Organisation of The Neck and The Posterior Triangle

Question 1

What are the boundaries of the neck?

Answer 1

Superior - base of skull and inferior border of mandible
Inferior - top of sternum, clavicle, acromion (anterior) and C7 (posterior)

Question 2

What are the compartments of the neck?

Answer 2

Visceral
Vascular
Vertebral

Question 3

Describe the visceral compartment

Answer 3

Contains parts of the respiratory system, digestive system and endocrine glands

Question 4

Describe the vascular compartment

Answer 4

Contains blood vessels and nerves (CN X)

Question 5

Describe the vertebral compartment

Answer 5

Contains cervical vertebrae, spinal cord, muscles and cervical nerves

Question 6

What is fascia and what are its purposes?

Answer 6

Connective tissue that surrounds the compartments of the neck
Provides containment and protection for muscles, blood vessels and nerves
Provides slipperiness that allows structures to slide over each other

Question 7

Describe superficial fascia

Answer 7

Cervical subcutaneous connective tissue
Continuous with superficial fascia of thorax
Connects to mandible and facial muscles
Contains cutaneous nerves, vessels, superficial LNs and fat
Contains platysma (anterolaterally)

Question 8

Describe the investing layer of fascia

Answer 8

Surrounds the neck completely
Splits into superficial and deep layers to enclose the trapezius and SCM, and parotid and submandibular glands
Pierced by external and anterior jugular veins and nerves including the cervical plexus

Question 9

What are the superior attachments of the investing layer of fascia?

Answer 9

Superior nuchal line of the occipital bone
Mastoid processes of the temporal bone
Zygomatic arches
Inferior border of the mandible

Question 10

What are the inferior attachments of the investing layer of fascia?

Answer 10

Spine of scapula
Acromion
Clavicle
Manubrium

Question 11

What are the anterior and posterior attachments of the investing layer of fascia?

Answer 11

Anterior - hyoid bone
Posterior - ligamentum nuchae, periosteum of C7 spinous process

Question 12

Describe the pretracheal layer of deep fascia

Answer 12

Visceral part - trachea, oesophagus and thyroid gland
Muscular part - infrahyoid muscles - separates them from trachea and thyroid
Pierced by thyroid vessels

Question 13

Describe the prevertebral layer of deep fascia

Answer 13

Surrounds the vertebral column and pre- and post-vertebral muscles
Pierced by cutaneous branches of the cervical plexus

Question 14

What is the carotid sheath?

Answer 14

Layer of deep fascia that has boundaries with all 3 layers of deep cervical fascia
Surrounds common carotid artery, internal jugular vein and CN X
Also contains deep cervical lymph nodes and other nerves

Question 15

What are the borders of the posterior triangle?

Answer 15

Anterior - posterior border of SCM
Inferior - middle third of clavicle
Posterior - anterior border of trapezius
Apex - superior nuchal line of occipital bone

Question 16

What is found in the SCM region of the neck?

Answer 16

SCM
Great auricular nerve
Transverse cervical nerve
External jugular vein

Question 17

What is found in the posterior cervical region of the neck?

Answer 17

Trapezius
Cutaneous branches of posterior rami of cervical spinal nerves

Question 18

What can the posterior triangle be divided into and how?

Answer 18

Occipital triangle
Omoclavicular/subclavian triangle
Divided by inferior belly of omohyoid

Question 19

Name the origins of the SCM

Answer 19

Sternal head - manubrium
Clavicular head - superior surface of medial third of clavicle

Question 20

What is the insertion of the SCM?

Answer 20

Lateral surface of mastoid process and lateral half of superior nuchal line

Question 21

What is the innervation of the SCM?

Answer 21

Spinal accessory nerve - CN XI

Question 22

What are the actions of the SCM?

Answer 22

Draws the head forward - bilaterally, both muscles acting
Tilts head towards ipsilateral shoulder while turning face contralaterally - unilaterally

Question 23

What are the origins of the trapezius?

Answer 23

Superior nuchal line
External occipital protuberance
Ligamentum nuchae
Spinous processes (C7-T12)

Question 24

What are the insertions of the trapezius?

Answer 24

Lateral third of clavicle
Acromion
Spine of scapula

Question 25

What is the innervation of the trapezius?

Answer 25

Spinal accessory nerve (CN XI)

Question 26

What are the actions of the trapezius?

Answer 26

Assists in rotating scapula during abduction of humerus
Upper fibres elevate, middle adduct and lower depress scapula

Question 27

What are the muscular branches of the cervical plexus?

Answer 27

Phrenic nerve - C3,4 and 5
Ansa cervicalis - C1,2 and 3

Question 28

What are the cutaneous branches of the cervical plexus?

Answer 28

C2 - lesser occipital nerves
C2 and 3 - great auricular and transverse cervical nerves
C3 and 4 - supraclavicular nerves

Question 29

What is the ansa cervicalis and what does it innervates?

Answer 29

Anterior rami of C1 - C3
Innervates infrahyoid muscles except the thyrohyoid

Question 30

What vasculature is found in the posterior triangle?

Answer 30

External jugular vein which drains into the subclavian vein
Anterior jugular vein which drains into the external jugular vein