Search results
Results from the WOW.Com Content Network
The digastric muscle (also digastricus) (named digastric as it has two 'bellies') is a bilaterally paired suprahyoid muscle located under the jaw.Its posterior belly is attached to the mastoid notch of temporal bone, and its anterior belly is attached to the digastric fossa of mandible; the two bellies are united by an intermediate tendon which is held in a loop that attaches to the hyoid bone.
These four muscles have different actions, but in general assist in elevating the hyoid bone and widening the esophagus during swallowing.When the two bellies of the digastric contract, they pull upward on the hyoid bone; but if the hyoid is fixed from below, the digastric assists in extreme opening of the mouth such as yawning or taking a large bite of an apple. [1]
The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid , mylohyoid , and digastric muscles (the lateral pterygoid may play a role).
The submandibular space is a fascial space of the head and neck (sometimes also termed fascial spaces or tissue spaces). It is a potential space, and is paired on either side, located on the superficial surface of the mylohyoid muscle between the anterior and posterior bellies of the digastric muscle. [1]
It is a potential space located between the mylohyoid muscle superiorly, the platysma muscle inferiorly, [1] under the chin in the midline. The space coincides with the anatomic region termed the submental triangle , part of the anterior triangle of the neck .
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants. Originally, it included plant morphology , the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
The trigeminal motor nucleus contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid, and anterior belly of the digastric. [1] It is situated in the upper pons, inferior to the lateral part of the floor of the fourth ventricle. [2]
The jugulodigastric lymph nodes are found in the proximity of where the posterior belly of the digastric muscle crosses the internal jugular vein.Nodes are typically around 15 mm in length in adults, and decrease in size during old age. [1]