Anatomy Unit 8: Posterior Triangle And Root Of Neck

Front 1

Mental Symphysis

Back 1

Where left and right mandible join.

Front 2

Location of facial artery

Back 2

At inferior border of mandible near anterior border of masseter muscle.

Front 3

4 Lower limits of Neck

Back 3

jugular notch, sternoclavicular joint, clavicle, and CV7 posrteriorly.

Front 4

Hyoid Bone

Back 4

Located at CV3 inferior to the inferior part of mandible. Has central body and lesser and greater horns. Does not articulate with any other bones but is origin or insertion for neck muscles.

Front 5

Thyroid Membrane

Back 5

Suspends Larynx

Front 6

Thyroid Cartilage

Back 6

Cartilage of larynx; forms adams apple. Inferior and superior horn on each side; shaped like shield. Located inferior to Hyloid bone and superior to cricoid cartilage.

Front 7

Cricoid Cartilage

Back 7

At level of CV 6. Is the beginning of trachea.

Front 8

4 Occurrences at CV 6

Back 8

1) Junction of pharynx with esophagus.
2) Middle cervical sympa. chain ganglion.
3) Vertebral artery enters transverse foramen of CV 6.
4) Junction of Larynx and Trachea

Front 9

Boundaries of Posterior Triangle

Back 9

Anteriorly - Posterior border of Sternocleidomastoid muscle
Posteriorly - Anterior border of Trap
Inferiorly - Clavicle

Front 10

Boundaries of Anterior Triangle

Back 10

Medially - Midline
Superiorly - Inferior border of mandible
Laterally - Anterior border of sternocleidomastoid muscle

Front 11

Superficial Cervical Fascia

Back 11

Fascia encircling neck, contains fat, cutaneous nerves, muscles nerves and veins of facial expression.

Front 12

Nerves of the Cervical Plexus

Back 12

Lesser occipital Nerve (C2), Greater auricular nerve (C2, 3), Transverse Cervical nerve (C2, 3), Supraclavicular Nerve (C3, 4).

Front 13

Lesser Occipital Nerve

Back 13

(C2), Follows posterior border of SCM muscle superiorly to head. Supplies skin of the neck postero-superiorly to the auricle of the ear.

Front 14

Great Auricle Nerve

Back 14

(C2, 3), Courses vertically on the surface of the SCM muscle. Travels anterior to the Lesser Occipital to area anterior of ear. Traveling partners with External Jugular Vein. Supplies skin of parotid region of auricle. Supplies skin of the angle of the mandible and continues to mastoid process.

Front 15

Transverse Cervical Nerves

Back 15

(C2, 3) Cross SCM horizontally. Supplies skin of anterior triangle of neck. Joins cervicle branch of facial nerve inferior to parotid gland.

Front 16

Supraclavicular Nerves

Back 16

(C3, 4) Cross clavicle. Supply skin of inferior half of posterior triangle of neck. Supply skin of upper thoracic region and deltoid regions. Breaks off into anterior, middle, and posterior branches.

Front 17

Platysma Muscle

Back 17

Muscle of facial expression. Extends from the fascia of thoracic region to inferior aspect of mandible. Superficial to external jugular vein and trunks of cutaneous nerves. Is very thin and difficult to separate from superficial cervical fascia. Innervated by the facial nerve (CN 7).

Front 18

External Jugular Vein

Back 18

Formed by union of retromandibular and posterior auricular veins. Runs vertically across SCM muscle from parotid region to antero-inferior part of posterior triangle. Drains into subclavian vein.

Front 19

Investing Layer of Deep Cervical Fascia

Back 19

Anterior layer. Covers both the superficial and the deep surfaces of trap. and SCM muscles (invests them). Attaches to superior nuchal line and clavicle Forms Roof of anterior and posterior triangles of neck.

Front 20

Prevertebral Fascia

Back 20

Posterior layer of deep cervical fascia. Surrounds vertebral column including its closely related muscles.

Front 21

Visceral Fascia

Back 21

Surrounds viscera of neck (pharynx, esophagus, larynx, trachea, and thyroid gland).

Front 22

Carotid Sheath

Back 22

Surrounds carotid vessels, jugular vein, and vagus nerve.

Front 23

Middle Cervical Fascia

Back 23

Surrounds infrahyoid strap muscles.

Front 24

Roof of Posterior Triangle

Back 24

Investing layer of deep cervical fascia.

