Bhattacharya 3 Flashcards
Boundaries of the the Anterior Cervical Triangle
- Inferior border of the mandible
- Anterior border of the sternocleidomastoid m.
- Line drawn in the anterior median plane of the neck from the mental
symphysis to the jugular notch
Subdivisions of the Anterior Triangle
- Submental triangle
- Muscular triangle
- Submandibular (digastric) triangle
- Carotid triangle
Boundaries of the Submental Triangle
- Anterior bellies of the digastric m.
a. Origin: Mandible
b. Insertion: Intermediate tendon to the hyoid bone
c. Action: Assists in depressing mandible; raise and steady hyoid bone during
swallowing and speaking
d. Innervation: mylohyoid n. (CN V3) - Hyoid bone
Submental Triangle: Relation to Mylohyoid Muscle
- Deep to submental triangle
- Forms the floor of the mouth
- Origin: Mylohyoid line of the mandible
- Insertion: Hyoid bone
- Action: Elevates hyoid bone, floor of mouth and tongue during swallowing and
speaking - Innervation: mylohyoid n. (CN V3)
Contents of Submental Triangle
Submental lymph nodes
Boundaries of the Muscular Triangle
- Anterior border of the sternocleidomastoid m.
- Superior belly of the omohyoid m.
- Anterior midline of the neck
Muscular Content of the Muscular Triangle
Infrahyoid (strap) muscles
- Omohyoid
- Sternohyoid
- Sternothyoid
- Thyrohyoid
(1) Two bellies, superior and inferior, united by an intermediate tendon connected by a fascial sling to the clavicle
(2) Landmark structure in the neck because it divides both the anterior and posterior triangles into smaller triangles
(3) Origin: Scapula, omo means shoulder in Greek
(4) Insertion: hyoid bone
Omohyoid m.
- Most superficial
- Origin: manubrium
- Insertion: body of hyoid bone
Sternohyoid m.
- Deep to sternohyoid m.
- Origin: Manubrium
- Insertion: thyroid cartilage
Sternothyroid m.
(1) Appears to be the superior continuation of the sternothyroid
(2) Origin: thyroidcartilage
(3) Insertion: hyoidbone
(4) Innervated by C1
Thyrohyoid m.
Collective action of the infrahyoid muscles
Anchor the hyoid bone and depress the hyoid and larynx during swallowing and speaking
Innervation of the infrahyoid muscles
a. Branches of the ansa cervicalis (except thyrohyoid muscle)
b. Ansa cervicalis is a loop of nerve fibers derived from the cervical plexus
c. Cervical plexus is a somatic nerve plexus derived from the ventral
primary rami of C1 through C4
Visceral Content of the Muscular Triangle
Thyroid and parathyroid glands, esophagus, and trachea
Boundaries of Submandibular Triangle
- Inferior border of the body of the mandible
- Anterior belly of the digastric m.
- Posterior belly of the digastric m.
a. Origin: Mastoid notch of temporal bone
b. Insertion: Intermediate tendon to the hyoid bone
c. Action: Same as anterior belly of the digastric m.
d. Innervation: Facial n. (CN VII)
Posterior belly of the digastric m.
Contents of the Submandibular Triangle
- Submandibular gland and lymph nodes
- Facial artery, a branch of the external carotid a., sends branches to the
submandibular gland and the submental a. to the mylohyoid m. - Facial vein joins the anterior division of the retromandibular vein and drains into
the common facial v. and then into the internal jugular v. - Marginal mandibular branch of the facial nerve
- Mylohyoid n., a branch of the trigeminal n.
- Stylohyoid m.
- Hypoglossal nerve
a. Splits around the intermediate tendon of the digastric m. and partially covers the posterior belly
b. Origin: Styloid process of the temporal bone
c. Insertion: Hyoid bone
d. Action: Elevates and retracts the hyoid bone
e. Innervation: Facial n. (CN VII)
Stylohyoid m.
Lies superficial to the hyoglossus m. and deep the mylohyoid m.
Hypoglossal nerve
Boundaries of the Carotid Triangle
- Posterior belly of the digastric m.
- Superior belly of the omohyoid m.
- Anterior border of the sternocleidomastoid m.
Contents of the Carotid Triangle
- Carotid Sheath
- Deep cervical lymph nodes
- Ansa cervicalis
- Hypoglossal n.
- Sympathetic chain
- Branches of the external carotid artery within the carotid triangle
- Superior Laryngeal Nerve of the Vagus
- A tubular sheath of connective tissue that encloses the common carotid (below C3) and the internal carotid (above C3) arteries, the internal jugular vein and vagus nerve.
- Attached superiorly to the skull around the jugular foramen and the carotid canal
- Blends inferiorly with the adventitia of the great vessels in the superior mediastinum
Carotid Sheath
In the _______, the ______ is a chemoreceptor located within the bifurcation of the common carotid arteries which responds to changes in pCO2 and pO2.
(Afferent fiber from the carotid sinus branch of the glossopharyngeal n. (CN IX))
- Common carotid artery
- Carotid body
In the ______, the ______ is the dilated portion of the origin of the internal carotid artery and the distal termination of the common carotid artery that functions as a pressure or baroreceptor.
(Afferent fiber from the carotid sinus branch of the glossopharyngeal n. (CN IX))
- Internal carotid artery
- Carotid sinus
a. Located on or slightly embedded in the anterior surface of the carotid sheath
b. Superior root – C1
c. Inferior root – C2,3
Ansa cervicalis
a. Embedded in anterior surface of the carotid sheath
b. Passes deep to the stylohyoid and the posterior belly of the digastric
Hypoglossal n. (CN XII)
Located posterior to the carotid sheath
Sympathetic chain
Branches of the external carotid artery within the carotid triangle
- Superior thyroid a.
- Ascending pharyngeal a.
- Lingual a.
- Facial a.
- Occipital a.
Branch of the superior thyroid artery that enters larynx through the thyrohyoid membrane
Superior laryngeal a.
- Lowest branch, sometimes arising from the common
carotid or external carotid a. - Arches caudally towards the thyroid gland
Superior thyroid a.
(1) Small branch generally arising from the medial aspect of the external carotid near the bifurcation of the common carotid a.
(2) May arise at variable points along the external carotid artery
Ascending pharyngeal a.
(1) Arises at the level of the greater horn of the hyoid bone
(2) Passes deep to the hyoglossus m.
Lingual a.
(1) Usually arises a short distance above the lingual a.
(2) 20% of the time the facial and lingual arteries will arise from a
common stem
Facial a.
(1) Arises from the posterior aspect of the external carotid a.
(2) Follows the digastric m. medially toward the mastoid process
(3) Crosses deep to the hypoglossal n. (CN XII)
(4) Gives of a small branch to the sternocleidomastoid m. as it crosses the
hypoglossal n.
Occipital a.
Branches of the Superior Laryngeal Nerve of the Vagus
- Internal laryngeal branch of the superior laryngeal n.
2. External branch of the superior laryngeal n.
(1) Enters larynx along with the superior laryngeal artery through the thyrohyoid membrane
(2) Supplies afferent fibers to the mucous membrane of the upper larynx
- Cell bodies located in the inferior
ganglion of the vagus
Internal laryngeal branch of the superior laryngeal n.
(1) Efferent (motor) fibers to the cricothyroid m. of the larynx
- Cell bodies to skeletal muscle of pharyngeal arch origin are located in the nucleus ambiguus
External branch of the superior laryngeal n.
