9: Posterior Neck

Question 1

platysma m.

Answer 1

• very superficial facial muscle - for frowning
• Platysma means plate-like or flat
• First muscle of facial expression that we’ve learned. Innervated by facial nerve VII.
• Originates in subcutaneous tissue - Covers over pec major
• Inserts into mandible and fascia of the cheek – tenses the fascia

Question 2

plastysma innervated by

Answer 2

CN VII - facial

Question 3

platysma origin

Answer 3

Origin - subcutaneous tissue over pectoralis major and deltoids

Question 4

platysma insertion

Answer 4

Insertion - mandible and fascia of cheek

Question 5

platysma action

Answer 5

Main action: draws corners of mouth inferiorly and widens it as in expressions of sadness and fright

platysma plays only a minor role in depressing the lip which is primarily performed by the depressor anguli oris and the depressor labii inferioris

Question 6

posterior cervical triangle boundaries

Answer 6

posteriorally = trapezius m.
anteriorally = SCM m.
inferiorally = clavicle

Question 7

what separates the posterior cervical triangle from the anterior cervical triangle?

Answer 7

sternocleidomastoid m.

Question 8

what is visible in the posterior cervical triangle from the skin? (superficial anatomy)

Answer 8

trapezius
external jugular vein
clavicular and sternal heads of SCM

Question 9

superficial veins of the posterior cervical triangle

Answer 9

posterior auricular drains into external jugular vein
retromandibular posterior division drains into external jugular vein
anterior division goes to the facial vein
external jugular drains to subclavian vein which drains to the SVC

Question 10

SCM actions

Answer 10

side flexion of the head to the same side

rotating the head to the opposite side

Question 11

posterior auricular v. drains into the

Answer 11

external jugular v.

Question 12

retromandibular posterior v. drains into the

Answer 12

external jugular v.

Question 13

retromandibular anterior v. drains into the

Answer 13

facial v.

Question 14

external jugular v. drains into the

Answer 14

subclavian v. which drains into the superior vena cava

Question 15

posterior triangle borders

Answer 15

Anterior - Sternocleidomastoid m.
Posterior - Trapezius m.
Inferior - Clavicle

Question 16

posterior cervical triangle subdivided into two triangles

Answer 16

Occipital - above the omohyoid

Supraclavicular - below the omohyoid

Question 17

muscle that bisects the posterior cervical triangle

Answer 17

inferior belly of omohyoid m.

Question 18

occipital triangle borders

Answer 18

Anterior: Sternocleidomastoid

Inferior: Inferior belly of the omohyoid

Posterior: Trapezius

Question 19

contents of occipital triangle

Answer 19

Cutaneous nerves of cervical plexus:

Lesser occipital nerve, from C2-C3
Great Auricular nerve, from C2-3
Transverse cervical nerve, from C2-3
Lateral, intermediate and medial supraclavicular nerves, from C3-4

Spinal accessory (CN XI) nerve to sternocleidomastoid and trapezius muscles

Floor:

Splenius capitis, levator scapulae muscles
“Scalene muscles” (middle/posterior) when trapezius and SCM are removed

Question 20

Cutaneous nerves of cervical plexus:

Answer 20

Lesser occipital nerve, from C2-C3
Great Auricular nerve, from C2-3
Transverse cervical nerve, from C2-3
Lateral, intermediate and medial supraclavicular nerves, from C3-4

Question 21

nerves from C2-C3

Answer 21

lesser occipital
greater auricular
transverse cervical

Question 22

nerves from C3-C4

Answer 22

lateral, intermediate, and medial supraclavicular nerves

Question 23

Spinal accessory (CN XI) nerve innervates

Answer 23

sternocleidomastoid and trapezius muscles (motor only)

Question 24

floor of occipital triangle

Answer 24

Splenius capitis, levator scapulae muscles

“Scalene muscles”

Question 25

cervical plexus formed by

Answer 25

union of adjacent ventral rami of the first 4 cervical nerves

Question 26

cutaneous branches of the cervical plexus

Answer 26

Cutaneous (sensory) branches arise around the middle of the posterior border of SCM ``` Lesser occipital Great auricular Transverse cervical Supraclavicular nn. (Lat, Med, Int.) ```

Question 27

most posterior cutaneous branch of cervical plexus

Answer 27

Lesser Occipital

Question 28

cutaneous n. anterior to the lesser occipital n.

