Lymphatics

Question 1

Which three things form the anterior triangle of the neck?

Answer 1

Midline of neck

Inferior border of the mandible

Anterior border of the sternocleidomastoid

Question 2

What three things form the posterior triangle of the neck?

Answer 2

Posterior border of the SCM

Anterior border of the trapezius muscle

Middle third of the clavicle

• contains the supraclavicular (Virchow’s) nodes

Question 3

Where are the posterior cervical lymph nodes?

Answer 3

Between the posterior border of the scm and the and the anterior border of the trapezius muscle.

From mastoid bone down to clavicle.

Drains skin on back of head

Question 4

What do the submandibular nodes drain?

Answer 4

The structures of the floor of the mouth.

Question 5

What do the submental nodes drain?

Answer 5

The mandible teeth and intra-oral cavity

Question 6

What do the supraclavicular nodes drain?

Answer 6

The abdomen

Part of the thoracic cavity

Question 7

What is the function of lymph nodes?

Answer 7

Primarily act as filters; preventing spread of infection and cancers.

Question 8

In which triangle of the neck does most important lymphadenopathy occur?

Answer 8

Neither the anterior or posterior triangle, but between them, under the SCM is where the majority of lymphadenopathy occurs.

Question 9

What are the boundaries of the submandibular triangle?

Answer 9

Posterior belly of the digastric muscle

Anterior belly of the digastric muscle

Mandible

• This forms neck level 1 in the ENT classification of the neck.

Question 10

What are the boundaries of neck level 2 in the division of the neck?

Answer 10

This is the most superior area behind the SCM.

It is from the mastoid to the top of the hyoid bone.

Question 11

What are the boundaries of neck level 3 in the division of the neck?

Answer 11

This is the middle area behind the SCM.

It is from the hyoid bone to the top of the cricoid cartilage.

Question 12

What are the boundaries of neck level 4 in the division of the neck?

Answer 12

This is the most inferior area behind the SCM.

It is from the cricoid cartilage down to the clavicle.

Question 13

What are the boundaries of neck level 5 in the division of the neck?

Answer 13

Neck level 5 is the posterior triangle of the neck; trapezius, SCM and clavicle medial third

Question 14

What are the boundaries of neck level 6?

Answer 14

Below neck level 1.

From the hyoid bone down to the stern all notch, bordered by the neck midline and the anterior SCM border.

Question 15

Which vessels supply and drain a lymph node?

Answer 15

Multiple efferent lymphatic vessels

One afferant lymphatic vessel

Vein

Artery

Question 16

What shape should a lymph node be?

Answer 16

Oval

“Rugby balls are good, footballs are bad”

Question 17

How does lymph flow through a lymph node?

Answer 17

Note: valves in the lymphatic system prevent backflow

Fast flow route:
1. Afferant lymph vessels and one-way valve

2. Subcapsular sinus
3. Flows alongside trabeculae (dividing extensions of the capsule)
   - THIS IS ALONGSIDE WHERE THE CORTICAL FOLLICLES (T cells) SURROUND THE GERMINAL CENTRES (B-Cells)-
4. Cortical sinus
5. Medullary sinus (Macrophages, T cells and plasma cells in medulla)
6. Efferent lymphatic vessel

Slow flow route:

• once it enters the node, it also has a slow route that it can take: through the reticular fibres which house the lymphocytes (the bulk of the node)
• the lymphocytes hang on the nets of fibres and grab things out of the lymph as it flows past, like pirates in the rigging

Question 18

Where are lymphocytes present in the body?

Answer 18

Lymph nodes

Bone marrow

Liver

Spleen

Question 19

Where do the thoracic duct and right lymphatic duct drain to?

Answer 19

The jugular vein

Question 20

Which type of cell differentiation cluster activates Th cells?

Answer 20

CD4 = Th cells, which activate B cells

CD8 = Cytotoxic T cells