Unit 1 Triangles & Deep Structures of the Neck Flashcards
What is the anterior boundary of the posterior triangle?
Posterior border of the SCM
What is the posterior boundary of the posterior triangle?
Anterior border of the trapezius
What is the inferior boundary of the posterior triangle?
Superior border of the middle third of the clavicle
What is the superior boundary of the anterior triangle?
Inferior border of the mandible
What is the anterior boundary of the anterior triangle?
Anterior midline
What is the posterior boundary of the anterior triangle?
Anterior border of the SCM
Where is the apex of the anterior triangle located?
Inferiorly at the jugular notch
What is the roof of the anterior triangle formed by?
The investing layer of the deep cervical fascia, the superficial cervical fascia, and the platysma
What are the four subdivisions of the anterior triangle?
Submental, submandibular, carotid, and muscular triangles
Which subdivision of the anterior triangle is unpaired?
Submental
What are the boundaries of the submental triangle?
The left and right anterior bellies of digastric and the body of the hyoid bone
What makes up the floor of the submental triangle?
Mylohyoid muscle
What are the contents of the submental triangle?
Minor veins and lymph nodes
Which subdivision of the anterior triangle must be palpated carefully due to its vital structures?
Submandibular triangle
What are the boundaries of the submandibular (digastric) triangle?
Inferior border of the mandible, anterior belly of digastric, and posterior belly of digastric
What makes up the floor of the submandibular triangle?
Mylohyoid and hyoglossus muscles
What are the contents of the submandibular triangle?
Submandibular gland, internal carotid artery, facial artery, internal jugular vein, glossopharyngeal nerve, and vagus nerve
In what triangle does the common carotid artery bifurcate?
Carotid
What are the boundaries of the carotid triangle?
Posterior belly of digastric, superior belly of omohyoid, and the anterior border of SCM
What makes up the floor of the carotid triangle?
Portions of the thyrohyoid, hyoglossus, and inferior and middle constrictor muscles
What are the contents of the carotid triangle?
Parts of the common and internal carotid arteries the external carotid artery and three of its branches: the superior thyroid artery, lingual artery, and facial artery
What are the boundaries of the muscular triangle?
Superior belly of omohyoid, anterior midline of the neck, and the anterior border of SCM
What makes up the floor of the muscular triangle?
Posterior layer of pretracheal fascia
What are the contents of the muscular triangle?
Sternohyoid and sternothyroid muscles, thyroid gland, trachea, and esophagus
What is the hyoid bone located?
Between the mandible and larynx
What is the forensic significance of the hyoid bone?
Often broken in cases of strangulation
What part of the hyoid bone is the attachment site for the stylohyoid ligament?
Lesser horn
What are the four infrahyoid muscles?
Omohyoid, sternohyoid, sternothyroid, and thyrohyoid
What two infrahyoid muscles make up the superficial layer?
Omohyoid and sternohyoid
What two infrahyoid muscles make up the deep layer?
Sternothyroid and thyrohyoid
What is the origin of omohyoid?
Inferior belly of omohyoid originates from the upper border of the scapula. It ends in an intermediate tendon located deep to the SCM. The superior belly of omohyoid extends upward from this tendon
What is the insertion of omohyoid?
Body of the hyoid
What is the innervation of omohyoid?
Ansa cervicalis (C1-C3)
What is the function of omohyoid?
Depresses the hyoid bone and larynx
What is the origin of sternohyoid?
Posterior surface of the manubrium and the medial end of the clavicle
What is the insertion of sternohyoid?
Body of the hyoid bone
What is the innervation of sternohyoid?
Ansa cervicalis
What is the function of sternohyoid?
Depresses the hyoid bone and larynx
What is the origin of sternothyroid?
Posterior surface of the manubrium, inferior to the origin of the sterohyoid
What is the insertion of sternothyroid?
Oblique line on the lamina of the thyroid cartilage
What is the innervation of sternothyroid?
Ansa cervicalis
What is the function of sternothyroid?
Depresses the larynx
What is the origin of thyrohyoid?
Oblique line on the lamina of the thyroid cartilage
What is the insertion of thyrohyoid?
Body of the hyoid bone
What is the innervation of thyrohyoid?
C1 through hypoglossal nerve
What is the function of thyrohyoid?
Depresses the hyoid bone
Why else do we need all these muscles to depress the hyoid bone and larynx (infrahyoid muscles)?
Swallowing, speech, breathing
If the hyoid bone is fixed, how is the mouth opened?
Digastric depressed the mandible
What are the four subdivisions of the deep cervical fascia of the neck?
Investing layer, pretracheal, prevertebral, and carotid sheath
Which subdivision of the deep cervical fascia encloses the SCM and trapezius?
Investing layer
What subdivision of the deep cervical fascia encloses the thyroid gland, trachea, and esophagus?
Pretracheal
What subdivision of the deep cervical fascia encloses the vertebral column and the deep muscles of the back?
Prevertebral fascia
What does the carotid sheath enclose?
Common carotid artery, internal carotid artery, internal jugular vein, vagus nerve, and deep cervical lymph nodes
What is the function of the fascial layers of the neck?
To provide a slippery surface to reduce friction during gross movements of the head and neck and swallowing
What can happen to the fascial layers of the neck leading to neck pain?
Adhesion of the layers (myofacial release helps with this)
What is the clinical significance of the fascial layers of the neck?
May serve as a channel for infection, cancer of the deep cervical lymph nodes can compress the internal jugular vein (ICP)
Infection in the pretracheal fascia can travel where?
To the mediastinum
What is the superior thoracic aperture (thoracic inlet)?
Opening through which structures of the neck pass into the thorax