Lymph nodes and spleen Flashcards
what are the sites of primary lymphoid tissue
bone marrow and thymus
what are the sites of secondary lymphoid tissue
lymph nodes spleen tonsils epitheliolymphoid tissue bone marrow
what are the functions of the lymphatic system
returns lymph to circulation in fluid homeostasis - prevents oedema
permits cell traffic and trapping
protective function
how can lymph node groups be examined
palpated in examination
radiologically
what are lymph nodes
small oval bodies located along the course of lymphatic vessels
what are lymphatic vessels
blind ending vascular channels that collect fluid and drain it to circulation
allow for passive movement of fluid
have valves to ensure unidirectional flow
afferent/efferent channels enter the lymph node
afferent channels bring lymph fluid into lymph nodes
afferent/efferent channels exit the lymph node
efferent
where do efferent channels drain
cisterna chyli / thoracic duct
Left or Right: jugular/subclavian/bronchomediastinal trunks
where does all lymph eventually drain to
left venous angle - thoracic duct (3/4 of body)
right venous angle - right lymphatic duct
what is contained at the hilum of lymph nodes
arterial and venous vessels
efferent channel
lymph is filtered through node parenchyma before entering the bloodstream true or false
true
the lymphoid system regulates the adaptive/innate immune system
adaptive immune system
which cells link the adaptive and innate immune systems
Antigen Presenting Cells APCs
which cells are found in lymph nodes
B cells - cortex T cell - paracortex Plasma cells - medulla macrophages, APCs, DCs endothelial cells
what is the difference between primary and secondary follicles in lymph nodes
secondary follicles contain a germinal centre
what is lymphadenopathy
enlarged lymph nodes
what are causes of lymphadenopathy
localised inflammation
systemic inflammation
malignancy: haematological and metastases
others: sarcoidosis, Castlemans disease, IgG4 related
what are local inflammatory causes of lymphadenopathy
infection
vaccination
dermatopathic
what are systemic inflammatory causes of lymphadenopathy
viral infection
autoimmune conditions
what is sarcoidosis
granulomatous condition
NOT a histological diagnosis
where do all lymph vessels of the head and neck drain to
deep cervical lymph nodes
what does generalised lymphadenopathy suggest
systemic inflammation or widespread malignancy
In autoimmune conditions, there is a predominant B cell/T cell/Phagocytic response
B cell response
When draining a tumour site, there is a predominant B cell/T cell/Phagocytic response
Phagocytic response
In viral infections or use of certain drugs (phenytoin), there is a predominant B cell/T cell/Phagocytic response
T cell response
what is the spleen
2ndary lymphoid tissue located in the LUQ of the abdomen
is the spleen usually palpable
no
only if significantly enlarged
the spleen is a very vascular structure, true or false
true!
describe the vasculature of the spleen
tortuous splenic artery from coeliac axis
splenic vein drains into superior mesenteric vein then portal vein
what is the function of the spleen
acts as a filter for blood, eliminates damaged/foreign materials
responsible in immune response to blood borne antigens
what 2 components make up the spleen’s parenchyma
red pulp
white pulp - mainly T cells
what makes up the red pulp in the spleen
sinusoids
cords: macrophages, fibroblasts, cells in transit
what is white pulp comprised of
Peri Arteriolar Lymphoid Sheath PALS
–> CD4+ T cells
what are symptoms of splenomegaly
dragging sensation in LUQ
eating discomfort
pain
what is the triad for hypersplenism
splenomegaly
decrease in >=1 cellular component of blood
correction of cytopaenias following splenectomy
causes of splenomegaly
infection congestion haematological inflammation storage diseases miscellaneous
what are infectious causes of splenomegaly
EBV TB Malaria Typhoid Brucellosis Leishmaniasis Trypanosomiasis
what are congestive causes of splenomegaly
Portal venous hypertension from:
liver cirrhosis
portal vein thrombosis
cardiac failure
what are haematological causes of splenomegaly
lymphoma leukaemia haemolytic anaemia ITP Myeloproliferative disorders
what are inflammatory causes of splenomegaly
SLE
Rheumatoid arthritis
What storage diseases can cause splenomegaly
Gaucher’s
Niemann Pick
What are miscellaneous causes of splenomegaly
amyloidosis
tumour
cysts
what can cause hypersplenism
conditions that cause splenomegaly
what can cause hyposplenism
sickle cell disease
coeliac disease
sarcoidosis
non-surgical iatrogenic
why is hyposplenism clinically important
reduced immune function and so patients need regular vaccinations/immunisations
what feature can be seen in reduced red pulp function
Howell Jolly bodies = basophilic nuclear remnants seen in RBCs
