Anatomy of the Neck Flashcards
What fascia covers the thyroid, trachea and esophagus (visceral compartment)?
Pretracheal fascia
What are the fascia of the neck?
- Superficial fascia
- Investing fascia
- Pretracheal fascia
- Prevertebral fascia
- Carotid sheath
What is the anterior triangle bound by?
- Inferior border of the mandible
- Anterior border of the sternocleidomastoid (SCM)
- Midline of neck
What is on the roof of the anterior triangle?
Deep investing fascia around muscles
What is on the floor of the anterior triangle?
- Pretracheal fascia
- Carotid sheath (posterolaterally)
What are the 4 sub-triangles in the anterior triangle of the neck?
- Submandibular (digastric) triangle
- Submental triangle
- Carotid triangle
- Muscular (omotracheal) triangle
What are the 2 sub-triangles in the posterior triangle of the neck?
- Omoclavicular (supraclavicular) triangle
- Occipital triangle
What is the submandibular triangle bound by?
- Anterior and posterior bellies of digastric
- Body of mandible
What is located within the submandibular triangle?
- Submandibular gland
- Submandibular lymph nodes
- Facial artery (pulse) and vein
- (part of) CN XII
What is the submental triangle bound by?
- Anterior belly of diagastric
- Hyoid
- Midline
What is found within the submental triangle?
Submental lymph nodes
Where can you feel the pulse of the facial artery?
Anteroinferior angle of the masseter muscle against inferior surface of mandible
What are the 2 bellies of the digastric muscle?
- Anterior belly
- Posterior belly
Where does the anterior belly of the digastric muscle originate?
Digastric / Submandibular fossa on lower medial aspect of mandible
Where does the posterior belly of the digastric muscle originate?
Mastoid notch on medial side of mastoid process
Where do both bellies of the digastric muscle insert?
Attachement of their intermediate tendon at hyoid
What are the actions of the digastric muscle?
- Anterior belly raises hyoid and opens mouth by lowering mandible
- Posterior belly elevates and retracts hyoid bone
What is the anterior belly of the digastric innervated by?
Nerve to mylohyoid (V3)
What is the posterior belly of the digastric innervated by?
Digastric branch of VII
What is the mylohyoid derived from?
- Anterior = 1st pharyngeal arch
- Posterior = 2nd pharyngeal arch
What borders the carotid triangle?
- Posterior belly of digastric
- Superior belly of omohyoid and sternocleidomastoid
What are found in the carotid triangle?
- Thyroid gland
- Larynx
- Pharynx
- Carotid sheath (and contents)
- Branches of cervical plexus
- Ansa cervicalis
What is the ansa cervicalis?
- Loop between branches of cervical plexus and hypoglossal nerve
- Superficial to IJV
What are the borders of the omotracheal / muscular triangle?
Superior - hyoid bone
Lateral - superior belly of omohyoid and anterior border of sternocleidomastoid
Medial - midline of neck
What are the borders of the omotracheal / muscular triangle?
- Superior: Hyoid bone
- Lateral: Superior belly of omohyoid and anterior border of SCM
- Medial: Midline of neck
What is contained within the omotracheal triangle?
“Muscular triangle”
- Sternohyoid muscle
- Sternothyroid muscle
- Thyroid gland (part of)
- 1 parathyroid gland
What is the only bone in the body that does not articulate with another bone?
Hyoid
Where are the suprahyoid muscles located?
- Above hyoid
- Connect to skull or mandible
Where are the infrahyoid muscles located?
- Below hyoid
- Connect to inferior structures (sternum, scapula, thyroid cartilage)
When does the hyoid bone move up and own?
Swallowing
Name the suprahyoid muscles
- Mylohyoid
- Digastric
- Stylohyoid
- Geniohyoid
Name the infrahyoid muscles
- Sternohyoid
- Omohyoid
- Thyrohyoid
- Sternothyroid
What is the action of the infrahyoid (strap) muscles?
Depress the hyoid (in actuallity this is mostly done by gravity)
What is the innervation of the infrahyoid (strap) muscles?
- Sternohyoid, omohyoid, sternothyroid by anterior rami of C1-3 (branches of cervical plexus)
- Thyrohyoid by C1, hitchhiking hypoglossal nerve