Anterior Muscles of the Neck- Suprahyoid and Infrahyoid Flashcards
Anterior belly of the digastric muscle innervation
mylohyoid branch of the inferior alveolar n. (mandibular branch of the trigeminal nerve–> CN V(3))
-branches of the trigeminal nerve include: 1. ophthalmic, 2. maxillary, 3. mandibular
Anterior belly of the digastric muscle attachments
digastric fossa of the mandible–> intermediate tendon
greater cornu of hyoid) (inf. border of the mandible near symphysis to int. tendon and body and cornu of hyoid
Anterior belly of the digastric muscle actions
depression of mandible bone, elevation of hyoid bone
Posterior belly of the digastric muscle innervation
facial nerve (CN VII)
Posterior belly of the digastric muscle attachments
inferior genial tubercle of the mandible–> anterior aspect of the body of the hyoid bone
(median ridge of mandible to body of hyoid)
Posterior belly of the digastric muscle function
depression of the mandible or elevation of the hyoid
Name the 4 suprahyoid muscles of the anterior neck
- digastric
- anterior belly
- posterior belly
- mylohyoid
- geniohyoid
- stylohyoid
Mylohyoid muscle innervation
mylohyoid branch of the inferior alveolar n. (from CN V(3) - mandibular branch of the trigeminal nerve)
—> * anterior belly of the digastric muscle is also innervated by the same nerve - two muscles are located adjacent to one another
–> mylohyoid muscle is directly deep to the anterior belly of the digastric muscle
Mylohyoid muscle attachments
mylohyoid line of the mandible —> midline raphe and anterior aspect of the body of the hyoid
Mylohyoid muscle actions
elevation of the floor of the oral cavity
Geniohyoid muscle innervation
ventral ramus of C1 spinal nerve via CN XII
(via hypoglossal nerve)
- same innervation as thyrohyoid muscle (an infrahyoid muscle)
Geniohyoid attachments
(deep to the other neck muscles)
inferior genial tubercle of the mandible—> anterior aspect of the body of the hyoid (median ridge of mandible to body of hyoid)
Function of the geniohyoid
elevation of tongue, elevation of hyoid, depression of mandible
Stylohyoid innervation
facial nerve - CN VII
** posterior belly of the digastric muscle is also innervated by the facial nerve
Stylohyoid attachments
styloid process of the temporal bone —> body of the hyoid bone
Stylohyoid innervation
facial nerve CN VII
Name the 4 infrahyoid muscles that are present in the anterior neck:
- omohyoid
- superior belly
- inferior belly
- sternohyoid
- sternothyroid
- thyrohyoid
Superior belly of the omohyoid muscle- innervation
ansa cervicalis (C1-3)
inferior belly of the omohyoid muscle- attachments
superior border of the scapula medial to the scapular notch –> lateral aspect of the hyoid through an intermediate tendon sling that is loosely associated with the clavicle and 1st rib
Superior belly of the omohyoid muscle- function
depression of the hyoid bone
Inferior belly of the omohyoid muscle- innervation
ansa cervicalis (C1-3)
Inferior belly of the omohyoid muscle - attachments
superior border of the scapula medial to the scapular notch –> lateral aspect of the hyoid through an intermediate tendon sling that is loosely associated with the clavicle and 1st rib
Inferior belly of the omohyoid- function
depression of the hyoid bone
Sternohyoid muscle- innervation
ansa cervicalis (C1-3)
Sternohyoid muscle- attachments
posterior side of the proximal clavicle & adjacent manubrium –> the inferior border of body of the hyoid
sternohyoid muscle- actions
depresses the hyoid
Sternothyroid- innervation
ansa cervicalis (C1-3)
Sternothyroid- attachments
from the posterior aspect of the manubrium & costal cartilage of 1st rib –> the thyroid lamina
Sternothyroid- function
depression of an elevated larynx
Thyrohyoid innervation
C1 spinal nerve via CN XII - hypoglossal nerve
Thryohyoid attachments
from the thyroid lamina to the greater horn of the hyoid bone
Thyrohyoid function
depression of hyoid
elevation of the thyroid cartilage
