1. ANTERIOR TRIANGLE of the NECK

2. Borders Superior: Posterior: Anterior: Mandible.
Sternocleidomastoid (anterior border).
Anterior:
Midline of the neck.

3. Subdivisions Muscular triangle. Submandibular triangle.
Carotid triangle.

4. Contents of Muscular Triangle
Digastric:
Anterior and posterior bellies.
Innervated by two different cranial nerves.
Stylohyoid.
Mylohyoid.

5. Contents of Muscular Triangle
Geniohyoid.
Sternohyoid.
Sternothyroid.
Thyrohyoid.
Omohyoid.

6. Carotid System Common carotid. Bifurcation: Blood monitors:
Carotid sinus:
Dilated terminal portion of common carotid.
Baroreceptor.
Carotid body:
Chemoreceptor.
Internal carotid:
Has no branches in the neck.
External carotid.

7. External Carotid Branches
Superior thyroid (anterior).
Ascending pharyngeal (medial).
Lingual (anterior):
Crossed by hypoglossal nerve at its origin.
Facial (anterior).
Occipital (posterior).
Posterior auricular (posterior).
Superficial temporal (terminal).
Maxillary (terminal).

9. Characteristics and Branches of Cervical Plexus
From ventral rami of C1-4.
Hypoglossal nerve (CN XII).
Sensory branches:
Great auricular (C2-3).
Lesser occipital (C2(3)):
Ventral ramus of C2.
Greater occipital is dorsal ramus of C2.
Transverse cervical (C2-3).
Supraclavicular (C3-4).

10. Characteristics and Branches of Cervical Plexus
Motor branches:
To prevertebral muscles:
See syllabus.
To levator scapulae muscle (C3-4).
To scalene muscles.
Ansa cervicalis:
Supplies infrahyoid muscles.
Except thyrohyoid.
Phrenic nerve (C3,4,5).

11. Ansa Cervicalis Nerve to geniohyoid: Nerve to thyrohyoid.
C1 via hypoglossal nerve.
Nerve to thyrohyoid.
Superior and inferior roots:
Omohyoid.
Sternothyroid.
Sternohyoid.

12. Deep Neck Subclavian artery: Scalene muscles: Thyroid gland. Trachea.
Review from syllabus.
Scalene muscles:
Thyroid gland.
Trachea.
Esophagus.
Thoracic duct and right lymphatic duct.

13. Deep Neck Branches of vagus nerve: Sympathetic trunk:
Review from syllabus.
Sympathetic trunk:
Ascends on anterior surfaces of longus colli and longus capitis muscles.
Lies posterior to common and internal carotids.
Lies deep to carotid sheath.
Contains preganglionic sympathetic fibers from T1 and T2 and T2 and GVA fibers as well from same levels.

14. Sympathetic Trunk Ganglia
Superior cervical ganglion:
Elongated structure on longus capitis muscle.
At level of C1 and C2.
Postganglionic sympathetic fibers from this ganglion supply all smooth muscles and glands of the head.

15. Sympathetic Trunk Ganglia
Middle cervical ganglion.
Inferior cervical ganglion.
Stellate ganglion:
Fused inferior cervical ganglion and T1 ganglion.