Answer 28

great auricular n.

Question 29

wraps around anterior border of SCM

Answer 29

transverse cervical n.

Question 30

Great auricular nerve (GA) innervates

Answer 30

ascends vertically over the parotid gland where it divides and supplies the skin over the gland, the posterior aspect of the auricle

Question 31

Lesser Occipital nerve (LO): path and innervates

Answer 31

supplying the skin of the neck and scalp posterosuperior to the auricle (scalp above the ear)

Question 32

Transverse cervical nerve (TC): path and innervates

Answer 32

supplying the skin covering the anterior cervical region; passes from the posterior border of SCM; supplies sensory innervation to the skin in that area

Question 33

Supraclavicular nerves (SC): path and innervates

Answer 33

Emerge as a common trunk under the SCM and send small branches (Lateral LSC, Medial MSC, Intermediate ISC) to the skin of the neck and cross the clavicle to supply the skin over the shoulder

Question 34

cervical plexus nerve block

Answer 34

For surgical procedures in the neck region or upper limb, anesthetic is injected at several points along the posterior border of SCM, mainly at the Nerve point of the neck.

Question 35

spinal accessory path

Answer 35

Emerges from middle of posterior border of SCM, crosses occipital triangle and passes deep to the superior border of the trapezius to innervate it.

Question 36

occipital triangle muscles include

Answer 36

``` (in order from posterior to anterior) splenius capitus levator scapulae posterior scalene (2nd rib) middle scalene (1st rib) anterior scalene (1st rib) ``` borders: trapezius, SCM, omohyoid inferior belly

Question 37

which nerve courses over the anterior scalene m.?

Answer 37

phrenic n.

Question 38

location of the cervical plexus

Answer 38

deep to the SCM, except for the transverse cervical n. which travels on its surface

Question 39

cervical plexus formed by

Answer 39

union of adjacent ventral rami of the first 4 cervical nerves

Question 40

supraclavicular triangle borders

Answer 40

(the little triangle of the posterior triangle) Anterior: Sternocleidomastoid Superior: Inferior belly of the omohyoid Inferior: Clavicle

Question 41

contents of supraclavicular triangle

Answer 41

(the little triangle on the posterior neck) Phrenic nerve :C3,4,5 Brachial plexus (roots, trunks, and some branches) Subclavian artery Transverse cervical artery Dorsal scapular artery Suprascapular artery Subclavian vein

Question 42

course behind (posterior to) the anterior scalene m.

Answer 42

Subclavian artery + brachial plexus

Question 43

courses over (anterior to) the anterior scalene m.

Answer 43

Subclavian vein

Question 44

roots of brachial plexus

Answer 44

Ventral rami of spinal n. C5-T1

Question 45

trunks of brachial plexus

Answer 45

Ventral rami C5&C6=upper trunk Ventral rami C7=middle trunk Ventral rami C8&T1=lower trunk

Question 46

to stop upper limb bleeding

Answer 46

press subclavian a. against the ribs

Question 47

anterior surface of scalene muscle

Answer 47

``` Phrenic Transverse cervical Suprascapular a Subclavian v + more, will see later (vagus) ```

Question 48

dorsal scapular a. a continuation of

Answer 48

the transverse cervical a.

Question 49

branches of subclavian artery

Answer 49

``` Vertebral artery Thyrocervical trunk: Transverse cervical artery Suprascapular artery Ascending cervical artery Inferior thyroid artery ``` Costocervical trunk: 1. Deep cervical artery 2. Supreme intercostal artery

Question 50

floor of supraclavicular triangle

Answer 50

middle and posterior scalene muscles

Question 51

dorsal scapular n. branches from

Answer 51

ramus of C5

Question 52

suprascapular n. branches from

Answer 52

upper trunk

Question 53

long thoracic comes from

Answer 53

rami of C5-C7

Question 54

boundaries of the anterior part of the neck

Answer 54

Superior: Body of mandible, mastoid process of temporal bone Anterior: midline Inferior: Clavicle, manubrium of sternum Posterior: Trapezius m., anterior border