Haemopoiesis, The Spleen And Bone Marrow ILOs

Question 1

What is haemopoiesis?

Answer 1

Formation of blood cells from bone marrow

Question 2

Bone marrow distribution in infants

Answer 2

All throughout the skeleton

Question 3

Bone marrow distribution in Adults

Answer 3

Limited
Pelvis, skull, ribs, sternum and vertebrae

Question 4

Haemopoiesis in the embryo

Answer 4

IN vasculature of the yolk sac to start
Then in the foetal liver between weeks 5-8

Question 5

Haemopoiesis starts off with Haematopoietic stem cells:
They differentiate into 2 cell types:

Answer 5

Common Myeloid Progenitor Cells
Common Lymphoid Progenitor Cells

Question 6

Common Myeloid Progenitor cells differentiate into 3 Types of cell:

Answer 6

Megakaryocytes
Erthryocytes
Myeloblasts

Question 7

Myeoblasts differentiate into:

Answer 7

Granulocytes: Neutrophils, Eosinophils and Basophils
AND
Monocytes

Question 8

Common Lymphoid Progenitor cell differentiations into 2 different lymphocytes

Answer 8

T-Lymphocytes
B-Lymphocytes

Question 9

T-Lymphocyte development

Answer 9

In foetal liver and Thymus

Question 10

B-Lymphocyte development

Answer 10

Foetal liver and Bone Marrow

Question 11

Erythropoiesis

Answer 11

Formation of red cells

Question 12

Protein Secreted by the KIDNEY to stimulate erythropoiesis

Answer 12

Erythropoietin

Question 13

Thrombopoiesis

Answer 13

The formation of Thrombocytes (Platelets)

Question 14

Thrombopoietin function

Answer 14

Protein that simulates formation of Megakaryocytes therefore stimulates THROMBOPOIESIS

Question 15

What is a THROMBOCYTE?

Answer 15

Important in blood clotting
Membrane bound cytoplasm that has budded off from a Megakaryocyte

Question 16

Granulopoiesis

Answer 16

Formation of Granulocytes (Neutrophils, Eosinophils and Basophils) from Myeloblast cells which originate from Common Myeloid Progenitor Cells

Question 17

Monocytopoiesis

Answer 17

Production of monocytes from Myeoblasts which originate from Common Myeloid Progenitor Cells
Monocytes differentiate into either MACROPHAGES OR DENTRITIC CELLS

Question 18

Macrophage function

Answer 18

Phagocytose foreign substances in the body

Question 19

DENTRITIC Cells

Answer 19

Antigen presenting cells
Present the antigens of pathogens they have engulfed to Lymphocytes

Question 20

Erythrocyte function

Answer 20

Transport Oxygen from lungs to tissues by carrying haemoglobin
Transport CO2 form the tissues back to the lungs

Question 21

Erythrocyte Structure

Answer 21

No nucleus
Bioconcave
No mitochondria
Lipid bilayer contains proteins that maintain the structure of the cell so that it remains bioconcave and flexible

Question 22

Hereditary Spherocytosis

Answer 22

A gene mutation of at least one of the proteins that is responsible in maintaining phospholipid bilayer of the erythrocyte and therefore its bioconcave shape

Question 23

Spleen function

Answer 23

A filter of the blood

Question 24

Spleen general structures

Answer 24

Splenic Artery (Brings BLood To Spleen)
Red Pulp = Sinusoids containing Macrophages RED Cells Pass through it
White Pulp = Plasma and white cells pass through it
Splenic vein
Splenic artery linked to splenic vein by a portal system

Question 25

BLood Pooling in the SPleen

Answer 25

RED Cells and platelets accumulate in the spleen so they can be quickly mobilised during bleeeding

Question 26

WHite pulp importance

Answer 26

Lots of antibodies synthesised here Removes antibody covered bacteria and RBCs

Question 27

Red Pulp Importance

Answer 27

Macrophages engulf and destroy old RBCs here

Question 28

Extramedullary Haemopoiesis

Answer 28

When haemopoiesis occurs not in the bone marrow E.g: Spleen and Liver Can cause Splenomegaly

Question 29

What is Splenomegaly?

Answer 29

Enlarged Spleen

Question 30

Splenomegaly is caused by

Answer 30

-Extra-medullary Haemopoiesis -Hypertension of hepatic portal vein from liver disease (blood can’t leave spleen) -Overwork of spleen (causes increase in pulp size) -Expanding as infiltrated by cells (Blood cancers/Leukeamia) -Expanding as infiltrated by materials (Sarcoidosis)

Question 31

Dangers of Splenomegaly

Answer 31

Spleen no longer fully protected by rib cage, risk of rupture Need to avoid contact sports

Question 32

Hyposplenism is

Answer 32

Lack of functioning splenic tissue

Question 33

Hyposplenism caused by

Answer 33

Splenectomy Sickle cell disease ( Red cells not bioconcave, get stuck in spleen) Gastrointestinal diseases (ulcerative colitis, Crohns Disease and coeliac disease) Autoimmune disorders (Rhuematioid Arthiritis and Hashimotos Disease)

Question 34

Hyposplenism = BIG RISK OF

Answer 34

SEPSIS Encapsulated bacteria very hard for immune system to combat without maximum splenic function

Question 35

Indication of Hyposplenism

Answer 35

Presence of Howell Jolly Bodies in Blood Film Normally are removed

Question 36

Normal Range

Answer 36

Includes 95% of population Values outside range not always abnormal Results may be in normal range but it may be a significant change within the normal (this is abnormal) Normal range changes with age, sex and comorbidities

Question 37

Significance of reticulocyte count

Answer 37

Indication of production of erythrocytes and therefore activity of the bone marrow

Question 38

Haematocrit (HcT)

Answer 38

Proportion of blood that is made up of red blood cells

Question 39

Haemoglobin Concentration

Answer 39

A Parameter for accessing Full Blood Counts

Question 40

Red Cell Count (RCC)

Answer 40

Number of Red Cells in a given vol of blood

Question 41

Mean Cell Volume (MCV)

Answer 41

Helps determine cause of anaemia

Question 42

Red Cell Distribution Width (RDW)

Answer 42

Variation in size or red blood cells Helps determine the stage of anaemia So if anaemia has just started there will be a wide range of sizes If its been happening a long time, all cells would be small so RDW is low since they are all similar

Question 43

Mean Cell Haemoglobin (MCH)

Answer 43

Average amount of haemglobin in a RBC Used to asses

Question 44

Microcytic

Answer 44

Small MCV (Mean Cell Volume)

Question 45

Macrocytic

Answer 45

High MCV (Mean Cell Volume)

Question 46

Anisocytosis

Answer 46

Increased variation non red cell size (RDW Red Cell Distribution Width)

Question 47

Hypochromic

Answer 47

Low Mean CEll Haemoglobin

Question 48

Hyperchromic

Answer 48

High Mean Cell Haemoglobin (MCH)

Question 49

Dimorphism

Answer 49

2 distinct populations of red cells

Question 50

Polychromatic

Answer 50

Reticulocytes

Question 51

Megakaryocyte function

Answer 51

Produce Thrombocytes

Question 52

Eosinophils FUnction

Answer 52

MEdiator of allergic responses Immune response to parasites

Question 53

In appropriate activation of eosinophils

Answer 53

Causes inflammation (asthma) and tissue damage

Question 54

Basophils

Answer 54

Active in allergies and inflammatory conditions

Question 55

Lymphocytes

Answer 55

B Cells make antibodies T Cells (Produce T cell receptors to recognise antigens) Natural Killer Cells