L5 - haemopoeisis

Question 1

Where are blood cells produced in the adult?

Answer 1

bone marrow

Question 2

What part of the body do we take bone marrow samples from?

Answer 2

the right iliac crest

Question 3

what hormone stimulates production of

a) granulocytes
b) lymphocytes

Answer 3

a) G-CSF

b) IL’s/TNF’s

Question 4

what system is responsible for the control and removol of blood cells?

Answer 4

reticuloendothelial system

Question 5

Which organ is mainly responsible for the removal of damaged or old red blood cells as well as many other blood cells?

Answer 5

Spleen

Question 6

Blood enters the spleen via the ______ artery, white cells and plasma then pass preferentially to the white pulp and red cells to the _____ pulp

Answer 6

splenic

red

Question 7

Apart from phagocytosis of old or damaged blood cells, give two other functions of the spleen in the adult

Answer 7

1) Blood pooling - Contains a reservoir of RBC’s and platelets that can be rapidly mobilised during bleeding (so don’t have to wait for marrow to produce)
2) Extramedullary haemopoeisis - Contains pluripotent cells which can make blood cells in times of haematological stress or if the marrow fails (myelofibrosis) - note spleen does haemopoeisis in foetus
3) Has an immunological function - is the largest lymphoid organ - contains loads od lymphocytes

Question 8

Give some clinical examples as to why we would see splenomegaly (enlargement of the spleen)

Answer 8

Portal hypertension - in liver disease, this restricts blood flow and causes a back up of pressure into the spleen
Thalassaemias - overworking red pulp
infection - overworking white pulp
Lymphoma - Cancer in spleen lymphoid
Sarcoidosis - increase in number of other cells infiltrating

Question 9

Splenomegaly can result in hypersplenism and also risk of rupture because it is no longer all protected by the rib cage. Explain hypersplenism

Answer 9

Enlarged spleen means more pooling of blood which results in a low blood count

Question 10

What is hypoesplenism?

Answer 10

Lack of functioning splenic tissue

Question 11

Give two causes of hyposplenism

Answer 11

splenectomy/coeliac disease/sickle cell disease

Question 12

What are hyposplenic patients at massive risk of?

Answer 12

sepsis

Question 13

which state of haemoglobin has a higher affinity for oxygen?

Answer 13

R state

Question 14

What causes haemolytic anaemia

Answer 14

anything that causes a reduction in RBC survival and thus anaemia

Question 15

During anaemia which hormone is produced by the kidney to stimulate synthesis in number of blood cells

Answer 15

erythropoietin

Question 16

Jaundice is a yelowing of the skin, what is it caused by?

Answer 16

excess RBC destruction causing excess bilirubin formation

Question 17

Define the following:

a) pancytopenia

b) anaemia

Answer 17

a) low level of RBC’s, white cells and platelets

b) low red blood cell count

Question 18

what are the clinical terms for:

a) high red cell count
b) high neutrophil count
c) high platelet count

Answer 18

a) erythrocytosis
b) neutrophilia
c) thrombocytosis
NOTE - increased number = cytosis apart from neutrophils only one in which it is philia

Question 19

what are the two major functions of a neutrophil?

Answer 19

phagocytosis and chemotaxis

Question 20

What can be given to patients with severe neutropenia to rectify the levels?

Answer 20

G-CSF

Question 21

give three causes of neutropenia

Answer 21

B12/folate deficiency / viral infection / aplastic anaemia / sepsis / splenic pooling

Question 22

Monocytes respond to inflammation, when would we see a monocytosis?

Answer 22

Chronic inflammatory conditions such as Crohn’s/ chronic infections/ carcinomas

Question 23

what do eosinophils respond to?

Answer 23

Parasites and are active in hypersensitivities

Question 24

What would the presence of Howell jolly bodies indicate?

Answer 24

hyposplenism - because a normal working spleen would filter these out