The correct spelling of "musculus pterygoideus internus" can be quite tricky. The first word, "musculus," is spelled as it sounds. However, "pterygoideus" has several silent letters and is pronounced /tɛˈrɪɡɔɪdiəs/. Finally, "internus" is spelled as it sounds with no silent letters and is pronounced /ɪnˈtɜrnəs/. This muscle is responsible for the movement of the jaw and is located deep in the skull. Though difficult to spell, it is an important term in anatomy and physiology.
The term "musculus pterygoideus internus" refers to a specific muscle located within the human anatomy. It is commonly known as the internal pterygoid muscle and is one of the several muscles that make up the muscles of mastication or chewing.
The internal pterygoid muscle is situated within the head and neck region. It is found deep within the pterygopalatine fossa, a space located below the base of the skull and behind the maxilla bone. The muscle originates from the medial surface of the lateral pterygoid plate, a bony structure within the skull, and inserts into the condylar process of the mandible, the part responsible for articulating with the skull to form the temporomandibular joint.
Functionally, the musculus pterygoideus internus plays a crucial role in the process of mastication or chewing. It works in conjunction with the other muscles of mastication to bring about the motions required for effective chewing and grinding of food. Contraction of this muscle helps to elevate and protrude the mandible, allowing for the necessary movements required during chewing and speaking.
Overall, the musculus pterygoideus internus is an important component of the masticatory apparatus and contributes significantly to the process of chewing, allowing for effective food mastication and oral function.
Origin, pterygoid fossa of sphenoid and tuberosity of maxilla; insertion, inner surface of lower jaw between angle and mylohyoid groove; action, raises mandible, closing jaw; nerve supply, internal pterygoid from third division of trigeminus.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.