L3.13 Mediators of Acute Inflammation

Question 1

What are the kinds of replication?

Answer 1

Labile: constantly replicating (skin, gut lining)
Stable/facultative: can be stimulated to enter cell cycle (melanocytes, hepatocytes)
Permanent: don’t enter cell cycle (cardiac myocyte, neuron)

Question 2

What are the features of granulation tissue?

Answer 2

Generates scar tissue, present at 3-4 days, degrades basement membrane and recruits parasites

Question 3

What are the types of healing?

Answer 3

Healing by primary intention: wound edges are close together and healing time is quick and may not leave a scar
Healing by secondary intention: more granulation and scar tissue

Question 4

What are the features of growth factor action?

Answer 4

Released by many cell types and activate tyrosine kinase receptors to cause transcription factor replication and cell cycle

Question 5

What are the patterns of intracellular signalling?

Answer 5

• Juxtacrine: Occurs when the cells are adjacent to each other - separated by junction
• Autocrine: signalling to self
• Paracrine: Cell releases factors that act on adjacent cells that are of a different cell type
• Endocrine: signalling through blood

Question 6

What are the outcomes of acute inflammation?

Answer 6

Resolution: tissue returns to normal
Repair: scar tissue formed
Chronic inflammation: event continues
Abscess: lots of neutrophils and necrosis, can lead to chronic inflammation