Head & Neck: Posterior & Anterior Triangle

Front 1

Prevertebral fascia

Back 1

Surrounds the posterior part of the neck, which contains the cervical VT and the muscles that move it.

Front 2

Pretracheal fascia

Back 2

Surrounds the anterior part of the neck.

Front 3

Retropharyngeal space

Back 3

The point of separation between the prevertebral and pretracheal fascia. A potential space, referred as the "danger space", because infections spread into this space and pass into the mediastinum.

Front 4

Borders of the posterior triangle

Back 4

Anteriorly by the posterior border of the SCM, posteriorly by superior border of the trapezius, inferiorly by the clavicle.

Front 5

Platysma muscle

Back 5

Superior Att: mandible, skin of the cheek, angle of the mouth, & orbicularis oris muscle.

Inferior Att: superficial fascia of the deltoid & pectoral regions.

Actions: tenses the skin of the neck, depresses the mandible.

Innervation: cervical branch of Facial nerve (CN VII)

Front 6

External jugular vein

Back 6

Begins posterior to the angle of the mandible and crosses the superficial surface of the SCM. Drains into the subclavian vein.

Front 7

Cutaneous branches of cervical plexus (Erb's point)

Back 7

Lesser occipital nerve (C2), great auricular nerve (C2, C3), transverse cervical nerve (C2, C3), supraclavicular nerves (C3, C4)

Front 8

Lesser occipital nerve (C2)

Back 8

Parallels the posterior border of the SCM as it passes superiorly. Supplies the scalp that is immediately posterior to the ear.

Front 9

Great auricular nerve (C2, C3)

Back 9

Crosses the superficial surface of the SCM parallel to the external jugular vein. Supplies the skin of the lower part of the ear, skin of parotid gland, & skin from mandible to mastoid process.

Front 10

Transverse cervical nerve (C2, C3)

Back 10

Runs transversely across SCM and neck. Supplies the skin of the anterior triangle of the neck.

Front 11

Supraclavicular nerves (C3, C4)

Back 11

Pass inferiorly to innervate the skin over the shoulder. Has medial, intermediate, and lateral branches.

Front 12

Spinal accessory nerve (CN XI)

Back 12

Innervates the SCM and trapezius muscle, DOES NOT originate from cervical plexus.

Front 13

Trapezius muscle

Back 13

Superior Att: superior nuchal line, external occipital protuberance, ligamentum nuchae, SP C7- T12.

Inferior Att: lateral third of clavicle and acromion and spine of scapula.

Actions: rotates, elevates (superior part) retracts (middle part) and depresses (inferior part) the scapula.

Innervation: spinal accessory nerve (CN XI)

Front 14

Sternocleidomastoid (SCM)

Back 14

Superior Att: mastoid process, lateral half of superior nuchal line.

Inferior Att: sternal head & clavicular head.

Actions: laterally flexes the head and rotates face to opposite side (unilateral), extends head (bilateral).

Innervation: spinal accessory nerve (CN XI)

Front 15

Borders of anterior triangle

Back 15

Medially by medial plane of neck, laterally by the anterior border of SCM, superiorly by inferior border of mandible.

Front 16

Divisions of anterior triangle

Back 16

Divided by digastric and omohyoid muscles. Muscular triangle, carotid triangle, submandibular, & submental triangle.

Front 17

Hyoid bone

Back 17

Does not articulate with any other bone. At the angle between the floor of the mouth and the superior end of the neck.

Front 18

Laryngeal prominence

Back 18

On thyroid cartilage, known as Adam's apple. An extension of cartilage marking the location of vocal cords.

Front 19

Thyrohyoid membrane

Back 19

Stretches between thyroid cartilage and hyoid bone.

Front 20

Mastoid process

Back 20

On the temporal bone. SCM superiorly attaches here.

Front 21

Styloid process

Back 21

On the temporal bone.

Front 22

Retromandibular vein

Back 22

Joins the external jugular vein superiorly.

Front 23

Posterior auricular vein

Back 23

Joins the external jugular vein superiorly.

Front 24

Communicating vein

Back 24

Connects the common facial vein with the anterior jugular vein along the anterior border of the SCM.

Front 25

Contents of the Muscular triangle

Back 25

Infrahyoid muscles, the thyroid gland, and the parathyroid glands

Front 26

Boundaries of muscular triangle

Back 26

Bounded medially by the median plane of neck, superolaterally by the superior belly of omohyoid muscle, and inferolaterally by the anterior border of SCM.

Front 27

Sternohyoid muscle

Back 27

Superior Att: body of hyoid bone.

Inferior Att: posterior surface of manubrium.

Actions: depresses the hyoid

Innervation: Ansa cervicalis (C1-C3).

Front 28

Omohyoid muscle

Back 28

Superior Att: inferior border of hyoid bone.

