Anterior Triangle of the Neck Flashcards
What are the muscles of the Anterior Triangle of the Neck?
Digastric, Mylohyoid, Hyoglossal, Sternothyroid, Omohyoid, Sternohyoid, Thyrohyoid, Stylohyoid, Geniohyoid
What is the origin of the Digastric muscle?
posterior belly: mastoid process
anterior belly: digastric fossa, internal mandible
What is the insertion of the Digastric muscle?
lateral aspect of body of hyoid
What is the nerve supply of the Digastric muscle?
posterior belly: CN VII
anterior bell: Mylohyoid nerve (s) mandibular nerve (m)
What is the blood supply of the Digastric muscle?
anterior belly: submental artery
posterior belly: occipital artery
What is the action of the Digastric muscle?
open mouth by depressing mandible, fixes hyoid bone
What is noteworthy about the Digastric muscle?
derivative of second pharyngeal arch
What is the origin of the Mylohyoid muscle?
inner surface of mandible
What is the insertion of the Mylohyoid muscle?
body of hyoid
What is the nerve supply of the Mylohyoid muscle?
sensory: mylohyoid nerve
motor: mandibular nerve (CN V)
What is the blood supply of the Mylohyoid muscle?
mylohyoid branch of inferior alveolar artery
What is the action of the Mylohyoid muscle?
elevates hyoid bone, raises floor of mouth, depresses mandible when hyoid is fixed
What is noteworthy about the Mylohyoid muscle?
derivative of second pharyngeal arch
What is the origin of the Hyoglossal muscle?
upper border of the greater horn of they hyoid and body of the hyoid bone
What is the insertion of the Hyoglossal muscle?
spreads out into the intrinsic muscles of the tongue
What is the nerve supply of the Hyoglossal muscle?
CN XII (hypoglossal nerve)
What is the blood supply of the Hyoglossal muscle?
lingual artery
What is the action of the Hyoglossal muscle?
depresses the sides of the tongue, retracts the tongue
What is noteworthy about the Hyoglossal muscle?
extrinsic muscle of the tongue
What is the origin of the Sternothyroid muscle?
posterior manubrium
what is the insertion of the Sternothyroid muscle?
thyroid cartilage
What is the nerve supply of the Sternothyroid muscle?
C2 and C3 by a branch of ansa cervicalis
What is the blood supply of the Sternothyroid muscle?
superior thyroid artery
What is the action of the Sternothyroid muscle?
depresses hyoid and larynx
What is the origin of the Omohyoid muscle?
superior belly: hyoid bone
inferior belly: superior scapular border
What is the insertion of the Omohyoid muscle?
superior belly: hyoid bone
inferior belly: clavicle via intermediate tendon
What is the nerve supply of the Omohyoid muscle?
C1-C3 by a branch of ansa cervicalis
What is the blood supply of the Omohyoid muscle?
transverse cervical artery
What is the action of the Omohyoid muscle?
depresses hyoid and larynx
What is noteworthy about the Omohyoid muscle?
intermediate tendon is tethered to the clavicle by a fascial sling
What is the origin of the Sternohyoid muscle?
sternum
What is the insertion of the Sternohyoid muscle?
body of hyoid
What is the nerve supply of the Sternohyoid muscle?
C1-C3 by a branch of ansa cervicalis
What is the blood supply of the Sternohyoid muscle?
superior thyroid artery
What is the action of the Sternohyoid muscle?
depresses hyoid and larynx
What is the origin of the Thyrohyoid muscle?
thyroid cartilage
What is the insertion of the Thyrohyoid muscle?
body of hyoid
What is the nerve supply of the Thyrohyoid muscle?
ansa cervicalis (C1)
What is the blood supply of the Thyrohyoid muscle?
superior thyroid artery
What is the action of the Thyrohyoid muscle?
depresses hyoid
What is noteworthy about the Thyrohyoid muscle?
lies deep to Sternohyoid
What is the origin of the Stylohyoid muscle?
styloid process
What is the insertion of the Stylohyoid muscle?
lateral margin of the hyoid
What is the nerve supply of the Stylohyoid muscle?
stylohyoid branch of CN VII (facial nerve)
What is the blood supply of the Stylohyoid muscle?
ascending pharyngeal artery
What is the action of the Stylohyoid muscle?
pulls hyoid superiorly and posteriorly during swallowing
What is the origin of the Geniohyoid muscle?
inner surface of the mandible
What is the insertion of the Geniohyoid muscle?
body of hyoid
What is the nerve supply of the Geniohyoid muscle?
ansa cervicalis (C1) via hypoglossal nerve (CN XII)
What is the blood supply of the Geniohyoid muscle?
lingual and submental arteries
What is the action of the Geniohyoid muscle?
elevates tongue, depresses mandible, works with mylohyoid
What are the boundaries of the Anterior Cervical Triangle?
anterior midline of neck, inferior border of mandible, anterior border of SCM. Can be divided into four small triangles.
What are the boundaries of the Submandibular Triangle?
mandible, posterior and anterior bellies of digastric muscle. Contains the submandibular gland, ganglion, lymph nodes, CN XII, and facial vein and artery
What are the boundaries of the Submental Triangle?
hyoid bone, anterior bellies of digastric muscle. Contains the beginning of the anterior jugular veins and lymph nodes.
What are the boundaries of the Carotid Triangle?
superior belly of omohyoid muscle, posterior belly of digastric muscle, anterior border of SCM. Contains the carotid sheath (CN X, carotid arteries, internal jugular vein)
What are the boundaries of the Muscular Triangle?
anterior midline of neck, superior belly of omohyoid muscle, anterior border of SCM muscle. Contains thyroid and Parathyroid glands as well as the infrahyoid muscles.
