päälihaksista

Päälihakset, also known as cranial muscles or muscles of the head, are a complex group of muscles that control a wide range of facial expressions, chewing, and other movements of the head and neck. These muscles can be broadly categorized into two main groups: muscles of facial expression and muscles of mastication.

The muscles of facial expression are primarily located on the face and are responsible for creating expressions like smiling, frowning, and surprise. They originate from the bones of the skull and insert into the skin, allowing for the subtle and varied movements that convey emotion. Examples include the orbicularis oculi, which closes the eyelid, and the zygomaticus major, which lifts the corners of the mouth for smiling.

The muscles of mastication, also known as the muscles of chewing, are responsible for the movements of the jaw. These muscles work together to open, close, and move the mandible side-to-side, enabling us to bite, chew, and grind food. The primary muscles of mastication include the temporalis, masseter, medial pterygoid, and lateral pterygoid. These muscles are innervated by the trigeminal nerve, a major cranial nerve.

In addition to these functional groups, there are also muscles in the neck that support the head and allow for its movement, such as the sternocleidomastoid and trapezius. The coordinated action of all these muscles allows for the intricate and essential functions of the head.