35. Suprahyoid and Infrahyoid muscles

Origin and insertion of the Omohyoid

*Inferior belly:* Superior margin of the Scapula runs mediocranial behind the clavicle and continues as the *Superior belly* runs to attach on the *lateral part of the body of the Hyoid* laterally from the Sternohyoid muscle

Sternohyoid

*Origin* Dorsal side of the manbrium sternum and the sternoclavicular articulation *Insertion* Inferior margin of the Hyoid

OIFI of the Geniohyoid

*Origin* Spine of the mandible *Insertion* Body of the Hyoid *Function* Mandibular depression, and elevates the Hyoid *Innervation* C1-C2 Muscular branches

OIFI of the Mylohyoid

*Origin:* Mylohyoid line of the mandible *Insertion:* Body of the hyoid and on the myhyoid raphe (from the hyoid to the mental spine) *Function:* Mandibular depression - elevates hyoid during swallowing *Innervation:* Mylohyoid n (Mandibular n)

OIFI of the Stylohyoid

*Origin:* Styloid process *Insertion:* Lesser horn *Function:* Elevates and pulls back the hyoid *Innervation:* Facial n.

OIFI of the Digastric muscles

*Posterior belly* from the mastoid notch of the temporal bone to the lesser horn of the hyoid (Digatric branch of VII) *Anterior belly* from the lesser horn to the to the digastric fossa of the mandible (Mylohyoid V3) *Function*: When hyoid is fixed it allows mandibular depression (Anterior belly) and both allows elevation of the Hyoid bone

How many infrahyoid muscles are there? what are they?

4 Sternohyoid Sternothyroid Thyrohyoid Omohyoid

Common innervation of the infrahyoid

Cerbical plexus (Deep ansa)

Origin and insertion of the Thyrohyoid

Cranial enlargement of the Sternohyoid from the Oblique thyroid line to the lateral part of the hyoid-bone and greater horn

Common function of the infrahyoid muscles?

Fixates the hyoid pulls the hyoid to the sternum

Origin and insertion of the Sternothyroid

Origin: Behind the sternohyoid from the dorsal side of the manubrium of the sternum and the 1st rib gristle Insertion: Oblique line of the thryoid cartilage

How many suprahyoid muscles are there? Name them

There are 4. 1. Mylohyoid 2. Digastric (Anterior and posterior) 3. Stylo-hyoid 4. Geniohyoid