Front 25

Floor of Posterior Triangle

Back 25

-Splenius capitis and cervicis muscles
-levator scapulas
-posterior, middle, and anterior scalene muscles

Front 26

Carpet of Posterior Triangle

Back 26

Prevertebral Fascia

Front 27

Sternocleidomastoid Muscle (SCM)

(location, origin, insertion, job, innervation)

Back 27

-Anterior border of posterior triangle.
-Origin is manubrium and medial end of clavicle
-Insertion is mastoid process
-Contraction of one muscle turns head to opposite side, both flexes neck, accessory muscle of respiration.
-Innervation is Accessory Nerve (CN11) and C2, 3.

Front 28

Scalene Muscles

Back 28

3 muscles which help make up the floor of the posterior triangle. Innervated by cervical nerves, are muscles of inspiration, act on vertebral column. Anterior, middle, and posterior.

Front 29

Anterior Scalene Muscle
(origin, insertion, innervation)

Back 29

Origin - anterior tubercle of transverse process of CV3 - 6.
Inserts - scalene tubercle of first rib between grooves for subclavian vessels.
Innervated - C5 - 7.

Front 30

Location of Phrenic Nerve in Posterior Triangle

Back 30

Crosses anterior surface of Scalene anterior muscle deep to the prevertebral fascia. Enters superior thoracic aperture.

Front 31

Middle Scalene Muscle
(origin, insertion, innervation)

Back 31

Largest of 3 scalene muscles.
Origin - Posterior tubercle of transverse process of CV2 - 7.
Insertion - Superior surface of first rib immediately posterior to brachial plexus and subclavian artery.
Innervation - C3-8

Front 32

Posterior Scalene Muscle
(origin, insertion, innervation)

Back 32

Smallest scalene muscle.
Origin - Posterior tubercle of transverse process of CV 5-7
Insertion - 2nd rib
Innervation - C7-8

Front 33

Location of Primary Ventral Rami of Brachial Plexus

Back 33

Leave vertebral canal between anterior and posterior tubercles of cervicle vertebrae. In triangle, located between anterior and middle scalene muscles.

Front 34

Structures Between Investing and Prevertebral layers of Deep Cervical Fascia

Back 34

-Spinal Accessory Nerve
-Inferior Belly of omohyoid muscle
-transverse cervical vessels
-cutaneous nerves to the skin

Front 35

Strutures between the Carpet and Floor

Back 35

-Dorsal Scapular Nerve
-Long Thoracic Nerve
-Phrenic Nerve
-Proximal Portion of the Brachial Plexus
-3rd part of Subclavian Artery

Front 36

Spinal Accessory Nerve

Back 36

(CN 11) Lies just underneath investing layer of deep cervical fascia over the prevertebral layer of deep cervical fascia.
Innervates the Traps and SCM muscles.
Is all motor and no sensory; thats why muscles also need spinal nerve innervation as well for proprioception.

Front 37

Dorsal Scapular Nerve

Back 37

(C5) Nerve to rhomboids. Pass through middle scalene.

Front 38

Long Thoracic Nerve

Back 38

(C5, 6, 7) Nerve to serratus anterior. Passes through middle scalene.

Front 39

Phenic Nerve

Back 39

(C3,4,5) Nerve to diaphragm.

Front 40

Omohyoid Muscle (location, origin, insertion, innervation)

Back 40

One of infrahyoid muscles.
Inferior belly found in posterior triangle, intermediate tendon is undercover of SCM muscle, superior belly is in anterior triangle.
Origin - Upper border of scapula
Insertion - Lower border of hyoid bone
Innervation - ansa cervicalis

Front 41

Structures found between anterior and middle scalene

Back 41

Subclavian artery and ventral primary rami forming brachial plexus

Front 42

Structures superficial to anterior scalene

Back 42

-Prevertebral fascia
-subclavian vein
-phrenic nerve
-transverse cervical artery
-suprascapular artery
-omohyoid muscle

Front 43

structures above first rib (from anterior to posterior)

Back 43

Subclavian vein, anterior scalene, subclavian artery, lower part of brachial plexus, middle scalene.

Front 44

Nerves of Brachial Plexus

Back 44

C5-T1

Front 45

Sternoclavicular Joint

Back 45

Gliding Joint between medial clavicle and manubrium. Articular disk divides joint cavity into 2 separate spaces. Is a synovial joint.

Front 46

Ligaments of sternoclavicular articulation

Back 46

-articular capsule
-anterior and posterior sternoclavicular ligament
-interclavicular ligament
-costoclavicular ligament

Front 47

Subclavian Artery

Back 47

Branch off the Aortic Arch. Arches over lung and pleura. Passes between scalenus anterior and medius muscles and ends at lateral border of first rib. Changes name to axillary artery.

