6 MEH

Question 1

Which 2 different cellular populations make up the spleen?

Answer 1

1. Red pulp: sinuses lined with endothelial macrophages and cords
2. White pulp: similar to lymphoid follicles

Question 2

What is the function of the red pulp of the spleen?

Answer 2

The red pulp of the spleen removes old red cells and metabolises the haemoglobin

Question 3

What is the function of the white pulp of the spleen?

Answer 3

The white pulp synthesises antibodies and removes antibody-coated bacteria and blood cells.

Question 4

Through which vessel does blood reach the spleen?

Answer 4

Splenic artery

Question 5

What are the 4 general roles of the spleen as a whole?

Answer 5

1. Sequestraton and phagocytosis of old/abnormal red cells by macrophages
2. Blood pooling from which platelets and red cells and be rapidly mobilised during bleeding.
3. Extramedullary haematopoiesis - pluripotent stem cells proliferate during haematological stress or if marrow fails EG. Myelofibrosis
4. Immunological function - 25% of T cells and 15% of B cells are present in the spleen, these leukocytes are present and monitor in the white pulp looking for infection.

Question 6

What is splenomegaly?

Answer 6

Enlargement of the spleen

Question 7

Splenomegaly is typically associated with what?

Answer 7

Enlargement of the spleen is typically associated with increased workload-
(Eg. Haemolytic anaemia)

Question 8

Name some causes for splenomegaly.

Answer 8

1. Haemolytic anaemia - increased number of defective blood cells are removed from the circulation
2. Congestion due to portal hypertension
3. Infiltration by leukaemias/lymphomas
4. Expansion due to accumulation of waste products of metabolism (Eg. Gaucher’s disease)

Question 9

Wat is Gaucher’s disease?

Answer 9

It is an enzymatic defect of beta-glucosidase enzyme.This enzyme catalysts the breakdown of glucocerebroside which is a constituent of red and white cell membranes.
So Glucocerebroside will accumulate in fibrils in the spleen

Question 10

What is hyposplenism?

Answer 10

Reduced splenic fucntion

Question 11

With which clinical condition is hyposplenism associated?

Answer 11

An increased risk of overwhelming sepsis.

Question 12

What are common causes for hyposplenism?

Answer 12

Diseases that destroy spleen tissue:

1. Sickle cell
2. Coeliac disease
3. Splnectomy after trauma or tumour

Question 13

A blood film form a hyposplenism patient has one ver typical characteristic, what is it?

Answer 13

Howell Jolly bodies

• they are basophilic nuclear remanants (clusters of DNA) in ciculatng RBCs
• they appear like small purple dots in the RBCs

Question 14

What is cytopenia?

Answer 14

It is used to describe a reduction in the number of blood cells.
it can take a number of forms:
- anaemia
- leukopenia
- neutropenia 
- thrombocytopenia
- pancytopenia

Question 15

What is pancytopenia?

Answer 15

It is a combination of low red cells, white cells and platelets

Question 16

What do the suffixes -cytosis and -philia signify in the context of blood cell number?

Answer 16

An increase

Eg. Erythrocytosis, leucocytosis, neutrophilia, lymphocytosis, etc.

Question 17

What is another term for leukocytes?

Answer 17

white blood cells

Question 18

What is a major difference between leukocytes and RBCs or platelets?

Answer 18

Leukocytes have a nucleus

Question 19

What is the most common cause of splenomegaly worldwide?

Answer 19

Malaria

• the red cells will have inclusions which here are parasitic
• the plane starts to remove the RBCs, so recruit more and more macrophages

Question 20

Is the spleen ever palpable when not pathological?

Answer 20

No! It is never normal to palpate the spleen

Question 21

Where does one palpate for an abnormal spleen?

Answer 21

Starts in the right iliac foss, then move p towards the upper left quadrant.