Anterior Triangle of the Neck and Root of the Neck

Question 1

Anterior Cervical Triangle

Answer 1

Wraps around to lateral side of neck, contains platysma m.
Boundaries: midline of the neck (anterior), anterior border of SCM (posterior), inferior border of mandible (superior), jugular notch of manubrium (inferior/apex), subcutaneous tissue with platysma m. (roof), pharynx/larynx/thyroid gland (floor)
Contents: muscles, veins, arteries, nerves, cervical viscera

Question 2

Veins of the Neck

Answer 2

Retromandibular v.
- Formed by superficial temporal v. & maxillary v.
- Divides into anterior & posterior divisions:
o Anterior division + facial v. = common facial v. (drains into interval jugular v.)
o Posterior division + posterior auricular v.= external jugular vein

Clinical Correlation: central line catheterization can go into the subclavian vein or internal jugular vein

Question 3

Suprahyoid mm.

Answer 3

Action: elevate hyoid bone
Postion: superior to hypoid bone
Include: stylohoid m., digastric m., mylohyoid m., geniohyoid m.

Question 4

Infrahyoid mm.

Answer 4

Action: depresses hyoid bone
Postion: inferior to hyoid bone
Include: omohyoid m., sternohyoid m., thyrohyoid m., sternothyroid m.

Question 5

Stylohyoid m.

Answer 5

O: styloid process
I: hyoid bone
Inn: facial n. (CN VII)
Action: Pulls hyoid bone upward in posterosuperior direction
Elevation of hyoid

Question 6

Diagastric m.

Answer 6

O: Ant. Belly: digastric fossa (lower inside of mandible)
Post. Belly: mastoid notch (medial side of mastoid process of temporal bone)
I: hyoid bone
Inn: Ant. Belly: N. to mylohyoid
Post. Belly: Facial n. (CN VII)
Action: Mandible flexed- raises hyoid
Hyoid bone fixed- opens mouth by lowering mandible

Question 7

Mylohyoid m.

Answer 7

O: mylohyoid line
I: hyoid bone
Inn: N. to mylohoid (off inferior alveolar n. from mandibular division of trigeminal n. V3)
Action: supports and elevates floor of mouth; elevates hyoid

Question 8

Geniohyoid m.

Answer 8

O: inferior mental spine of mandible
I: hyoid bone
Inn: N. to geniohyoid; Branch from anterior ramus of C1 via hypoglossal n. (CN XII)
Action: Mandible fixed- elevates and pulls hyoid forward
Hyoid fixed- pulls mandible downward and inward

Question 9

Sternohyoid m.

Answer 9

O: SC joint & manubrium of sternum
I: hyoid bone
Inn: Anterior rami of C1-C3 via ansa cervicalis
Action: Depresses hyoid bone after swallowing

Question 10

Omohyoid m.

Answer 10

O: scapula
I: hyoid bone
Inn: Anterior rami of C1-C3 via ansa cervicalis
Action: Depresses and fixes hyoid bone

Question 11

Thyrohyoid m.

Answer 11

O: throid cartilage
I: hyoid bone
Inn: Fibers from anterior ramus of C1 carried via hypoglossal n. (CN XII)
N. to thyrohyoid m.
Action: Depresses hyoid bone and raises larynx

Question 12

Sternothyroid m.

Answer 12

O: manubrium of sternum
I: thyroid cartilage
Inn: Anteior rami of C1-C3 via ansa cervicalis
Action: Draws larynx downward

Question 13

Muscular Triangle

Answer 13

Contents:
- Muscle: omohyoid m., sternohyoid m., sternothyroid m., thyrohyoid m.
- Viscera: thyroid gland, parathyroid glands, trachea, esophagus, esophagus, common carotid a., internal jugular v.

Question 14

Submental

Answer 14

Contents:
- Mylohyoid m., submental lymph nodes, some small veins

Question 15

Submandibular (Digastric) Triangle

Answer 15

Contents:
- Submandibular gland
- Submandibular lymph nodes
- Marginal mandibular branch of facial n. (CN VII)- supplies mm. of facial expression
- Hypoglossal n. (CN XII)
- Mylohyoid n. (of CN V3)- supplies mylohyoid m. & anterior belly of digastric m.
- Facial a. & v.

Question 16

Carotid Triangle

Answer 16

Contents:
- Nerves: Acessory (CN XI), Vagus (CN X), Hypoglossal (CN XII), Ansa cervicalis (C1-C3), Larygeal nn. (CN X branches)
- Arteries: common, internal & external carotid aa., 6 branches of ext. carotid a. (3 ant. & 3 post.)
- Veins: all branches have accompanying vv. Draining into IJV

Question 17

Carotid Sheath

Answer 17

Contents:
- Carotid artery- common carotid artery, internal carotid artery (carotid sinus)
- Internal jugular vein
- Vagus nerve (CN X)

Question 18

3 Anterior External Carotid Artery Branches

Answer 18

Superior thyroid a.
Lingul a.
Facial a.

Question 19

3 Posterior External Carotid Artery Branches

Answer 19

Ascending pharyngeal a.
Occipital a.
Posterior auricular a.

Question 20

External carotid a. terminates as:

Answer 20

Superficial temporal a. and maxillary a.

Question 21

Ansa Cervacalis

Answer 21

Nerve loop formed from anterior rami of cervical n. C1-C3
-Innervates infrahyoid mm.
-Superior root- mainly of C1 fibers from anterior rami
-Inferior root- anterior rami of C2 & C3

Question 22

Neurovasculature

Answer 22

• Superior thyroid artery runs with external larygeal nerve
• Superior larygeal artery runs with internal larygeal nerve
  Both external and interal laryngeal nn. are branches of the superior laryngeal n. (branch of vagus n. CN X)
• Superior thyroid artery gives rise to the superior larygeal a.

Question 23

Root of the Neck

Answer 23

Junction between thorax and neck
Includes phrenic n., right vagus n., left vagus n., right recurrent laryngeal n., left recurrent laryngeal n.

Question 24

Roots of Neck Vascular

Answer 24

Vertebral artery is deep and sizable
- Thyrocervical trunk gives rise to suprascapular a., transverse cervical a., and
- Second portion: costocervical trunk
- Transverse cervical bifurcates into superficial and deep

Question 25

Vertebral Vessels

Answer 25

Vertebral v. - drains into brahiocephalic v.
Vertebral a. post. to vertebral a. & deep in the neck
-Arises from subclavian a. prior to thyrocervical trunk
-Enters transverse foramen of C6

Question 26

Root of the Neck Lymphatics

Answer 26

Right lymphatic duct
Thoracic duct

Question 27

Prevertebral mm.

Answer 27

Lie directly posterior to retropharyngeal space
- Longus colli & capitis mm.
- Rectus capitis anterior m.
- Anterior scalene m.

Question 28

Cervical Viscera

Answer 28

From anterior to posterior:
1. Thyroid & parathyroid glands
2. Larynx & trachea (inferior)
3. Pharynx & esophagus
Thyroid ima artery is present in about 10% of thyroid glands
Pyramidal lobe is present in about 50% of thyroid glands

Question 29

Horizontal Zones of the Neck

Answer 29

Zone I= thoracic inlet to cricoid cartilage (treated as upper thoracic injury)
Zone II= cricoid cartilage to angle of mandible
Zone III= angle of mandible to base of skull (approach as head trauma)