Lymphatic system of the head and neck Flashcards
what does the lymphatic system consist of?
- organs (bone marrow, spleen and thymus)-primary
- lymphatic vessels (e.g. thoracic duct)-afferents/efferent
- lymph nodes -
- mucosa-associated lymphoid tissue (MALT eg “tonsils”)
what are the functions of the lymphatic system?
- 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
what are the main cells of lymph?
macrophages and lymphocytes
what is the major lymphatic vessel in the body that drains 3/4 of the body of lymph?
thoracic duct
what drains the top right side of the body?
right lymphatic duct
what is lymph?
- Excess fluid left in the tissues is called tissue fluid
- Once this fluid is taken up by lymphatic vessels it is called lymph
what is caused by insufficient drainage of lymph?
elephantiasis
how is lymph produced?
blood flows through capillary beds in the anatomical structures of the head & neck
where is there no lymphatics in the head and neck?
brain
what happens at the lymph nodes?
- 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)
what first receives lymph from any given structure/area?
regional lymph nodes
what are the 2 groups of lymph nodes in the head and neck?
- the superficial ring
- the deep cervical nodes.
what drains the lymphatic drainage of superficial structures of head and neck ?
superficial ring of regional lymph nodes (drain scalp, face, superficial upper neck)
what are the nodes in the superficial ring of regional lymph nodes?
- occipital
- mastoid
- superficial cervical
- parotid
- buccal
- submental
- submandibular
what drains deep structures of the head and neck?
deep cervical nodes (final common pathway from head and neck)
what are the deep cervical nodes?
- deep cervical nodes ( found under the sternocleidomastoid)
- retro-pharyngeal
- submental
- submandibualr
what are the 5 sets of tonsils?
1) palatine (oropharynx)
2) palate associated lymphoid tissue
3) adenoid ( pathological pharyngeal tonsil in nasopharynx)
4) tubal (in nasopharynx
5) lingual (oropharynx
what is waldeyer’s ring of lymphoid tissue?
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)
why are the tonsils considered the first line of defence against exogenous aggressors?
first site of encounter with inhaled and ingested micro-organisms
what is the most essential tonsillar function?
The generation of B cells in the germinal centres of the tonsil
where does lymph from the palatine tonsil drain to?
one specific deep cervical lymph node - the jugulo-digastric node
where does the lower anterior teeth, their associated gingivae, oral mucosa, alveolar and basal bone drain their first lymph to?
submental group of regional nodes (bilaterally)
where does all the other teeth and their soft and hard supporting tissues drain first to?
submandibular nodes(unilaterally))
where does the submental nodes drain next?
to the submandibular nodes (unilaterally)
