Lymph Nodes and Spleen Flashcards
Precursor lymphoid cells which want to become B cells undergo maturation where?
Bone marrow
Precursor lymphoid cells which want to become T cells undergo maturation where?
Thymus
What are the two central (primary) components of the lymphoid system?
Bone marrow and thymus
What are some peripheral (secondary) components of the lymphoid system?
Lymph nodes, spleen, tonsils
The lymphatics return lymph fluid into the circulation. What are the purposes of this?
Important in fluid homeostasis and prevention of oedema
What are some lymph node groups that can be palpated?
Cervical, axillary and inguinal
What are some groups of lymph nodes which can be viewed radiologically?
Mediastinal and para-aortic
Describe the movement of fluid within lymph vessels?
Passive movement of fluid, with valves ensuring unidirectional flow
What are the main cell types found in a lymph node?
Lymphocytes, macrophages and endothelial cells
What are the ways of classifying lymphadenopathy?
Localised, widespread or generalised / peripheral or central
What are the main causes for lymphadenopathy?
Local or systemic inflammation and malignancy
Generalised lymphadenopathy suggests what?
A systemic inflammatory process or widespread malignancy (mainly leukaemia/lymphoma)
What is the best blood test to do if a patient presents with generalised lymphadenopathy?
FBC
If there is a predominantly B cell immune response in a lymph node, what are some likely causes?
Autoimmune conditions, infections
If there is a predominantly T cell immune response in a lymph node, what are some likely causes?
Viral infections, drugs e.g. phenytoin
If there is a predominantly phagocytic immune response in a lymph node, what is a likely cause?
Draining a tumour site
Sarcoidosis typically presents with what? What is important to be aware of about sarcoid like reactions?
Predominantly hilar but also cervical lymphadenopathy / can mask an underlying malignancy
Where is the spleen located? Is it usually palpable?
In the left upper quadrant / no, not unless it is substantially enlarged
Describe the arterial supply to the spleen?
The splenic artery, which is a branch of the coeliac axis
Describe the venous drainage from the spleen?
Via the splenic vein, which combines with the superior mesenteric vein to form the portal vein
What is important to be aware about a diseased spleen?
It is more prone to rupture
What is the function of the red pulp of the spleen?
It acts as a filter for the blood - it eliminates unwanted material and facilitates immune responses to blood borne viruses
What is the function of the white pulp of the spleen?
Antigen presentation to immune reactive cells
What are some clinical features of splenic enlargement?
Dragging sensation in the LUQ, discomfort with eating, pain if infarction
What can cause splenic enlargement?
Infection, congestion, haematological/ inflammatory/storage diseases
What is the most common cause of hyposplenism? What does this require?
Splenectomy / immunisations
What are some causes of hyposplenism aside from splenectomy?
Coeliac disease, sickle cell disease, sarcoidosis
The features of hyposplenism are mainly caused by reduced what? What abnormality may be seen?
Red pulp / Howell-Jolly bodies
Howell-Jolly bodies are a sign of what?
Hyposplenism
Hyposplenism due to splenectomy may cause some immune deficiency, especially if what is the case?
It was taken out in childhood
What is the triad of hypersplenism?
Splenomegaly, fall in one or more cellular components of blood, correction of cytopenias by splenectomy
