Blood cells and haematopoesis (rest look at Callum Esa 1)

Question 1

What is produced in the bone marrow?

Answer 1

RBC, platelts and most white blood cells

Question 2

A multigenic haematopoietic stem cell (hemocytoblast) can differentiate into which two progenitor cells?

Answer 2

Common myeloid progenitor

Common lymphoid progenitor

Question 3

What types of cells does a common myeloid progenitor differentiate into?

Answer 3

Megakaryocyte -> thrombocytes (platelets)
Erythrocyte
Mast cell
Myeloblast -> granulocytes and monocyte

Question 4

What types of cells does a common lymphoid progenitor differentiate into?

Answer 4

Small lymphocyte -> B and T lymphocytes

Natural killer cell

Question 5

What are the functions of the globin chains of haemoglobin?

Answer 5

Protect haem molecule from oxidation
Confer solubility
Permits variation in oxygen affinity (shape change)

Question 6

The mutation to the haemoglobin molecule that cause HbS changes the affinity of haemoglobin for oxygen. What is its affect on an oxygen dissociation curve?

Answer 6

Shifts it to the right -> lower afinity for oxygen

Question 7

When does the switch from fetal to adult haemoglobin occur?

Answer 7

3-6 months of age

Question 8

What are the two main metabolic pathways in red cells?

Answer 8

1. Glucose metabolised to lactate, ATP produced

2. Pentose phosphate pathway, generates NADPH

Question 9

What are the salient histological features of platelets?

Answer 9

Anuclear cell fragements, 2-3um in diameter

Question 10

What are the salient histological features of Megakaryoctes?

Answer 10

Large cells iwth multi-lobular nucleus and platelets budding off

Question 11

Where are most platelets stored?

Answer 11

Spleen

Question 12

What is the first thing that happens when damage occurs to blood vessels?

Answer 12

Platelet plug

Question 13

How do platelets adhere to damaged blood vessels?

Answer 13

Damaged blood vessels have exposed glycoproteins such as vWF. Platelets adhere to these with receptors.

Question 14

What triggers the release of granules from platelets and what is their effect?

Answer 14

Binding of platelets to receptors in the area of damage releases these granules. One of the effects of the substances in these granules is to expose receptors on the platelet surface allowing them to bind other platelets and clotting factors -> activation of blood cascade.

Question 15

Name the three main types of lymphocytes

Answer 15

B cells

T cells - CD4+ (helper cells) and CD8+ (supresser cells)

Question 16

What membrane receptors do T cells carry?

Answer 16

receptors for Igs

Question 17

What membrane receptors do NK cells have?

Answer 17

receptors for Fc (part of an antibody)

Question 18

Once B cells have interacted with T cells and transformed into plasmablasts or memory cells within in the lymph nodes. What happens to the plasmablasts?

Answer 18

The plasmablasts migrate to the bone marrow and form plasma cells (Ig production)

Question 19

What three cells can T lymphocytes differentiate into?

Answer 19

T cytotoxic cells (CD8+)
Natural killer cells - large granular lymphocytes
T helper cells (CD4+)

Question 20

What is the response of a T supressor (CD8+) cell to a macrophage displaying antigens?

Answer 20

Recognises antigen and binds causing lysis (H2O2)

Question 21

What is the response of a T helper cells to a macrophage displaying antigens?

Answer 21

Binding causes differentiation into memory cells and effector cells (which release cytokines)