Inferior Att: superior border of scapula near suprascapular notch

Actions: depresses and retracts the hyoid.

Innervation: Ansa cervicalis (C1-C3)

Front 29

Sternothyroid muscle

Back 29

Superior Att: oblique line of thyroid cartilage.

Inferior Att: posterior surface of manubrium.

Actions: depresses thyroid cartilage and larynx.

Innervation: Ansa cervicalis (C1-C3)

Front 30

Thyrohyoid muscle

Back 30

Superior Att: inferior border of body and greater horn of hyoid.

Inferior Att: oblique line of thyroid cartilage.

Actions: depresses hyoid & elevates the thyroid cartilage and larynx.

Innervation: C1 via hypoglossal nerve (CN XII)

Front 31

Digastric muscle

Back 31

Superior Att: digastric fossa of mandible (anterior belly)

Inferior Att: mastoid process (posterior belly)

Actions: elevates hyoid and depresses mandible.

Innervation: trigeminal nerve (CN V3), Facial nerve (CN VII)

Front 32

Stylohyoid muscle

Back 32

Superior Att: styloid process.

Inferior Att: body of hyoid

Actions: elevates hyoid

Innervation: Facial nerve (CN VII)

Front 33

Mylohyoid muscle

Back 33

Superior Att: mylohyoid line of mandible (lateral attachment)

Inferior Att: hyoid bone and mylohyoid raphe

Actions: supports the floor of the oral cavity

Innervation: trigeminal nerve (CN V3)

Front 34

Ansa cervicalis

Back 34

Innervates 3/4 infrahyoid muscles. Superior branch (C1), inferior branch (C2, C3)

Front 35

Thyroid gland

Back 35

Located at vertebral levels C5-T1. Has a right and left lobe connected by the isthmus which crosses the anterior surface of tracheal rings 2 & 3.

Front 36

Contents of Submandibular triangle

Back 36

Submandibular gland, facial artery & vein, stylohyoid muscle, part of hypoglossal nerve, & lymph nodes.

Front 37

Boundaries of submandibular triangle

Back 37

Superiorly by inferior border of mandible, anteroinferiorly by anterior belly of digastric muscle, posteroinferiorly by the posterior belly of digastric muscle

Front 38

Facial artery/vein

Back 38

Cross over the margin of the body of mandible. Artery is more tortuous than vein and courses more anteriorly.

Front 39

Intermediate tendon

Back 39

The two bellies of digastric muscle attach to each other by this tendon.

Front 40

Hypoglossal nerve (CN XII)

Back 40

Courses lateral to the carotid arteries. Enters submandibular triangle deep to the posterior belly of digastric and mylohyoid muscle, then enters floor of mouth.

Front 41

Submental triangle

Back 41

Contents are the submental lymph nodes. Bounded inferiorly by hyoid bone and anterior bellies of right and left digastric muscles.

Front 42

Carotid triangle

Back 42

Contents are the carotid arteries (common, internal, & external), part of hypoglossal nerve (CN XII), & branches of vagus nerve (CN X).

Front 43

Internal branch of superior laryngeal nerve

Back 43

Supplies sensory fibers to mucosa of the larynx above the level of the vocal cords.

Front 44

External branch of superior laryngeal nerve

Back 44

Joins the the internal branch to form the superior laryngeal nerve

Front 45

Superior laryngeal nerve

Back 45

Formed by the internal and external branches.

Front 46

Cricothyroid muscle

Back 46

Innervated by the external branch of the superior laryngeal nerve

Front 47

Carotid sheath

Back 47

Contains common carotid artery, internal carotid artery, internal jugular vein, and vagus nerve (CN X).

Front 48

Internal jugular vein

Back 48

Located lateral to the common carotid.

Front 49

Tributaries of the internal jugular vein

Back 49

Common facial vein, superior thyroid vein, and middle thyroid vein

Front 50

External carotid artery

Back 50

Superior bifurcation of the common carotid artery.

Front 51

Superior thyroid artery

Back 51

Arises from the anterior surface of the external carotid artery.

Front 52

Superior laryngeal artery

Back 52

A branch of the superior thyroid artery, which pierces the thyroid membrane together with the internal branch of the superior laryngeal nerve.

Front 53

Lingual artery

Back 53

Located superior to the superior thyroid artery off the anterior surface of the external carotid artery.

Front 54

Occipital artery

Back 54

On the posterior surface of the external carotid artery. Supplies blood to part of the scalp.

Front 55

Posterior auricular artery

Back 55

Located superior to the origin of the occipital artery

Front 56

Carotid sinus

Back 56

A dilation of the internal carotid artery near it's origin.

Walls contain baroreceptors that monitor blood pressure.

