Lymphatic System Flashcards
Which sites have no lymphatic drainage?
Eyeball
Inner ear
Cartilage
How much lymph is produced a day?
3 - 4 litres
What is the role of the lymphatic system normally?
Continuous removal of remaining tissue fluid from extracellular space back to blood circulation
Why can the lymphatic system be dangerous?
Route for spread of infection and malignancy
Describe the flow of lymph from tissue fluid back to blood
Tissue fluid > lymphatic capillary > afferent lymphatic vessels > lymph nodes > efferent lymphatic vessels > lymphatic trunks > lymphatic ducts
What do we call the lymphatic ducts on the left and right?
Left = thoracic duct Right = right lymphatic duct
How are lymph nodes designed to help their function?
Lots of vessels enter a lymph node
Only one vessel to exit
Back log - increased pressure to help
Has valves to prevent backflow
Describe passive constriction of lymphatic vessels
Pulsation of arteries
Muscle contraction
Describe intrinsic constriction of lymphatic vessels
As vessels stretch they have the ability to contract
Autonomic SM
Why does lymph drain into the venous system?
Lowest pressure of blood circulation
Easiest point in which to drain
Which part of the body does the right lymphatic duct drain?
RHS of body from head to diaphragm
Lymphatic ducts drain into which veins?
Subclavian veins
Is lymphoedema pitting or non-pitting?
Non-pitting
What is lymphoedema?
Abnormal collection of protein-rich fluid causing tissue swelling due to compromised lymphatic system
Give some causes of lymphoedema
Removal/enlargement of lymph nodes Infections Damage - eg. Via cancer treatments Lack of limb movements Congenital
What are the lymphoid organs?
Lymph nodes
Spleen
Thymus
Tonsils
Describe the defences present in lymph nodes
Physical filter - reticular CT
Phagocytic filter - macrophages (and are APCs)
Activation and proliferation of lymphocytes - this is why nodes swell
What is the difference between a node swelling due to infection and due to malignancy?
Infection = tender and mobile Malignancy = hard, matted, not tender, craggy
What are the 2 broad groups of lymph nodes?
Regional (superficial) draining specific areas
Terminal (deep) receiving drainage from a number of regional ones
Approximately how many lymph nodes are there in the human body?
800
Approximately how many lymph nodes are in the neck alone?
300
What are the sites of the superficial cervical lymph nodes?
Submental Submandibular Pre-auricular Post-auricular Occipital Superficial cervical Posterior cervical Anterior cervical
What is Waldeyer’s ring?
Annular collection of lymphatic tissue surrounding superior pharynx
Consists of pharyngeal, palatine and lingual tonsils
What are the names of the deep lymph nodes of the H and N?
Tonsillar/jugulo-digastric
Jugulo-omohyoid
Supraclavicular
The left supraclavicular node drains the ..
Abdomen and thorax
The right supraclavicular node drains the…
Midsection chest
Oesophagus
Lungs
What drains into the submandibular node?
Upper lip and teeth Lateral part of lower lip Most of face Anterior nasal cavity Middle of tongue Submandibular and sublingual glands
What drains into the submental node?
Lower lip and teeth
Anterior chin
Tip of tongue
Floor of mouth
What drains into the pre-auricular node?
Scalp
Anterior ear
Parotid gland
What drains into the post-auricular node?
Scalp
Posterior ear
Ear canal
Which node is the most frequently enlarged and where does it drain?
Jugulo-digastric
Palatine tonsils, oral cavity, posterior 1/3 tongue, pharynx and larynx
