Unit 2- Inflammation

Question 1

What occurs internally when there is heat/ redness in an inflammatory response?

Answer 1

dilation of blood vessels/ arterioles (redness) leads to increased blood flow (heat)

Question 2

What is Vasodilation?

Answer 2

widening of blood vessels resulting from relaxation of smooth muscle cells affected by mediators (chemicals) released by immune cells and nervous activity in the peripheral nervous system

Question 3

What happens internally when the body swells in an inflammatory response?

Answer 3

Oedema- protein concentrate of the exudate is less than that of the blood.
Epithelial cells increase permeability of capillary walls in response to specific mediators (histamines/ cytokines)- they contract and allow fluid into the extracellular space.

Question 4

What are Nociceptors?

What are the three types?

Answer 4

Nerve endings that react to damaging stimuli and send signals to the spinal cord and brain (leads to perception of pain)

1. Mechanosensitive- stimulated by mechanical stress/ damage to tissues
2. Thermosensitive- stimulated by extremes of heat and cold
3. Chemosensitive- stimulated by chemicals, pH etc

Question 5

What are the benefits of Nociceptors?

Answer 5

• transmitted rapidly in sensory A nerve fibres
• Accurately localised- tells you a specific area in a small receptive field
• Affected by mediated released by immune cells

Question 6

Briefly describe the steps to Trans- endothelial cell migration?

Answer 6

1. Injury- Macrophages become activated & produce chemokines
2. Chemokines diffuse from the centre of cell activation to the capillaries- effecting blood flow and permeability
3. Neutrophil will change its shape & start sticking to epithelial cells in a process called ‘rolling’.

Question 7

What is trans endothelial cell migration?

Answer 7

where leukocytes move out of blood vessels in a well orchestrated series of steps in the absence of an endothelial cell injury

Question 8

Which cells activate platelets?

Answer 8

Thrombin (Part of coagulation cascade)
Phosphatidylserine (damaged cells)
Collagen exposed following endothelial cell damage

Question 9

What is the first line of defence in Acute Inflammation?

Answer 9

Tissue resident cells- degranulation of

mast cells at mucosal surfaces leads to release of histamine

Question 10

What is the second line of defence in Acute Inflammation?

Answer 10

Infiltration of Polymorphs
e.g. Neutrophils, Eisonphils, Basophils
highly phagocytic, contain preformed proteases

Question 11

What is the third line of defence in Acute Inflammation?

Answer 11

Monocytes
Clear dead host cells, highly phagocytic but also release mediators such as cytokines.
Express MHC molecules to kickstart adaptive immune response

Question 12

What is the fourth line of defence in Acute Inflammation?

Answer 12

Increased production- stimulation of progenitor cells in bone marrow by colony stimulating factors (CSFs)

Question 13

What is Systemic Inflammation and what is it caused by?

Answer 13

Chronic activation of immune system

Caused by cytokines being released into the circulation causing elevation of the set point of the hypothalamus

Question 14

What can Systemic Inflammation lead to?

Answer 14

Cytokine Storm- hyperproduction of cytokines leading to shock

Question 15

What are the three stages of wound healing?

Answer 15

1. Inflammatory- substrate [1-7 days]
2. Proliferative - repair phase [3014 days]
3. Maturation- remodelling phase [14+ days]

Question 16

What happens in the decline of the Inflammatory phase?

Answer 16

• loss of stimulus (therefore altered cell signalling)

- fewer inflammatory factors are secreted and macrophages are reduced at the wound site

Question 17

How do Macrophages aid in the Proliferation stage of wound healing?

Answer 17

secret growth factors
cytokines attract cells involved in proliferation
produce factors that induce angiogenesis

Question 18

What is Angiogenesis and what is it stimulated by?

Answer 18

formation of capillary buds to produce new blood vessels
stimulated by TGF-beta (transforming growth factor), FGF (fibroblast growth factor), and PDGF (platelet derived growth factor)

Question 19

How are Fibroblasts involved in tissue repair?

Answer 19

Migration & Proliferation of Fibroblasts via growth factors- fibroblasts synthesise the extracellular matrix and collagen (structural frameworks)

Question 20

What is Purulent/ Suppurative Inflammation?

Answer 20

persistent or excessive necrosis- normally induced by bacteria

Question 21

What can tissue necrosis lead to?

Answer 21

accumulation of pus in the cavity leading to granuloma formation

Question 22

What types of Granuloma are formed during necrosis?

Answer 22

1. Foreign body granuloma
2. Immune Granuloma
3. Abscess

Question 23

What are the consequences of Chronic Inflammation? (2)

Answer 23

1. Tissue Dysfunction- persistent infection leads to constant stimulation of immune system leading to Cortisol release (stress hormone) which affects metabolism
2. Neurodegenerative diseases- cytokines in the brain can affect neurotransmission