Anatomy & Physiology of the Neck

Question 1

What are the boundaries and contents of the anterior and posterior triangles of the neck?

Answer 1

Anterior triangle (CCA, IJV, Vagus & Hypoglossal):

• Midline
• Anterior border of SCM
• Inferior border of mandible
• Medial portion of clavicle

Posterior triangle (EJV, Subclavian Vein, Accessory Nerve):

• Posterior border of SCM
• Anterior border of Trapezius
• Middle 1/3 of clavicle

Question 2

What is the anatomy of the Thyroid and Parathyroid glands?

Answer 2

Thyroid:

• 2 lobes seperated by an isthmus
• Covers C5-T1
• Lies behind sternothyroid and sternohyoid muscles
• Supplied by superior thyroid artery

Parathyroid:

• Situated on the posterior surface of the thyroid lobes
• Supplied by inferior thyroid artery

Question 3

What is the clinical significance of neck anatomy, including neurovascular structures and lymph nodes?

Answer 3

Neurovascular structures:

The neck area contains many important structures that lie superficially and can therefore be easily damaged but also easily accessed:

• Central line placed in IJV

The neck also contains an important site where lymph fluid drains major abdominal organs:

• Virchows node receives lymph drainage from the abdominal cavity and an enlargement of virchows node is a sign of gastric cancer

Question 4

What is the pattern of lymph drainage around the head and neck?

Answer 4

Occipital Nodes - Drain the scalp

Parotid nodes - Face, scalp and parotid gland

Deep cervical nodes - final drainage pathway to the thoracic duct

Submandibular nodes - Tongue, nose, paranasal air sinuses, submandibular gland, oral cavity

Submental nodes - Lips, floor of mouth