What’s in the Anterior triangle?
• Strap muscles: 3 further Triangles
• Common carotid artery bifurcates within the triangle
into the external and internal carotid arteries.
• The internal jugular vein also can be found within this
area. It drains blood from the head and neck.
• Facial [VII], Glossopharyngeal [IX], vagus [X],
• Accessory [XI], and Hypoglossal [XII] nerves.
• Lymph nodes
• Facial artery and vein (Submandibular traingle)
• Thyroid and Parathyroids
Lovers Find Old
Others Prefer S
-Some angry lady figured out PMS
What’s in the posterior triangle?
• Omohyoid muscle- The inferior belly crosses the
• Scalene muscles
• Subclavian artery-between anterior and middle scalenes,
Crosses 1st rib=__________
• CVP lines: External jugular vein which empties
into Subclavian vein.
Nerves in Posterior triangle
• The accessory nerve (XI), descends down the neck. After
innervating the sternocleidomastoid muscle, it enters the
posterior triangle. Lies relatively superficially in the posterior
triangle, and is at danger of injury.
• The cervical plexus forms within the muscles of the floor of
the posterior triangle. A major branch of this plexus is the
phrenic nerve, which arises from the anterior divisions of
spinal nerves C3-C5. It descends down the neck, within the
prevertebral fascia, to innervate the diaphragm.
• The trunks of the brachial plexus also cross the floor of the
• Investing Layer
• Most superficial of the deep cervical fascial layers.
• Surrounds all the structures in the neck.
• When it meets the trapezius and sternocleidomastoid
muscles, it splits into two to completely invest the muscle.
• Pretracheal Layer
• It envelops the trachea, oesophagus, thyroid gland,
and the infrahyoid muscles, running from the hyoid
bone down to the superior thorax, where it fuses with
• This layer of fascia can be functionally split into two
-Visceral part – encloses the thyroid gland, trachea and
-Muscular part – encloses the infrahyoid muscles.
• Prevertebral Layer
• Surrounds the vertebral column and its associated
muscles (scalence, pre-vertebral, and deep muscles of
• In the inferior region of the neck, the fascia surrounds
the brachial plexus and subclavian artery, and here it is
known as the axillary sheath.
• Carotid sheaths
1. Common carotid artery (bifurcates within the carotid
sheath into the external and internal carotid arteries)
2. Internal jugular vein
3. Vagus nerve
• Cervical lymph nodes
• Column that descends from the base of the skull to the
thorax. This represents a pathway for the spread of
infection, and it clinically very important.
• Clinical Relevance: Spread of Infections
• A superficial skin abscess is prevented from spreading
further into the neck by the investing layer of fascia.
• 1. Erosion through the prevertebral fascia and drainage
into the retropharyngeal space can cause extension into
the thorax +/-affect pericardium.
• 2. Between the investing fascia and pretracheal fascia This can spread inferiorly into the chest, causing infection
anterior to the pericardium.
• Air filled extensions of the respiratory part of the nasal
• There are four paired sinuses, named according to the
bone they are located in; maxillary, frontal, sphenoid and
• Contribute to the humidifying of the inspired air. They also
reduce the weight of the skull.
• As they are outgrowths of the nasal cavity, they all drain
back into it.
• Frontal Sinuses: Drain into the nasal cavity via the frontonasal duct.
• Sphenoid Sinuses: Drain out onto the roof of the nasal cavity. This relations of this
sinus are of clinical importance – the pituitary gland can be surgically accessed via
passing through the nasal roof, into the sphenoid sinus and through the sphenoid bone.
• Ethmoidal Sinuses: Empty into nasal cavity at different places
• Maxillary Sinuses: The largest. Located laterally and slightly inferiorly to the nasal
cavities. It drains into the nasal cavity underneath the frontal sinus opening. This is a
potential pathway for spread of infection – fluid draining from the frontal sinus can enter
the maxillary sinus.
Clinical Relevance: Sinusitis
As the paranasal sinuses are continuous with the nasal cavity, an upper respiratory tract
infection can spread to the sinuses. Infection of the sinuses causes inflammation
(particularly pain and swelling) of the mucosa.
The maxillary nerve supplies both the maxillary sinus and maxillary teeth, and so
inflammation of that sinus can present with
Exam: What is this lump?
• History-Slow/Fast/Pain/Associated red flags
-Hoarseness of voice
-Other primary cancer of head and neck
-Position-gland, LN, BCC
• A goitre is a swelling of the neck or larynx resulting from
enlargement of the thyroid gland, associated with a
thyroid gland that is functioning properly or not.
• Thyroid function may be normal (nontoxic goiter),
overactive (toxic goiter), or underactive (hypothyroid).
• Why operate?
Lumps in the anterior triangle
• Salivary gland pathology (stone, tumour, infection)
• Branchial cyst
• Parotid gland swelling
• Carotid body tumour/ Carotid aneurysm
UNILATERAL vs BILATERAL:
Sialectasis - especially if related to eating
• High oestrogen contraceptive pills
Lumps in the posterior triangle
• Cervical rib
• Pharyngeal pouch
• Cystic hygroma (usually on the left)
Investigating a lump
• Decide on urgency (2WW)
• Blood tests:
• FNA/Biopsy –Clinic or Theatre
• Cervical/Chest Xrays
• CT or MRI
• External Jugular Vein Distention:
This is the result of elevated central venous pressure
In practice the EJV is not as reliable in determining CVP as
the internal jugular vein
• Failure obliteration of
second branchial cleft
• Anterior border of SCM
• Congenital multiloculated
lymphatic lesion that can
arise anywhere, but
classically found in the left
posterior triangle of the
• Benign but can be
• Associated with Turners ad
• A 55-year-old
with a 8-month
weight loss, and
• In the previous 3
months, he had
lost 10 kg
• Strong indication of abdominal cancer
• Lymphatic drainage of most of the body (from the thoracic duct)
enters the venous circulation via the left subclavian vein.
• The metastasis blocks the thoracic duct leading to regurgitation
into the surrounding
• Differential diagnosis: lymphoma, breast cancer, infection
• Enlarged right supraclavicular lymph node tends to drain
thoracic malignancies such as lung and oesphageal cancer
-Arrange bloods, CXR, Urgent Endoscopy +/-CT Scan for mets
• Neck triangles
• Lymph node distribution
• Blood supply
• Emergency airway management
• How to examine a thyroid and Parotid
• Common Skull/Face #
• Headache distribution