Hyoid bone Flashcards
What are the infrahyoid muscles?
- Omohyoid
- Superior belly
- Inferior belly - Sternohyoid
- Sternothyroid
- Thyrohyoid
What is the arterial supply for the infrahyoid muscles?
Superior and inferior thyroid artery
What is the innervation of the omohyoid muscle?
Anterior rami of C1-3
- Carried by a branch of the ansa cervicalis
What is the action of the omohyoid muscle?
Depresses the hyoid bone
What is the attachment of the superior belly of the omohyoid bone?
- Attached to inferior belly by intermediate tendon (which is anchored to the clavicle by the deep cervical fascia)
- Then ascends to attach to the hyoid bone
What is the attachment of the inferior belly of the hyoid bone?
- Superior border of scapula
- Runs superomedially underneath the sternocleidomastoid muscle
- Attaches to intermediate tendon
What attaches the superior and inferior bellies of the omohyoid bone?
Intermediate tendon
- Anchored to clavicle by deep cervical fascia
What is the innervation of the sternohyoid muscle?
Anterior rami of C1-C3
- Carried by a branch of ansa cervicalis
What is the action of the sternohyoid bone?
Depresses the hyoid bone
Which muscles are in the superficial plane of the infrahyoid muscles?
- Omohyoid
2. Sternohyoid
Which muscles are in the deep plane of the suprahyoid muscles?
- Sternothyroid
2. Thyrohyoid
What is the attachment of the sternohyoid muscle?
- Originates from sternum (manubrium) and sternoclavicular joint
- Ascends to insert onto the hyoid bone
What is the innervation of the sternothyroid muscle?
Anterior rami of C1-C3, carried by a branch of ansa cervicalis
What is the action of the sternothyroid muscle?
Depresses the thyroid cartilage
What is the attachment of the sternothyroid muscle?
Arises from the manubrium and attaches to he thyroid cartilage
What is the innervation of the thyrohyoid muscle?
Anterior ramus of C1
- Carried within the hypoglossal nerve
What is the action of thyrohyoid muscle?
Depresses the hyoid bone
- If hyoid bone fixed, elevates the larynx
What is the attachment of the thyrohyoid muscle?
- Arises from thyroid cartilage of larynx
- Ascends to attach to the hyoid bone
What muscles are in the suprahyoid muscles?
- Mylohyoid
- Stylohyoid
- Digastric
- Anterior belly
- Posterior belly - Geniohyoid
What is the arterial supply of the suprahyoid muscles?
Branches of the facial artery
- Occipital artery
- Lingual artery
What is the action of the stylohoid muscle?
Initiates a swallowing action by pulling the hyoid bone in a posterior and superior direction
What is the attachment of the stylohyoid bone?
- Arises from the styloid process of the temporal bone
- Attaches to the lateral aspect of the hyoid bone
What is the innervation of the stylohyoid muscle?
Stylohyoid branch of the facial nerve
- This arises proximally to the parotid gland
What is the action of the mylohyoid muscle?
Elevates the hyoid bone and the floor of the mouth
What is the innnervation of the mylohyoid muscle?
- Inferior alveolar nerve
[A branch of the mandibular nerve (which is derived from the trigeminal nerve)]
What is the attachment of the mylohyoid muscle?
- Originates from the mylohyoid line of the mandible
- Attaches onto the hyoid bone
What is the action of the geniohyoid muscle?
Depresses the mandible and elevates the hyoid bone
What is the attachment of the geniohyoid muscle?
- Arises from the inferior mental spine of the mandible
- Travels inferiorly and posteriorly to attach to the hyoid bone
What is the innervation of the geniohyoid bone?
C1 nerve roots that run within the hypoglossal nerve
What is the action of the digastric muscles?
Depresses the mandible and elevates the hyoid bone
What is the innervation of the anterior belly of the digastric muscles?
Inferior alveolar nerve
[A branch of the mandibular nerve (which is derived from the trigeminal nerve)]
What is the attachment of the anterior belly of the digastric muscles?
- Arises from the digastric fossa of the mandible
- Attaches to intermediate tendon
What is the innervation of the posterior belly of the digastric muscles?
Digastric branch of the facial nerve
What is the attachment of the posterior belly of the digastric muscles?
- Arises from the mastoid process of the temporal bone
- Attaches to intermediate tendon
How are the anterior and posterior bellies of the digastric muscle attached?
Intermediate tendon
- Attached to the hyoid bone via a fibrous sling
What are the 3 ligaments that attach to the hyoid bone?
- Stylohoid ligament
- Thyrohyoid membrane
- Hyoepiglottic ligament
What is the attachment of the stylohyoid ligament?
Extends from the styloid process of the temporal bone to the lesser horn of the hyoid bone
What is the attachment of the thyrohyoid membrane?
- Originates from the superior border of the thyroid cartilage
- Attaches to the posterior surface of the hyoid bone and the greater horns
What is the attachment of the hyoepiglottic ligament?
Connects the hyoid bone to the anterior aspect of the epiglottis
Describe the structure of the hyoid bone
- U shaped structure located in anterior neck
- C3 vertebrae level
- Lies at base of mandible
1. Body - Anterior convex surface
- Posterior concave surface
2. Greater horn - Projects from each end of body in a posterior, superior and lateral direction
- Acts as site of attachment for numerous muscles
3. Lesser horn - Superior aspect of hyoid bone
- Near origin of greater horn
- Projects superoposteriorly (towards the styloid process of the temporal bone)
- Stylohyoid ligament attaches to apex of lesser horn
Which muscles relating to the oral cavity and pharynx attach to the hyoid bone?
- Middle pharyngeal constrictor
- Hyoglossus
- Genioglossus
Which muscles relating to the suprahyoid attach to the hyoid bone?
- Geniohyoid
- Stylohyoid
- Mylohyoid
- Digastric
Which muscles relating to the infrahyoid attach to the hyoid bone?
- Omohyoid
- Sternohyoid
- Thyrohyoind