Front 48

Branches of Subclavian Artery (Situation 1)

Back 48

Section Medial to Anterior Scalene - Internal thoracic, Vertebral Artery, and thyrocervical trunk.
Trunks branches are inferior thyroid artery, transverse cervical artery, suprascapular artery.
Section behind anterior scalene - Costalcervical trunk.
Section Lateral to anterior scalene - no branches.

Front 49

Branches of Subclavian Artery (Situation 2)

Back 49

Section Medial to Anterior Scalene - Internal thoracic, Vertebral Artery, and thyrocervical trunk.
Trunks branches are inferior thyroid artery, transverse cervical artery, suprascapular artery.
Section behind anterior scalene - Costalcervical trunk.
Section lateral to anterior scalene - dorsal scapular artery. This takes the place of the deep branch of the transverse cervical. Deep branch is now called superficial cervical artery.

Front 50

Internal Thoracic Artery

Back 50

Arises from 1st section of subclavian (antero inferior). Descends posterior to sternal end of clavicle to enter thorax.

Front 51

Vertebral Artery

Back 51

Arises from 1st section of subclavian artery (postero superior) Enters trnasverse foramen of CV 6. Enters suboccipital triangle to supply brain and brainstem.

Front 52

Thyrocervical Trunk

Back 52

Arises from 1st section of subclavian artery (superior). Has 3 branches: inferior thyroid artery, ascending cervical artery, and inferior laryngeal artery.

Front 53

Inferior Thyroid Artery

Back 53

Branch off Thyrocervical Trunk. Ascends superiorly along medial border of scalene anterior, turns medially and branches at level CV 6 to ascending cervical artery and inferior laryngeal artery.

Front 54

Ascending Cervical Artery

Back 54

Branch off inferior thyroid artery. Parallels phrenic nerve on anterior surface of anterior scalene.

Front 55

Inferior Laryngeal

Back 55

Accompanies the recurrent laryngeal nerve.

Front 56

Transverse Cervical Artery

Back 56

Branch off thyrocervical trunk. Passes behind SCM muscle and infront of anterior scalene muscle. Turns posteriorly crossing triangle of neck. Divides into superficial and deep branches.

Front 57

Superficial Branch of Transverse Cervical

Back 57

Branch off transverse cervical artery. Accompanies accessory nerve on deep surface of trap.

Front 58

Deep Branch of Transverse Cervical

Back 58

Acompanies dorsal scapular nerve on deep surface of levator scapulae and rhomboids. Is the dorsal scapular artery if there is no branch from third section of subclavian. If there is a branch, is known as superficial cervical artery.

Front 59

Suprascapular Artery

Back 59

Branch off the thyrocervical trunk. Passes behind SCM and infront of anterior scalene. Travels behind clavicle to reach scapular notch where it crosses above transverse scapular ligament.

Front 60

Costocervical Trunk

Back 60

Arises from second section of subclavian artery (posterior). Quickly divides into Deep cervical artery and Highest intercostal artery.

Front 61

Deep Cervical Artery

Back 61

Branch off Costocervical Trunk. Supplies deep muscles on back of neck.

Front 62

Highest Intercostal Artery

Back 62

Supplies first 2 intercostal spaces.

Front 63

Subclavian Vein

Back 63

Begins at lateral border of first rib. Passes in front in anterior scalene. Joins internal jugular vein behind medial end of clavicle forming the brachicephalic vein.

Front 64

Internal Jugular Vein

Back 64

Begins at jugular foramen at base of skull. Lies within carotid sheath deep to SCM muscle. Joins subclavian vein behind medial end of clavical to form brachiocephalic vein.

Front 65

Thoracic Duct and right lymphatic duct; location where they drain into circulation.

Back 65

Near junction of the subclavian vein and internal jugular vein.

Front 66

Anterior Jugular Vein

Back 66

Drains anterior triangle of neck. Descends inferiorly close to midline. joins jugular arch located above jugular arch of sternum.

Front 67

Jugular Arch

Back 67

Located above jugular notch of sternum. Empties into external jugular vein but also communicates with interior jugular vein.

Front 68

External Jugular Vein

Back 68

Located anterior to SCM muscle at start, ends posterior to it. Carries blood from area inferior to ear and area just superior to clavicle. At clavicle, it dives deep and drains into subclavian vein.