muscles of mastication?

Question

im studying for my dental nursing exam and im really stuck on the muscles of mastication. I know they are there to help your jaw move so u can eat(i think can u tell me if thats right) but i need to know which one does what job?
please let me know im going mental!!!

Answer 1

Good for you, god i remember studying for my exams so i know how you feel.
Right here goes, see how much i actually do remember.
There are 4 muscles of mastication which are all supplied by the Mandibular division of the trigeminal nerve.
Masseter- The masseter muscle elevates the mandible to close the jaws, originates from the boredr of the Zygomatic Arch and inserts on the outer surface of the Ramus and angle of the mandible.

Temporalis-Anterior fibres of the temporalis elevate the mandible and posterior fibres retract it, so this muscle closes and pulls the mandible backwards.
Originates from the Temporal fossa on the lateral surface of temporal bone.

Lateral Pterygoid-Pulls the mandible forwards and down, opening the jaws, originates by 2 heads from the infra temporal surface of the greater wing of the Sphenoid and lateral surface of the lateral pterygoid.

Medial Pterygoid-elevates the mandible pulling it forward assisting in the closing of the jaws, originates by 2 heads that wrap around the lateral pterygoid muscle attaching it from the medial surface of the lateral pterygoid plate, the palatine bone and the tuberosity of the maxilla!

And that my little aspirating beauty is about it, try pinning pictures up in your surgery and look at them every day.

If you need any help drop me a line and if i can help you with anything i will try my best!

Answer 2

Mastication is accomplished through the activity of the four muscles of mastication.

The masseter
The temporalis
The medial pterygoid
The lateral pterygoid
Unlike most of the other facial muscles, which are innervated by the facial nerve, or CN VII, the muscles of mastication are all innervated by the trigeminal nerve, or CN V. More specifically, they are innervated by the mandibular branch, or V3. This is a testament to their shared embryological origin from the first branchial arch. The muscles of facial expression, on the other hand, derive from the second branchial arch.

In humans, the mandible, or lower jaw, is connected to the temporal bone of the skull via the temporomandibular joint, an extremely complex joint which permits movement in all planes. The muscles of mastication originate on the skull and insert into the mandible, thereby allowing for jaw movements during contraction. The mandible is the only bone that moves during mastication and other activites, such as talking.

Each of these primary muscles of mastication is paired, with each side of the mandible possessing one of the four. While these four muscles are the primary participants in mastication, other muscles are usually if not always helping the process, such as those of the tongue and the cheeks.

Answer 3

LaLa's list is great. Some people include the Platysma (neck muscle) in the naming of the muscles of mastication, because it help to open the jaw. Not everyone does, though. I'd hate to do without mine!

Answer 4

I always remembered it as "TIME" (time to eat - haha)

Temporal
Internal (medial) pterygoid
Masseter
External (lateral) pterygoid

The temporal and masseter both raise the mandible and close the jaws.

The internal (medial) closes the jaw acting with the lateral on same side, pulls mandible to one side, and medial and lateral pterygoids on both sides act together to bring lower jaw forward.

The external (lateral) depresses the mandible to open the jaw.

REMEMBER - the first 3 all close the jaw and the last one is the only one that opens it.

Answer 5

Do an esearch on 'comparative anatomy face muscles' Google brought up a couple of dozen promising titles even after humans and primates are factored out.

Answer 6

Go to a dentist ,