Lymphatics Flashcards
What are the 3 main the functions of the lymphatic system?
1 - removes excess fluid (interstitial/tissue fluid) from the tissues of the body, “cleans” it and returns it (as lymph) to the venous system.
2- carries fat from the GI tract to the venous system
3- produces immune cells (lymphocytes, plasma cells and monocytes) in the defence against infection and cancer
What is the useful analogy for te lymphatic system?
The “Dripping Tap” analogy, with the hot as the arteriole, the cold as the venule and the tap as the lymphatic vessels, dripping lymph into the sink to be drained and cleaned.
What is lymph?
1 - Lymph: Watery solution which flows through lymphatic system.
Explain plasma to lymph
Starts out as blood plasma which has been forced out of capillaries in the capillary beds for exchange of nutrients and gases between blood and tissues. Capillaries reabsorb some fluid. BUT remaining fluid must be “soaked up” by lymphatic system to return it to where it needs to go, EXPECTING it along the way.
Only referred to as lymph once it is in the lymphatic vessels.
What are the main functional parts of the lymphatic system and what is the order of flow?
Lymphatic capillaries - wind around blood capillaries to absorb excess fluid
Lymphatic vessels - carry lymph
Lymphnodes - checkpoints that monitor and cleanse lymph as it is filtered through
Lymphatic trunk - collection of vessels and nodes
Lymphatic ducts - right and thoracic, site where lymph is drained back into circulatory system at point of least pressure, into veins.
Lymphatic organs and tissues = bone marrow (B-lymphocytes), thymus (T-lymphocytes), spleen, tonsils
Give a description of the right lymphatic duct’s size, location and drainage.
Located: base of the right side of the neck, goes along the medial border of the anterior scalene muscle. RIGHT VENOUS ANGLE
Size: 1.25 cm in length.
Drains: lymph to right arm, right side of head and neck and upper right quadrant of the torso.
Drains to: froms various combinations with the right subclavian vein and right internal jugular vein.
Give a description of the thoracic lymphatic duct’s size, location and drainage.
Location: root of neck to T12, LEFT VENOUS ANGLE Size: 38-45 cm in adults
Drains: lymph and fat (chyle) from left side of head and neck, left arm, lower limbs and rest of body that isnt drained by right lymphatic duct.
Drains into: the angle of left subclavian vein and left internal jugular vein
How much lymph is produced in the body daily and how much of this is produced from head and neck?
2-4 L of lymph, 400 mL from head and neck
Where is lymph screened for infectious agents and cancer cells and by what?
In the lymphnodes by lymphocytes and macrophages.
What does the lymph node do if it attempts to fight an infection in the lymph?
The lymph node will produce germinal centres, enlarge and become painful
Why is the production of germinal centres painful?
Due to the capsule of the lymphnode stretching.
What happens if a cancer cell becomes stuck in a lymph node and escapes the notice of the immune surveillance system?
A secondary tumour may grow in the node (metastasis)
What is the name of the group of nodes which FIRST recieve lymph from any given area/structure?
REGIONAL lymph nodes
What groups are the lymphnodes of the head and neck described as?
1- the superficial ring (and superficial cervical)
2- the deep ring
3- the deep cervical nodes
What does the horizontal superficial ring of lymph nodes surround?
The transition area of neck to head
What are the 6 main groups of lymphnodes in the horizontal superficial ring?
Submental Submandibular Parotid (s and d. aka preauricular) Mastoid (retroauricular) Occipital Buccal (also the Superficial Cervical)
