Lymph Lecture COPY Flashcards
What are the functions of the lymphatic system?
Tissue drainage
Return of plasma and plasma proteins to circulatory system
Absorbed fat transport from gut
Immunity - great opportunity for antigen presentation
What are the constituents of the lymphatic system?
Lymphatic vessels - Differ from blood vessels in that they absorb proteins and other large molecules from tissue fluid
Lymphatic tissues – no basement membrane
Thymus, spleen, tonsils, nodules, bone marrow too
How does lymphatic system stop oedema?
Collects plasma proteins from extracellular space, these proteins are osmotically active
Lymph is fluid and plasma proteins only, but how does it collect lymphocytes?
As the lymph flows through the lymphatic capillaries and channels.
When is fat added to the lymph?
Small intestine?
What does lymph flow rely on?
Muscle contraction, gravity and pressure changes.
What do the valves of the lymph cause?
Unidirectional travel
What does the protein accumulation during an infection cause?
Fluid flow into extracellular spaces, this drives increased lymph flow and therefore immune response in nodes, as more antigens are presented and phagocytosis occurs.
What type of lymphoid organ are lymph nodes?
Secondary lymphoid tissue
Where are groups isolated or grouped?
At the bases of major arterial trunks
Does a lymph node have a blood supply?
Yes
Lymph flows slowly over lymph node (germinal centre - white cells, they contain B cell and T cell zone) because?
Allows antigenic presentation to occur
What is the name given to the secondary lymphoid follicles?
Germinal Centres
Give an example of Inert particles that will be filtered out in lymph nodes?
Carbon particles in a hilar lymph node (lung) (carbon containing = anthracotic)
Tattoo pigment in an axillary lymph node
What are the different drainage routes?
Limbs, cavities
Lymphatic vessels are absent from the eyeball, CNS, inner ear, epidermis, cartilage and bone
What is the drainage route for superficial area on the limbs?
Follow superficial veins
What is the drainage route for deep areas of the limbs?
Follow deep arteries and veins
E.g Muscle
What is the drainage route for body cavities?
follow deep arteries
What is the purpose of the saphenous opening?
Allows superficial drainage to pass through the deep fascia of thigh into the deep tissue drainage
Where are 50% of nodes?
In the abdomen and pelvis, associated with the gut
What are pre-aortic nodes?
On the front
Give examples of lymph node pathology
Primary tumours - lymphoma
Secondary tumours
Infections such as tuberculosis and glandular fever (mononucleosis)
Inflammatory hyperplasia
Initially drainage from the imbs, head and neck and trunk is Symmetrical?Unsymmetrical?
Symmetrical
Where does all lymph congregate?
2 Large lymph ducts
These empty into the venous system at the Jugular/ Subclavian junction
What is Lymph returning from the small intestine laden with?
Absorbed fats,
Eventually drains to the SVC (superior vena cava) and to the liver for absorption
What are the primary Lymphoid tissues?
Thymus and Bone marrow
What are the other lymphoid tissue?
Spleen (2o) Lymph nodes (2o) Peyer’s patches (2o) Tonsils Lymphocytes
What is the largest lymphatic organ?
Spleen
How is the contents of the spleen discharged?
Muscle action
What can be found in the white pulp?
B cells - germinal centres and T cells (PALS)
Where is there no lymph drainage?
No lymph drainage from skin, cartilage, bone or central nervous system, or from the majority of the spleen and liver.
