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

LS1 Histology > Blood cells and haematopoesis (rest look at Callum Esa 1) > Flashcards

Flashcards in Blood cells and haematopoesis (rest look at Callum Esa 1) Deck (21)
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1
Q

What is produced in the bone marrow?

A

RBC, platelts and most white blood cells

2
Q

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

A

Common myeloid progenitor

Common lymphoid progenitor

3
Q

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

A

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

4
Q

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

A

Small lymphocyte -> B and T lymphocytes

Natural killer cell

5
Q

What are the functions of the globin chains of haemoglobin?

A

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

6
Q

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?

A

Shifts it to the right -> lower afinity for oxygen

7
Q

When does the switch from fetal to adult haemoglobin occur?

A

3-6 months of age

8
Q

What are the two main metabolic pathways in red cells?

A
  1. Glucose metabolised to lactate, ATP produced

2. Pentose phosphate pathway, generates NADPH

9
Q

What are the salient histological features of platelets?

A

Anuclear cell fragements, 2-3um in diameter

10
Q

What are the salient histological features of Megakaryoctes?

A

Large cells iwth multi-lobular nucleus and platelets budding off

11
Q

Where are most platelets stored?

A

Spleen

12
Q

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

A

Platelet plug

13
Q

How do platelets adhere to damaged blood vessels?

A

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

14
Q

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

A

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.

15
Q

Name the three main types of lymphocytes

A

B cells

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

16
Q

What membrane receptors do T cells carry?

A

receptors for Igs

17
Q

What membrane receptors do NK cells have?

A

receptors for Fc (part of an antibody)

18
Q

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?

A

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

19
Q

What three cells can T lymphocytes differentiate into?

A

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

20
Q

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

A

Recognises antigen and binds causing lysis (H2O2)

21
Q

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

A

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