Which muscle has an attachment to the mastoid process as part of its insertion?

Which muscle has an attachment to the mastoid process as part of its insertion?

• A. Longissimus
• B. Iliocostalis
• C. Spinalis
• D. Semispinalis

Answer: (A)

The mastoid process is a key attachment point for muscles that move and stabilize the head, especially those that extend the head. The longissimus muscle, specifically its capitis portion, travels from the upper spine to the mastoid process, so it inserts there. This lets the muscle help extend the head and rotate it toward the same side. The other muscles listed do not insert on the mastoid: iliocostalis attaches to ribs and the transverse processes of vertebrae; spinalis mainly attaches to spinous processes in the upper spine; semispinalis capitis attaches higher up on the occipital bone rather than the mastoid.

The mastoid process is a key attachment point for muscles that move and stabilize the head, especially those that extend the head. The longissimus muscle, specifically its capitis portion, travels from the upper spine to the mastoid process, so it inserts there. This lets the muscle help extend the head and rotate it toward the same side. The other muscles listed do not insert on the mastoid: iliocostalis attaches to ribs and the transverse processes of vertebrae; spinalis mainly attaches to spinous processes in the upper spine; semispinalis capitis attaches higher up on the occipital bone rather than the mastoid.