Organisation of The Neck and The Posterior Triangle Flashcards
What are the boundaries of the neck?
Superior - base of skull and inferior border of mandible
Inferior - top of sternum, clavicle, acromion (anterior) and C7 (posterior)
What are the compartments of the neck?
Visceral
Vascular
Vertebral
Describe the visceral compartment
Contains parts of the respiratory system, digestive system and endocrine glands
Describe the vascular compartment
Contains blood vessels and nerves (CN X)
Describe the vertebral compartment
Contains cervical vertebrae, spinal cord, muscles and cervical nerves
What is fascia and what are its purposes?
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
Describe superficial fascia
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)
Describe the investing layer of fascia
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
What are the superior attachments of the investing layer of fascia?
Superior nuchal line of the occipital bone
Mastoid processes of the temporal bone
Zygomatic arches
Inferior border of the mandible
What are the inferior attachments of the investing layer of fascia?
Spine of scapula
Acromion
Clavicle
Manubrium
What are the anterior and posterior attachments of the investing layer of fascia?
Anterior - hyoid bone
Posterior - ligamentum nuchae, periosteum of C7 spinous process
Describe the pretracheal layer of deep fascia
Visceral part - trachea, oesophagus and thyroid gland
Muscular part - infrahyoid muscles - separates them from trachea and thyroid
Pierced by thyroid vessels
Describe the prevertebral layer of deep fascia
Surrounds the vertebral column and pre- and post-vertebral muscles
Pierced by cutaneous branches of the cervical plexus
What is the carotid sheath?
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
What are the borders of the posterior triangle?
Anterior - posterior border of SCM
Inferior - middle third of clavicle
Posterior - anterior border of trapezius
Apex - superior nuchal line of occipital bone
What is found in the SCM region of the neck?
SCM
Great auricular nerve
Transverse cervical nerve
External jugular vein
What is found in the posterior cervical region of the neck?
Trapezius
Cutaneous branches of posterior rami of cervical spinal nerves
What can the posterior triangle be divided into and how?
Occipital triangle
Omoclavicular/subclavian triangle
Divided by inferior belly of omohyoid
Name the origins of the SCM
Sternal head - manubrium
Clavicular head - superior surface of medial third of clavicle
What is the insertion of the SCM?
Lateral surface of mastoid process and lateral half of superior nuchal line
What is the innervation of the SCM?
Spinal accessory nerve - CN XI
What are the actions of the SCM?
Draws the head forward - bilaterally, both muscles acting
Tilts head towards ipsilateral shoulder while turning face contralaterally - unilaterally
What are the origins of the trapezius?
Superior nuchal line
External occipital protuberance
Ligamentum nuchae
Spinous processes (C7-T12)
What are the insertions of the trapezius?
Lateral third of clavicle
Acromion
Spine of scapula
What is the innervation of the trapezius?
Spinal accessory nerve (CN XI)
What are the actions of the trapezius?
Assists in rotating scapula during abduction of humerus
Upper fibres elevate, middle adduct and lower depress scapula
What are the muscular branches of the cervical plexus?
Phrenic nerve - C3,4 and 5
Ansa cervicalis - C1,2 and 3
What are the cutaneous branches of the cervical plexus?
C2 - lesser occipital nerves
C2 and 3 - great auricular and transverse cervical nerves
C3 and 4 - supraclavicular nerves
What is the ansa cervicalis and what does it innervates?
Anterior rami of C1 - C3
Innervates infrahyoid muscles except the thyrohyoid
What vasculature is found in the posterior triangle?
External jugular vein which drains into the subclavian vein
Anterior jugular vein which drains into the external jugular vein
