Lymphatics Flashcards
What are the functions of the lymphatic system?
- tissue drainage
- return of plasma and plasma proteins
- absorbed fat transport from gut
- immunity
How do lymphatic vessels differ from blood vessels?
They absorb proteins and other large molecules from tissue fluids
Name 5 lymphatic tissues?
- thymus
- spleen
- tonsils
- nodules
- bone marrow
What role does the lymphatic system play in tissue drainage?
It drains escaped cell-free plasma from the extracellular spaces back to the venous system
What is the composition of lymph?
- Lymph is fluid and plasma proteins.
- It gains lymphocytes as it flows through the lymphatic capillaries.
- Fats ate added in the small intestine.
What does lymphatic flow rely on?
- muscle contraction
- pressure changes
- gravity
Why is lymphatic flow unidirectional?
Valves
Why does fluid flow into extracellular spaces increase during infection?
Due to protein accumulation (osmosis) that drives increased lymph flow and therefore immune response in nodes, as more antigens are presented and phagocytosis occurs.
Where are the immunological functions of lymph located?
Where lymph nodes are periodically traversed by lymphatic vessels
Where do groups of lymph nodes occur?
at the bases of major arterial trunks
How much fluid is absorbed in the lymph nodes each day?
8L
How does efferent lymph differ from afferent lymph?
efferent lymph is filtered and contains more antibodies
What are germinal centres?
the secondary lymphoid follicles
What will be filtered out by the lymph nodes?
inert particles
What does anthracotic mean?
carbon containing
What are the lymph drainage roots?
- limbs either superficial follow superficial veins or deep follow deep arteries and veins
- cavities follow deep arteries
Where are lymphatic vessels absent from?
- eyeball
- CNS
- inner ear
- epidermis
- cartilage
- bone
Where are superficial inguinal nodes located?
In and around the femoral triangle at the base of the lower limb
Where is the saphenous opening and what does it demarcate?
It is in the fascia lata (deep fascia of the thigh)
-Demarcates between superficial and deep routes of lymphatic drainage
Where are 50% of nodes located?
abdomen and pelvis
What are pre-aortic nodes associated with?
The midline, unpaired aortic branches supplying the GIT, drainage via named arterial noes
What are para-aortic (lateral/lumbar) nodes associated with?
Paired, lateral branches to body wall and paired organs
How can lymph nodes develop into disease?
-primary tumours (lymphomas) such as Hodgkin’s
-secondary tumours as a result of metastasis from other sites?
-infection such as TB and glandular fever (mononucleosis)
inflammatory hyperplase
Describe lymph drainage.
- Initially symmetrical from limbs, head, neck and trunk
- ultimately all lymph congregates into 2 large lymph ducts
- these empty into the venous system at the jugular/subclavian junction
How is lymph involved in fat transport?
Lymph returning from the small intestine is laden with absorbed fats, which will also drain to the SVC and eventually to the liver for absorption
Where are lymphocytes generated and matured?
- thymus and bone marrow
- spleen
- lymph nodes
- peyers patches
- tonsils
- lymphocytes
Where is the spleen located?
upper left quadrant of abdomen
What does the spleen contain?
large amounts of bl0ood, routinely discharged via smooth muscle action
What is white pulp?
The immune function where T (PALS) and B(germinal centres) cells are found
