Posterior Triangle

Question 1

superior boundary of the neck

Answer 1

base of skull & inferior border of mandible

Question 2

inferior boundary of neck

Answer 2

top of sternum, clavicle, acromion (anterior) & C7 (posterior)

Question 3

what is fascia and why is it present

Answer 3

it is very thin connective tissue that surrounds compartments of the neck providing containment & protection for muscles / viscera & conduit for neurovascular structures

Question 4

superficial fascia

Answer 4

cervical subcutaneous connective tissue

Question 5

3 layers of deep fascia

Answer 5

pretracheal, investing and prevertebral

Question 6

what do the 3 layers of deep fascia form?

Answer 6

carotid sheath

Question 7

where is superficial fascia found

Answer 7

between the dermis and investing layer of deep fascia

Question 8

what is in superficial fascia

Answer 8

contains cutaneous nerves, vessels, superficial lymph nodes, fat and platysma (anterolaterally)

Question 9

investing layer purpose

Answer 9

encloses SCM & trapezius as well as parotid & submandibular glands

Question 10

what pierces through investing layer

Answer 10

external & anterior jugular veins and nerves including cervical plexus

Question 11

superior attachments of investing layer

Answer 11

• superior nuchal line of occipital bone
• mastoid processes of temporal bone
• zygomatic arches
• inferior border of mandible

Question 12

inferior attachments of investing layer

Answer 12

• spine of scapula
• acromion
• clavicle
• manubrium

Question 13

anterior attachments of investing layer

Answer 13

hyoid bone

Question 14

posterior attachments of investing layer

Answer 14

• ligamentum nuchae
• periosteum of C7 spinous process

Question 15

2 parts of pretracheal layer

Answer 15

1. visceral part - encloses trachea, oesophagus & thyroid gland
2. muscular part - encloses infrahyoid muscles / separates them from trachea & thyroid

Question 16

where does the pretracheal layer extend from and to

Answer 16

extends from hyoid bone to upper thoracic cavity

Question 17

what is pretracheal layer continuous with

Answer 17

posteriorly & superiorly continuous with buccopharyngeal fascia of pharynx

Question 18

what pierces the pretracheal layer

Answer 18

thyroid vessels

Question 19

what does pretracheal layer laterally fuse with?

Answer 19

alar fascia and carotid sheaths

Question 20

prevertebral layer is pierced by

Answer 20

cutaneous branches of cervical plexus

Question 21

superior, anterior and inferior connections of prevertebral layer

Answer 21

superiorly - fixed to cranial base
inferiorly - blends with endothoracic fascia peripherally
anteriorly - longitudinal ligament centrally (at T3/T4 level)

Question 22

lateral extension of prevertebral fascia is to where?

Answer 22

laterally extends over the first rib to surround axillary vessels & brachial plexus as axillary sheath

Question 23

how does carotid sheath connect to other fascia

Answer 23

anteriorly with investing + pretracheal
posteriorly with prevertebral layer

Question 24

major vasculature found within carotid sheath

Answer 24

1. common and interior carotid arteries
2. IJV
3. vagus nerve

Question 25

boundaries of anterior triangle

Answer 25

inferior border of mandible anterior border of SCM midline of the neck

Question 26

boundaries of posterior triangle

Answer 26

posterior border of SCM middle 1/3 of clavicle anterior border of trapezius

Question 27

4 main regions in neck

Answer 27

1. SCM region 2. posterior cervical region 3. lateral cervical region 4. anterior cervical region

Question 28

what is in the lateral cervical region

Answer 28

posterior triangle & omoclavicular triangle

Question 29

what is in anterior cervical region

Answer 29

anterior triangle + submandibular, submental, carotid & muscular triangles

Question 30

boundaries of posterior triangle

Answer 30

anterior - posterior border of SCM posterior - anterior border of trapezius inferior - middle 1/3 of clavicle apex - superior nuchal line of occipital bone

Question 31

SCM origin

Answer 31

sternal head attaches to manubrium clavicular head attaches to superior surface of medial 1/3 of sternum

Question 32

insertion of SCM

Answer 32

lateral surface of mastoid process & lateral half of superior nuchal line

Question 33

action of SCM

Answer 33

1. draws head forwards (bilaterally = both muscles acting) 2. tilts head towards ipsilateral shoulder while turning face contralaterally

Question 34

innervation of SCM

Answer 34

spinal accessory nerve CN XI (motor) C2 and C3 nerves (pain & proprioception)

Question 35

function of SCM in respiration

Answer 35

acts as an accessory muscle if head and neck are fixed; SCM elevates clavicles and manubrium

Question 36

to test SCM

Answer 36

head is turned to opposite side against resistance

Question 37

trapezius origin

Answer 37

- superior nuchal line - external occipital protuberance - ligamentum nuchae - spinous processes (C7 - T12)

Question 38

insertion of trapezius

Answer 38

lateral 1/3 of clavicle acromion spine of scapula

Question 39

innervation of trapezius

Answer 39

spinal accessory nerve CN XI

Question 40

action of trapezius

Answer 40

assists in rotating scapula during abduction of humerus; upper fibres elevate, middle adduct and lower depress scapula

Question 41

to test trapezius

Answer 41

shoulder shrugged against resistance & superior border can be seen / palpated

Question 42

cervical plexus

Answer 42

anterior rami of C1, C2-C4

Question 43

muscular branches of cervical plexus

Answer 43

phrenic nerve C3, C4, C5 ansa cervicalis C1, C2, C3

Question 44

cutaneous branches of cervical plexus

Answer 44

C2 - lesser occipital nerves C2, C3 - great auricular & transverse cervical nerves C3, C4 - supraclavicular nerves

Question 45

where are cutaneous branches

Answer 45

superficial to prevertebral layer of fascia

Question 46

where are muscular branches

Answer 46

deep to prevertebral layer of fascia

Question 47

where is ansa cervicalis

Answer 47

anterior rami of C1-C3

Question 48

function of ansa cervicalis

Answer 48

innervates infrahyoid muscles

Question 49

where does external jugular vein drain

Answer 49

drains into subclavian vein

Question 50

where does anterior jugular vein drain

Answer 50

drains into external jugular vein

Question 51

what crosses the SCM

Answer 51

EJV great auricular nerve transverse cervical nerve

Question 52

what crosses posterior triangle (superficial to prevertebral fascia)

Answer 52

spinal accessory nerve EJV lesser occipital nerve transverse cervical artery + vein supraclavicular nerves