What are the 8 muscles of mastication?
Muscles of mastication
- The primary muscles include: Masseter. Temporalis. Lateral pterygoid. Medial pterygoid.
- The secondary or accessory muscles are: Buccinator. Suprahyoid muscles (digastric muscle, mylohyoid muscle, and geniohyoid muscle) Infrahyoid muscles (the sternohyoid, sternothyroid, thyrohyoid, and omohyoid muscle)
What are the 5 muscles of mastication?
The muscles of mastication are a group of muscles that consist of the temporalis, masseter, medial pterygoid and lateral pterygoid muscles. The temporalis muscle is situated in the temporal fossa, the masseter muscle in the cheek area, while the medial and lateral pterygoids lie in the infratemporal fossa.
What are the 4 mastication muscles?
- Temporalis Muscle. The temporalis muscle is a fan-shaped muscle with anterior fibers that have a vertical orientation, mid fibers have an oblique orientation, and posterior fibers have a more of a horizontal orientation.
- Medial Pterygoid.
- Lateral Pterygoid.
- Accessory Muscles of Mastication.
How many muscles used smiling?
Most of the 43 muscles we use to smile are under the control of the seventh cranial nerve. This is also referred to as the facial nerve. It begins at the cerebral cortex, emerging from the skull in front of the ears. From there it separates into five branches known as the primary branches which we discussed earlier.
How many muscles are in the jaw?
There are three jaw-closing muscles (masseter, temporalis, and medial pterygoid) and two jaw-opening muscles (lateral pterygoid and digastric).
Is your tongue a muscle?
The tongue is an extremely movable set of muscles, which is well-supplied with blood and has many nerves. The tongue muscles have an oblong shape and are covered with a dense layer of connective tissue. Above this layer, a special kind of mucous membrane makes up the surface of the tongue.
Why is buccinator not a muscle of mastication?
It is not a primary muscle of mastication – it does not move the jaw – and this is reflected in its motor innervation from the facial nerve. However, proprioceptive fibres are derived from the buccal branch of the mandibular part of the trigeminal nerve (CN V).
Are there muscles in your lips?
Anatomy. Lip function is mainly controlled by the orbicularis oris muscle, which completely encircles the opening of the mouth, thus providing oral competence. This muscle is not perfectly circular, because the upper and lower lip muscle components decussate at the commissures.