Innervated glossopharyngeal nerve (CN IX) and vagus nerve (CN X).

Front 57

Carotid body

Back 57

Located on the medial aspect of the carotid bifurcation.

A small mass of nerve tissue that contains chemoreceptors to monitor changes in O2 & CO2 concentration of the blood.

Innervated by the glossopharyngeal nerve (CN IX) and the vagus nerve (CN X).

Front 58

Ascending pharyngeal artery

Back 58

Arises from medial surface of the external carotid artery, close to the bifurcation of common carotid artery.

Front 59

Vagus nerve (CN X)

Back 59

Within the carotid sheath where it lies between and posterior to the common carotid artery and the internal jugular vein.

Front 60

6 branches of the External carotid artery in the Carotid triangle.

Back 60

1) superior thyroid artery

2) superior laryngeal artery

3) lingual artery

4) facial artery

5) occipital artery

6) posterior auricular artery

Front 61

Pyramidal lobe of Thyroid gland

Back 61

Extends superiorly from the isthmus. Remnant of embryonic development, shows the route of descent of the thyroid gland.

Front 62

Left/right recurrent laryngeal nerves

Back 62

Pass posterior to the lobes of the thyroid gland in the groove between the trachea and esophagus.

Front 63

Parathyroid glands

Back 63

Darker in color and harder in structure than the thyroid gland. Usually 1-3 on each side of gland. Play an important role Ca2+ metabolism.

Front 64

Subclavian artery

Back 64

On the right side it is a branch of the brachiocephalic trunk, but on the left side it is a branch of the aortic arch. Has 3 parts.

Front 65

1st part of the subclavian artery

Back 65

Vertebral artery, internal thoracic artery, & thyrocervical trunk. Origin to the medial border of the anterior scalene muscle.

Front 66

Vertebral artery

Back 66

Passes superiorly between anterior scalene and longus colli muscles until it enters the transverse foramen of vertebra C6.

Front 67

Internal thoracic artery

Back 67

Arises from the anteroinferior surface of the subclavian artery and passes inferiorly to supply the anterior thoracic wall.

Front 68

Thyrocervical trunk

Back 68

Arises from the anterosuperior surface of the subclavian artery.

Front 69

What are the 3 branches of the thyrocervical trunk?

Back 69

Transverse cervical artery, suprascapular artery, inferior thyroid artery.

Front 70

Transverse cervical artery

Back 70

Branches off the thyrocervical trunk. Runs deep to omohyoid muscle and supplies the trapezius.

Front 71

Suprascapular artery

Back 71

Branches off the thyrocervical trunk. Passes superiorly to the transverse scapular ligament, supplies the supraspinatus & infraspinatus muscles.

Front 72

Inferior thyroid artery

Back 72

Branches off the thyrocervical trunk, which passes medially towards the thyroid gland.

Front 73

Ascending cervical artery

Back 73

Branch off the inferior thyroid artery.

Front 74

2nd part of the subclavian artery

Back 74

Lies posterior to the anterior scalene muscle and has one branch, Costocervical trunk.

Front 75

Costocervical trunk

Back 75

The only branch point off the 2nd part of the subclavian artery. Arises from the posterior surface and divides into the deep cervical artery & supreme Intercostal artery.

Front 76

3rd part of the subclavian artery

Back 76

Has one branch, the dorsal scapular artery. Between the lateral border of the anterior scalene muscle and the lateral border of the 1st rib.

Front 77

Dorsal scapular artery

Back 77

Passes superior to the middle trunk of the brachial plexus to supply the rhomboid muscles and levator scapulae.

Front 78

Thoracic duct

Back 78

On the left side ascends from thorz into the neck. Joins the venous system near the left venus angle (junction of the left internal jugular vein & the left subclavian vein).

Front 79

Right lymphatic duct

Back 79

Drains into the right venus angle (junction of the right subclavian vein & the right internal jugular vein).

Front 80

Phrenic nerve

Back 80

Crosses the anterior surface of the anterior scalene muscle. Arises from C3-C5 and innervates the diaphragm.

Front 81

Anterior scalene muscle

Back 81

Superior Att: TP of C4-C6.

Inferior Att: 1st rib

Actions: flexes neck, elevates 1st rib during inspiration.

Innervation: anterior Rami C4-C6.

Front 82

Middle scalene muscle

Back 82

Superior Att: posterior tubercles of TP of C2-C7.

Inferior Att: 1st rib

Actions: flexes neck & elevates 1st rib during inspiration.

Innervation: anterior Rami C2-C6

Front 83

Posterior scalene muscle

Back 83

Superior Att: posterior tubercles of TP of C4-C6.

Inferior Att: 2nd rib

Actions: flexes neck laterally, elevates 2nd rib during inspiration. Innervation: anterior Rami C7-C8.