A29 - Lymphatics Flashcards
what makes up the lymphatic system?
- bone marow, spleen, thymus
- lymphatic vessels
- lymph nodes
- MALT
what does MALT stand for?
mucosa- associated lymphoid tissue
what is the fucntion 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
- carry fats from the GI tract to the venous system
- produces immune cells in the defence against infection and cancer
what is the major lymphatic vessel in the body that returns lymph to large veins in the neck?
thoracic duct
what is tissue fluid?
excess fluid left in the tissue
when is tissue fluid called lymph?
when the fluid is taken up by lymphatic vessels
what causes elephatistis?
insufficient drainage of lymph
where is lymph not produced?
in the brain
what do lymph nodes do?
- filter lymph
- screened it for infectious agents and cancer cells by the lymphocytes and macrophages
how do lymph nodes attempt to fight against infection?
produces germinal centres, enlarges and become painful due to its capsule stretching
what are regional lymph nodes?
the group of nosed which first receive lymph from any given structure/area
what is the drainage of the superficial structures of the head and neck?
superficial ring of regional lymph nodes
- occipital nodes
- mastoid nodes
- superficial cervical nodes
- parotid nodes
- buccal nodes
- submental nodes
- submandibular nodes
what is the drainage of the deep structures of the head and neck?
- deep cervical nodes
What is the name for the ring of lymphoid tissue which circumscribes the naso- and oropharynx?
Waldeyer’s defensive ring of lymphoid tissue
What is considered the first line of defence against exogenous aggressors in the mouth?
tonsils