Anterior Neck Flashcards
Which cartilages inferior to the hyoid bone are “true rings” and which are “V-shaped”?
- Thyroid cartilage: V-shaped
- Cricoid cartilage: True ring
What are the borders of the anterior triangle of the neck?
- Anterior: anterior median line
- Posterior: SCM
- Superior: inferior border of mandible
- Apex: jugular notch
- Roof: Sub-Q fascia & platysma
- Floor: pharynx, larynx, thyroid gland (covered by pretrachial fascia)
Mylohyoid m: OIIA?
Suprahyoid
Origin: mylohyoid line of mandible
Insertion: Medial raphe and body of mandible
Innervation: Nerve to the mylyhyoid of V3 (also innervates ant belly of digastric)
Action: Elevates hyoid bone, base of tongue, floor of mouth; depresses mandible
Digastric m: OIIA?
Suprahyoid
Origin: Ant-digastric fossa of mandible; post-mastoid notch of temporal bone
Insertion: Intermediate tendon attached to body of hyoid
Innervation: Ant-nerve to mylohyoid (CN V3); post-Facial n. (CN VII)
Action: Stablizes, raises, anterior movement (ant belly) and posterior movement (post belly) of the hyoid
Geniohyoid m: OIIA?
Suprahyoid
Origin: Genial tubercle of mandible
Insertion: Hyoid bone (deep to mylohyoid)
Innervation: Nerve to geniohyoid (C1, runs w/hypoglossal CN XII)
Action: Raises hyoid bone, depresses mandible
Stylohyoid m: OIIA?
Suprahyoid
Origin: Styloid process
Insertion: Hyoid bone
Innervation: Facial n. (CN VII)
Action: Elevates hyoid b. and base of tongue
Sternohyoid m: OIIA?
Infrahyoid
Origin: Posterior aspect of manubrium (of sternum)
Insertion: Hyoid
Innervation: Ansa cervicalis (C1-C3)
Action: Depresses larynx and hyoid bone, steadies hyoid bone (during vocalization & depression of mandible)
Sternothyroid m: OIIA?
Infrahyoid
Origin: Manubrium (posterior to sternohyoid)
Insertion: Thyroid cartilage (oblique line)
Innervation: Ansa cervicalis (C1-C3)
Action: Depresses larynx and thyroid cartilage (stabilizes it during vocalization and depression of mandible)
Thyrohyoid m: OIIA?
Infrahyoid
Origin: Thyroid cartilage (oblique line)
Insertion: Hyoid bone
Innervation: Nerve to the thyrohyoid (C1, travels w/hypoglossal CN XII)
Action: Depresses larynx and hyoid bone, elevates thyroid cartilage (stabilizes both during vocalization)
Omohyoid m: OIIA? (sup and inf bellies)
Infrahyoid
Origin: Superior border of scapula (near scapular notch)
Insertion: Hyoid bone (jcn of body and greater horn)
Innervation: Innervation: Ansa cervicalis (C1-C3)
Action: Depresses hyoid bone and may stabilize it from below
What 2 mm. appear as 1 going from the manubrium to the hyoid b. but actually start and stop at the thyroid cartilage?
Sternothyroid m. –> Thyrohyoid m.
different innervations
The hyoid bone aids mainly in what 3 actions?
Tongue movement, vocalization, swallowing
During swallowing, infrahyoid mm. ___________ while suprahyoid mm. ___________.
Relax (infrahyoids); Contract (suprahyoids)
What are the 5 major contents of the submandibular triangle?
Submandibular gland Submandibular lymph nodes Mylohyoid n. (V3) Facial a. Lingual n. (can't see it) Hypoglossal n. (CN XII)
What are the 3 branches of the aortic arch?
BCS
- Brachiocephalic Trunk
- Left Common Carotid a.
- Left Subclavian a.
What does the brachiocephalic trunk branch into?
Right common carotid a. and right subclavian a.
The common carotid a. divides into:
Internal and external carotid aa. (enters skull via carotid foramen)