Cervical fascia and lymphatics of head and neck

Question 1

Pathway of lymph

Answer 1

-Lymph-> lymphatic capillaries->afferent vessels-> lymph node-> efferent vessels-> trunk-> right lymphatic or thoracic duct

Question 2

5 branches of ECA

Answer 2

• From inferior->superior
• Superior thyroid artery
• Facial artery
• Occipital artery (only one branching posterior)
• 2 terminal branches: maxillary and superficial temporal
• ICA first branch is opthalmic, and this branch anastomoses w/ the occipital and superficial temporal (branches of ECA) at the scalp
• Branches of opthalmic also anastamose w/ facial artery, sphenopalatine artery, and greater palatine artery (all from ECA)

Question 3

Infrahyoid muscles

Answer 3

• All innervated by ansa cervicalis (C1-3) except cricothyroid (innervated by external branch of superior laryngeal nerve)
• All suprahyoid muscle innervated by CNs except geniohyoid (innervated by ansa cervicalis C1)

Question 4

Superficial lymph nodes of neck and head

Answer 4

• Pericervical collar of lymph nodes are found at the junction of the head and neck
• These superficial lymph nodes drain the head
• Superficial lymph nodes that drain the neck (superficial cervical nodes) are found along the course of the external and internal jugular veins
• These drain lymph from superficial tissues of the head and neck
• From pericervical collar nodes, efferent lymph vessels can drain into deep and/or superficial cervical nodes

Question 5

Deep lymph nodes of the neck

Answer 5

• Deep cervical lymph nodes are found in connective tissue of the carotid sheath, closely associated w/ internal jugular vein
• Receive lymph drainage from both superficial and other deep nodes (drain most of the head and neck)
• Most important is jugulodiagastric: large node on the IJV inferior to the posterior diagastric muscle
• Another important one is jugulo-omohyoid node: lying on the IJV just superior to omohyoid tendon
• Lymph leaving these nodes forms the jugular trunk which drains to the right lymphatic duct on right side and thoracic duct on left side

Question 6

Cancer and lymphatics

Answer 6

-Cancer of lymph nodes (particularly tongue) may metastasize unilaterally to other superficial/deep nodes on the same side or cross midline and metastasize bilaterally

Question 7

3 compartments of the neck

Answer 7

• Visceral: anterior part containing GI, respiratory, and endocrine structures
• Skeletal: cervical spine and associated muscles found posteriorly
• Carotid sheath: found laterally btwn the two structures contains the jugulodiagastric node, ansa cervicalis (in the sheath), carotid artery, IJV, and CN X

Question 8

Deep cervical fascia

Answer 8

• Each compartment is enclosed by a layer of fascia
• Investing layer: surrounds all internal structures (most superficial layer) including trapezius and SCM
• Prevertebral fascia: around spinal cord and deep neck muscles, contains the cervical sympathetic trunk
• Pretracheal fascia: contains viscera like trachea, esophagus, and thyroid gland
• Carotid sheath formed of contributions from adjacent fascia layers
• Retropharyngeal space: empty space btwn the prevertebral and pretracheal fascia

Question 9

Clinical importance of the retropharyngeal space

Answer 9

• Infections originating adjacent to the pharynx can potentially spread via the retropharyngeal space
• If this occurs, the infection can reach the superior or posterior mediastinum