Spleen Flashcards
Where is the spleen located in the body
In the left hypochondrium
Convex surface resting on diaphragm
visceral surface in contact with the stomach and left kidney
Normal weight of the spleen
150 g to 250 g
What is the length of the spleen
5 cm to 13 cm
What is an accessory spleen
Small nodule of splenic tissue found apart from the main body of the spleen
Percentage of population with accessory spleen
10%
When is the spleen palpable
When size over 14 cm
From where does the blood enter spleen
From the splenic artery which divides into the trabecular arteries and give rise to Central arterioles
Why is arterioles ends in the spleen unique
Because they form cords which lack endothelial lining which creates an open blood system with lose reticular connective tissue network lined by fibroblasts and macrophages
How is blood drawn from the spleen
Enters venous sinuses which goes into splenic vein and get back to general circulation
Percentage of red pulp in spleen
75%
What forms the red pulp
The cords and sinuses
What is the function of the Red pulp
Monitoring integrity of red blood cells
What is the white pulp
Lymphatic tissue surrounding central arterioles
What is the periarteriolar lymphoid sheath
It’s a Sheath that is found around the central material which contains T cells
Immune cells found in the white pulp
B cells
Which zones are rich in macrophages and dendritic cells
The marginal and the perifollicular zones
How fast is rapid blood circulation in the spleen
1 or 2 minutes
How slow is slow blood circulation through the spleen
30 to 60 minutes
Major functions of the spleen
Filtration of red cells
Quality control of red cells
Capture and destruction of blood-borne pathogens
Generation of adaptive immune responses
Should you worry if there’s enlarged spleen
Yes
Where do you feel “regular” splenomegaly
Under left costal margin
How far can you expect a massive splenomegaly to be felt
As far as the right iliac fossa
Hematological causes of splenomegaly
Chronic myeloid leukemia Chronic lymphocytic leukemia Acute leukemia Malignant lymphoma Primary myelofibrosis Polycythemia vera Hairy cell leukemia Thalassemia major or intermedia Sickle cell disease Hemolytic anemia’s Megaloblastic anemia
Causes of splenomegaly in portal hypertension
Cirrhosis
Hepatic or portal or splenic vein thrombosis
Storage disease causes of splenomegaly
Gauche disease
Niemann pick disease
Histocytosis x
InfectiousCauses of. Splenomegaly
Acute septicemia acute bacterial endocarditis Acute typhoid Acute infectious mononucleosis chronic tuberculosis Chronic brucellosis chronic syphilis chronic malaria chronic leishmaniasis Clinic schistosomiasis
Systemic disease causing splenomegaly
Sarcoidosis amyloidosis collagen disease systemic lupus erythematosus Rheumatoid arthritis systemic mastocytosis
Percentage of total red cell mess present in the spleen
5% or 30 to 70 mL
Portion of total marginating neutrophil pool in the spleen
Half
Percentage of platelet mass in the spleen
30%
Percentages of Retsil mess and platelets in an enlarged spleen
Can go up to 40% of red cell mass and 90% of platelets mass
What is Hypersplenism
Clinical syndrome with no specific causal mechanism but with an enlarged spleen with reduction of one or more cell lines in peripheral blood and normal or hyperplastic cellularity of the bone marrow
How do you confirm hypersplenism
By response to splenectomy
How do you treat Hypersplenism
Treat underlying cause of Hypersplenism or splenomegaly
Splenectomy shen severe anemia or benefits outweigh the risks
What are the risks of splenectomy
Sepsis
Thrombophilia
What is Hyposplenism
Medical condition Occurring due to the range of medical conditions or splenectomy
What conditions are associated with congenital absence of the spleen
Oregon transposition or severe malformations of the heart and lungs
What are some common causes of Hyposplenism
Asplenia Due to sickle cell anemia by one year of age and auto infarction at 6 years of age
Congenital absence of the spleen
Atrophy of the spleen by 65 years of age
Splenectomy sickle cell disease essential thrombocythemia adult gluten induced enteropathy dermatitis herpetiformis Amyloidosis Rarely inflammatory bowel disease splenic arterial thrombosis
What is the risk of hyposplenism for patients
Increased risk of infection especially by strep pneumonia ,Haemophilus influenza type B , Neisseria meningitides
Severe form of malaria
Red cells features in Hyposplenism
Target cells Acanthocytes Irregularly contracted or crenated cells Howell jolly bodies Siderotic granules Pappenheimer bodies
White cell features of Hyposplenism
Miles lymphocytosis
monocytosis
Platelets features of Hyposplenism
Thrombocytosis
What prevention measures must be taken by patients with Hyposplenism
Information about susceptibility to infection
carry cards about condition
prophylactic oral penicillin
erythromycin if patient allergic to penicillin
vaccination against pneumococcus Haemophilus meningococcus influenza
