Spleen and tonsils Flashcards
What type of structure is the spleen?
Secondary/Peripheral lymphoid organ
What are the 2 key aspects of the spleen?
Diaphragmatic surface
Visceral surface
What structures are in contact with the visceral surface of the spleen?
Left kidney
Gastric fundus
Tail of pancreas
Splenic flexure of colon
What is the main arterial supply to the spleen?
Splenic artery (Branch of coeliac trunk)
What is the main venous drain of the spleen?
Splenic vein
What are the 2 types of tissue within the spleen?
Red pulp
White pulp
What does the red pulp of the spleen contain?
Sinusoids
Cords of Bilroth
Describe the structure of splenic sinusoids
They are fenestrated sinusoids, lined by epithelial cells and supported by hoops of reticulin
They become engorged with blood, hence red pulp
What is contained in the white pulp?
Peri-arteriolar lymphoid sheath (PALS) containing CD4+ lymphoid cells
Lymphoid follicles containing B cells
How do antigens reach the white pulp?
In the blood stream via APCs
What are the cords of Bilroth made up of?
Macrophages
Fibroblasts
Cells in transit (RBC, WBC, PC and some CD8+)
What are the 3 main features of hypersplenism?
- Splenomegaly
- Fall in one or more blood components (Cytopenia)
- Correction of cytopenia by splenectomy
What is splenomegaly?
Enlargement of the spleen
What are some types of causes of splenomegaly?
- Infection
- Congestion
- Haematological disease
- Inflammatory disorders
- Others
What are some infections that can cause splenomegaly?
- EBV
- Malaria
- TB
- Typhoid
- Brucellosis
- Leishmaniasis
What are some causes of splenic congestion?
Portal hypertension in hepatic cirrhosis and cardiac failure
What are some haematological diseases that can cause splenomegaly?
Lymphoma
Leukaemia
Haemolytic anaemia
Myeloproliferative disorders
What are some inflammatory disorder that can cause splenomegaly?
Rheumatoid arthritis
SLE
What are some ‘other’ diseases that can cause splenomegaly?
- Gaucher’s (Storage disease)
- Niemann-Pick disease (Storage disease)
- Amyloid
- Tumours
- Cysts
How will splenomegaly present?
Dragging sensation and discomfort in the LUQ, with possible eating pain in infarction and early satiety
What are some causes of splenic atrophy?
- Splenectomy
- Coeliac disease
- Sickle cell disease
- Sarcoidosis
What is the most common feature of splenic atrophy?
Reduced red pulp amount and function
What will blood film show in splenic atrophy?
- Howell-Jolly bodies
- Basophilic nuclear remnants
- Other red cell abnormalities
- Possible immune deficiency (Especially in childhood splenectomy)
What are tonsils?
Tonsils are like lymph nodes without a capsule
They contain germinal centres and follicles, but the capsule is replaced by stratified squamous epithelium with crypts
