Lymphatic system of the head and neck

Question 1

what does the lymphatic system consist of?

Answer 1

• organs (bone marrow, spleen and thymus)-primary
• lymphatic vessels (e.g. thoracic duct)-afferents/efferent
• lymph nodes -
• mucosa-associated lymphoid tissue (MALT eg “tonsils”)

Question 2

what are the functions of the lymphatic system?

Answer 2

• removes excess fluid (interstitial/tissue fluid) from the tissues of the body and returns it (as lymph) to the venous system
• carries fats from the GI tract to the venous system
• produces immune cells (lymphocytes, plasma cells & monocytes) in the defence against infection and cancer

Question 3

what are the main cells of lymph?

Answer 3

macrophages and lymphocytes

Question 4

what is the major lymphatic vessel in the body that drains 3/4 of the body of lymph?

Answer 4

thoracic duct

Question 5

what drains the top right side of the body?

Answer 5

right lymphatic duct

Question 6

what is lymph?

Answer 6

• Excess fluid left in the tissues is called tissue fluid

- Once this fluid is taken up by lymphatic vessels it is called lymph

Question 7

what is caused by insufficient drainage of lymph?

Answer 7

elephantiasis

Question 8

how is lymph produced?

Answer 8

blood flows through capillary beds in the anatomical structures of the head & neck

Question 9

where is there no lymphatics in the head and neck?

Answer 9

brain

Question 10

what happens at the lymph nodes?

Answer 10

• All the lymph is filtered as it passes through the lymph nodes
• Lymph is screened for infectious agents and cancer cells by the lymphocytes and macrophages in the lymph nodes
• If the lymph node attempts to fight against an infection in the lymph it produces germinal centres, enlarges and becomes painful due to its capsule stretching
• If cancer cells become stuck in a lymph node and escape the notice of the immune surveillance system a secondary tumour may grow in the node (metastasis)

Question 11

what first receives lymph from any given structure/area?

Answer 11

regional lymph nodes

Question 12

what are the 2 groups of lymph nodes in the head and neck?

Answer 12

• the superficial ring

- the deep cervical nodes.

Question 13

what drains the lymphatic drainage of superficial structures of head and neck ?

Answer 13

superficial ring of regional lymph nodes (drain scalp, face, superficial upper neck)

Question 14

what are the nodes in the superficial ring of regional lymph nodes?

Answer 14

• occipital
• mastoid
• superficial cervical
• parotid
• buccal
• submental
• submandibular

Question 15

what drains deep structures of the head and neck?

Answer 15

deep cervical nodes (final common pathway from head and neck)

Question 16

what are the deep cervical nodes?

Answer 16

• deep cervical nodes ( found under the sternocleidomastoid)
• retro-pharyngeal
• submental
• submandibualr

Question 17

what are the 5 sets of tonsils?

Answer 17

1) palatine (oropharynx)
2) palate associated lymphoid tissue
3) adenoid ( pathological pharyngeal tonsil in nasopharynx)
4) tubal (in nasopharynx
5) lingual (oropharynx

Question 18

what is waldeyer’s ring of lymphoid tissue?

Answer 18

the naso- and oropharynx, with some of its tonsillar tissue located above and some below the soft palate (and to the back of the oral cavity)

Question 19

why are the tonsils considered the first line of defence against exogenous aggressors?

Answer 19

first site of encounter with inhaled and ingested micro-organisms

Question 20

what is the most essential tonsillar function?

Answer 20

The generation of B cells in the germinal centres of the tonsil

Question 21

where does lymph from the palatine tonsil drain to?

Answer 21

one specific deep cervical lymph node - the jugulo-digastric node

Question 22

where does the lower anterior teeth, their associated gingivae, oral mucosa, alveolar and basal bone drain their first lymph to?

Answer 22

submental group of regional nodes (bilaterally)

Question 23

where does all the other teeth and their soft and hard supporting tissues drain first to?

Answer 23

submandibular nodes(unilaterally))

Question 24

where does the submental nodes drain next?

Answer 24

to the submandibular nodes (unilaterally)

Question 25

what are signs of dental abscesses?

Answer 25

patient will probably have enlarged, painful submental & submandibular lymph nodes

Question 26

where does the anterior 2/3rds of the tongue drain?

Answer 26

• MIDDLE- drains bilaterally to inferior deep cervical nodes
• SIDES- drain unilaterally to submandibular nodes
• TIP-drains bilaterally to submental nodes

Question 27

where does the posterior 1/3 rd of the tongue drain to?

Answer 27

bilaterally to superior deep cervical nodes

Question 28

what are the characteristics of lymph nodes in illness from infection?

Answer 28

• swollen
• painful
• soft
• smooth
• not fixed (stuck to) adjacent structures
• improve rapidly with antibiotics

Question 29

what are the characteristics of lymph nodes in illness from cancer?

Answer 29

• swollen
• not painful
• hard
• irregular
• fixed
• do not improve