MoD Session 2- Acute Inflammation

Question 0

What is the purpose of acute inflammation? (3)

Answer 0

Deliver blood cells and fluid to:

• protect against infection
• clear damaged tissue
• initiate tissue repair

Question 1

Define acute inflammation.

Answer 1

It is the response of living tissue to injury that is innate, immediate, short lived and stereotyped.

Question 2

What controls the movement of leukocytes and fluid to the injury site?

Answer 2

Chemical mediators

Question 3

What are the 5 causes of acute inflammation?

Answer 3

• microbial infection
• tissue necrosis
• physical and chemical agents
• hypersensitivity reactions
• foreign bodies

Question 4

What are the five clinical signs of acute inflammation? (And their equivalent Latin names)

Answer 4

Redness, swelling, heat, pain, loss of function

Rubor, Tumor, calor, dolor

Question 5

What changes occur to blood flow in acute inflammation?

Answer 5

• arterioles initially constrict.
• arterioles and capillaries then dilate, therefore increasing blood flow. Rubor and calor.
• vessels are increasingly permeable, therefore fluid moves into tissues. Tumor.

Question 6

Why is fluid exudated in acute inflammation?

Answer 6

Because hydrostatic pressure increases and forces fluid out of vessels into surrounding tissues.

Question 7

What is exudate oedema?

Answer 7

Fluid loss into tissues shown in inflammation; it has a high protein content.

Question 8

What are the primary leukocytes involved in acute inflammation?

Answer 8

Neutrophils

Question 9

What does the presence of neutrophils in tissue indicate?

Answer 9

Injury

Question 10

Where are neutrophils produced?

Answer 10

Bone marrow

Question 11

What are the 8 steps of neutrophil emigration in acute inflammation?

Answer 11

• chemo taxis- chemotaxins summon neutrophils to damaged area.
• activation- chemotaxins bind to receptors and cause swelling by ion entry. Cells are more sticky.
• margination- leukocytes marginate in vessels
• rolling- stick to walls and roll along endothelium
• adhesion- stick
• diapedesis- dig themselves out of vessel.
• recognition and phagocytosis- attach to opsonins and phagocytose
• kill- oxygen dependent using free radicals, or oxygen independent using enzymes

Question 12

What are chemical mediators?

Answer 12

They are molecules that are produced during inflammation and modulate the inflammatory response somehow.

Question 13

What does histamine do?

Answer 13

It causes vasodilation and increased vascular permeability.

Question 14

What does bradykinin do?

Answer 14

It causes increased vasodilation and permeability of vasculature.

Question 15

What does the complement system do?

Answer 15

C3a and C5a come together to form a tube which punch holes in bacteria and cause them to die. They also generate C3b which aids phagocytosis.

Question 16

What do prostaglandins do?

Answer 16

They cause vasodilation and therefore increased blood flow.

Question 17

How do changes due to acute inflammation combat the injury? (4)

Answer 17

• vasodilation- increases temperature and blood flow
• fluid exudation- dilutes toxins and delivers nutrients, oxygen, plasma proteins etc to the site of injury
• loss of function and pain- enforces rest and therefore minimises the likelihood of further damage
• cell infiltration- removes dead and foreign material by phagocytosis.

Question 18

What are five local complications of acute inflammation?

Answer 18

• normal tissue damage
• compression of structures
• obstruction of tubes
• loss of fluid
• pain and loss of function

Question 19

What are the four systemic effects of acute inflammation?

Answer 19

• fever
• leukocytosis
• acute phase response
• shock

Question 20

How is acute inflammation resolved? (4)

Answer 20

• because mediators have short half lives they are degraded soon after their release.
• normal vascular tone and permeability returns.
• neutrophil emigration stops.
• exudate is taken back up into venules or drained via lymphatics.

Question 21

What is the sequelae of acute inflammation? (4)

Answer 21

• if damaged tissue tissue can regenerate, there will be complete resolution.
• if acute inflammation continues and some chronic occurs, an abscess forms.
• if damage is too extensive and chronic inflammation occurs, a fibrous scar will form.
• death