinically important due to their close relationship with the vertebral artery and their involvement in certain types of headaches, such as cervicogenic and tension headaches.
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The suboccipital muscles are important because of their close relationship to the vertebral artery
The suboccipital muscles are a group of four muscles located in the posterior region of the neck, underneath the occipital bone. These muscles are the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior. The suboccipital muscles function as postural muscles, providing support to the head and neck, and allowing for head movement. They are innervated by the suboccipital nerve, which is the dorsal ramus of the C1 spinal nerve.
The close relationship between the suboccipital muscles and the vertebral artery also has clinical implications. Contraction of the suboccipital muscles can lead to minor artery compression and reduced blood flow, resulting in symptoms such as light-headedness and dizziness. Additionally, strain on these muscles due to constant movement or injury can cause cervicogenic headaches, which are often mistaken for migraines or tension headaches.
Furthermore, the suboccipital muscles have been implicated in the pathogenesis of cervicogenic headaches due to their connections with the dura mater. Understanding the relationship between the suboccipital muscles and the vertebral artery is essential for developing effective treatments and interventions for patients experiencing cervicogenic headaches or other related conditions.
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Frequently asked questions
The occiput is the back of the head, or the occipital region.
The occipitalis muscle lies on the occipital bone. It is also referred to as the occipital belly of the occipitofrontalis muscle and is a muscle of facial expression.
The suboccipital region is home to four small paired muscles: the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior.
