Corpus: Spinalis muscles: Unterschied zwischen den Versionen

The spinalis muscles are part of the interspinal system within the autochthonous back muscles.

The spinal muscles can be regionally divided into three parts:

• Musculus spinalis thoracis
• Musculus spinalis cervicis
• Musculus spinalis capitis (often absent in most people)

Origin

The spinalis thoracis muscle originates from the spinous processes of the lower thoracic vertebrae (T10, T11, T12) and the 1st and 2nd lumbar vertebrae (L1, L2). The spinalis cervicis muscle originates from the spinous processes of the 4th to 7th cervical vertebrae (C4-C7). The spinalis capitis muscle, if present, originates from the spinous processes of the lower cervical and upper thoracic vertebrae.

Attachment

The spinalis thoracis muscle attaches to the spinous processes of the upper thoracic vertebrae. The spinalis cervicis muscle attaches to the spinous processes of the 2nd and 3rd cervical vertebrae (C2, C3). The spinalis capitis muscle attaches between the superior and inferior nuchal lines of the occipital bone, along with the semispinalis capitis muscle.

The spinal muscles are innervated by the medial branches of the posterior rami of the respective segmental spinal nerves.

The spinal muscles in the cervical and thoracic regions extend the spinal column. The spinalis capitis muscle, when present, functions in unilateral rotation of the head to the opposite side and bilateral dorsiflexion in the atlantooccipital joint and the cervical spine.