Leucocytes and inflammation

Question 1

What is the role of the cells, tissues and molecules in the immune system?

Answer 1

To mediate the protection against infection

Question 2

What happens to a blood stem cell in its change to a mature cell?

Answer 2

Increased specialisation (commitment to a particular lineage)
Decreased plasticity (become less able to change cell type in response to changes in environment)

Mature cell enters blood stream from bone marrow
T-lymphocytes mature in the thymus gland

Question 3

Describe the cells within the myeloid lineage of leucocytes.

Answer 3

Eosinophils- kill antibody coated parasites

Macrophages- cause phagocytosis, activate bactericidal mechanisms, antigen presentation

Dendritic cells- antigen presentation in lymph nodes, antigen uptake in peripheral sites

Mast cells- release granules containing histamine

Question 4

Describe the cells within the lymphoid lineage of leucocytes.

Answer 4

T-lymphcytes- deal with intracellular infections e.g. viruses
B-lymphocytes- deal with extracellular infections e.g. bacteria

Question 5

What happens in juxtacrine signalling? Whats the relevance of this in inflammation?

Answer 5

Antigen bind to specific receptor on cell
This increases ligand expression on cell 1
Receptor for ligand on cell 2 stimulates function.

Question 6

What causes systemic inflammation?

Signs?

Answer 6

Cytocrine secret into circulation, so has an effect on distant tissues.

Fatigue, fever, loss in muscle/fat, pain, anorexia

Question 7

Describe the effect IL-1/IL-6/TNF-a have on the liver.

Answer 7

Acute phase proteins

Activation of compliment opsonisation

Question 8

Describe the effect IL-1/IL-6/TNF-a have on the bone marrow endothelium.

Answer 8

Neutrophil mobilisation

Phagocytosis

Question 9

Describe the effect IL-1/IL-6/TNF-a have on the hypothalamus.

Answer 9

Increased body temperatures
Leads to 
1. decreased viral and bacterial replication
2. increased antigen presentation
3. specific immune response

Question 10

Describe the effect IL-1/IL-6/TNF-a have on fat/muscle.

Answer 10

Fat and energy mobilization to allow increased body temperature
Leads to
1. decreased viral and bacterial replication
2. increased antigen presentation
3. specific immune response

Question 11

What is lymphoid tissue?

Answer 11

A collection of leucocytes which serve as a meeting point for cells of the immune system.

Question 12

Define a cytokine.

How are they specific

Name a chemokine and its function.

Answer 12

A small protein that acts as a signalling molecules between cells.

DIfferent protein structure
Different receptors
Involved in temporal and spatial organisation

CXCL8 attracts neutrophils to a site of infection.