Anterior Triangle

Question 1

Borders of Anterior Cervical triangle

Answer 1

Inferior boundary (apex) -Jugular notch in the manubrium of the sternum
Anterior boundary - Midline of the neck from chin to the jugular notch
Posterior boundary - The anterior margin of Sternocleidomastoideus
Superior boundary (base) -The lower border of the body of the mandible, and a line extending from the angle of the mandible to the mastoid process
Roof of triangle - superficial fascia, platysma and skin

Question 2

Submandibular (digastric) triangle

Answer 2

Bounded superiorly by the inferior border of the mandible. Laterally by posterior belly of digastric, medially by anterior belly of digastric. Floor formed by mylohyoid and hypoglossal muscles. Contents include submandibular gland and ganglion(parasympathetic ganglion). Submandibular lymph nodes lie superficial to the submandibular gland, Hypoglossal - CN XII, facial a & v.

Question 3

Submental Triangle

Answer 3

Located at the anterior midline of the neck above the hyoid. Bounded by inferiorly by hyoid bone, laterally by anterior bellies of digastric m, floor is mylohyoid m (two join in middle and form a raphae. Contents include submental lymph nodes, beginning of the anterior jugular veins.

Question 4

Carotid Triangle

Answer 4

Most important triangle, lies anterior to superior part of SCM, infrahyoid muscles do not overlap the carotid arteries. Bounded anteriorly by superior belly of omohyoid, superiorly posterior belly of digastric, laterally anterior border of SCM. Contents include Carotid sheath(Deep Fascia) which includes the vagus nerve posteriorly, common carotid medially and ICA after branching, and internal jugular vein laterally.

Question 5

Muscular Triangle

Answer 5

Lies below the hyoid bone. Bounded anteriorly midline of the neck, laterally by superior belly of omohyoid, inferiorly by anterior border of SCM. Contents include thyroid and parthyroid glands-located at C6 vertebral level. Infrahyoid muscles covered by deep cervical fascia. Sternothyroid,sternohyoid,thyrohyoid,and omohyoid (superior and inferior bellies).

Question 6

Common Carotid Artery

Answer 6

In carotid sheath, Right is branch of brachiocephalic trunk, LCC a branches off aorta, branches at C5 - superior border of thyroid cartilage.

Question 7

Internal Carotid Artery

Answer 7

Contains Carotid Sinus(innervated by CN IX and X. acts as a receptor for monitoring arterial blood pressure)

Question 8

External Carotid Artery

Answer 8

terminates in the parotid gland by bifurcating into superficial temporal and maxillary arteries. while traveling superiorly it branches into superior thyroid artery, ascending pharyngeal, lingual, facial, occipital, posterior auricular.

Question 9

Subclavian Artery

Answer 9

Right SC originates from brachiocephalic, LSC from Aorta. each artery is divided into three parts by anterior scalene m. 1st part extends from SC origin to medial border of anterior scalene and branches into vertebral a, internal thoracic a, thyrocervical trunk(branches into transverse cervical,suprascapular,inferior thyroid). 2nd part is located posterior to anterior scalene, gives rise to costocervical trunk. 3rd part extends from the lateral border of anterior scalene to first rib, gives rise to dorsal scapular artery.

Question 10

Veins of anterior triangle

Answer 10

Internal Jugular Vein, anterior jugular, subclavian vein

Question 11

Internal Jugular vein

Answer 11

Begins outside the skull at the external surface of jugular foramen as a dilated structure known as jugular bulb, descends into carotid sheath, terminates by joining Subclavian vein to from brachiocephalic vein.

Question 12

Anterior jugular vein

Answer 12

Begins in the submental triangle below the mandible, descends along the anterior midline of neck, drains into external jugular vein.

Question 13

Nerves of the Anterior Triangle

Answer 13

Vagus nerve, ansa cervicalis, hypoglossal Nerve, sympathetic trunk,

Question 14

Vagus Nerve

Answer 14

longest cranial nerve, exits the skull through the jugular foramen and enters the carotid sheath. Vagus nerve gives rise to the following main branches: recurrent laryngeal, contribution to the pharyngeal plexus, cardiac branches, superior laryngeal.

Question 15

Ansa Cervicalis

Answer 15

motor component of the cervical plexus

Question 16

Sympathetic Trunk

Answer 16

Begins at level of C1, superior cervical ganglion - largest, located at about level of C1/C2, middle cervical ganglion - located at level of cricoid cartilage(C6), and inferior cervical ganglion(sometimes fused with thoracic ganglion and known as stellate ganglion) - located at C7(superior border of 1st rib

Question 17

Ansa Cervicalis

Answer 17

C1,C2,C3. superior Ramus - C1,C2. Inferior Ramus - C2,C3. Branches supply strap muscles of neck (sternoyoid,sternothyroid, superior and inferior bellies of omohyoid). C1 fibers which contribute to superior ramus only supply the thyrohyoid and geniohyoid muscles.

Question 18

Phrenic nerve

Answer 18

C3,C4,C5. motor supply to diaphragm. sole motor nerve to it. also supplies pericardium and part of pleura. sensory to central part of diaphragm. damage will cause paralysis to 1/2 the diaphragm on affected side.