Lecture 2 - Inflammation

Question 1

what is the purpose of inflammation?

Answer 1

first line of defence in response to cell injury
it neutralises the agent causing injury
stops further cell injury
cleans up injury site to promote healing

Question 2

what are the 5 clinical manifestations of inflammation?

Answer 2

1. redness
2. warmth
3. swelling
4. pain
5. loss of function

Question 3

what is the first stage of the inflammation response?

Answer 3

Vasodilatory response which increases blood flow to area by dilating arterioles and increasing permeability to allow plasma to move into interstitial fluid.

Question 4

what is the cause of redness and swelling at the site of injury?

Answer 4

increased blood flow to area

Question 5

what is the cause of swelling at the injury site?

Answer 5

increased permeability = increased plasma in interstitial fluid

Question 6

what is the cause of pain at site of injury?

Answer 6

increased swelling = increased tissue pressure = stimulation of nociceptors

Question 7

what are the 3 main types of cascades caused by plasma proteins entering the tissue site during the inflammation process?

Answer 7

1. Complement system
2. clotting cascade
3. kinin-kallikrein system

Question 8

what is the complement system?

Answer 8

a defensive system of 30+ proteins that circulate in the blood serum and kill microbes

Question 9

what are the 3 ways the complement system kills microbes?

Answer 9

1. opsonization - uses opsonins to tag foreign pathogens for elimination by phagocytes.
2. inflammation
3. cytolysis - dissolution or disruption of cells

Question 10

what is the purpose of the clotting cascade and how is it activated?

Answer 10

forms fibrin meshwork around site of injury to trap causative agent and prevent spread of damage

activated by proteolytic enzymes, collagen or bacterial toxins

Question 11

what is the main activator of the kinin-kallikrein system?

Answer 11

clotting factor XII which is made in the coagulation process = leads to kallikrein production

also produces chemical mediators (kinins) which are involved in vasodilation, increased vascular permeability or chemotaxis)

Question 12

what role to WBCs have in the inflammatory response?

Answer 12

phagocytes netutralise injurious agent and recruit other cells such as neutrophils (first to scene) and macrophages (remain for longer periods)

release pyrogens (fever starters) to create inhospitable environment

Question 13

what are the role of neutrophils in the inflammatory response?

Answer 13

Phagocytosis

Question 14

what are the role of monocytes (blood) and macrophages (tissues) in the inflammatory response?

Answer 14

sustained phagocytosis, produce cytokines, initiate healing, activate anitgens

Question 15

what are the role of eosinophils in the inflammatory response?

Answer 15

mediate allergic reactions

Question 16

what are the role of basophils(blood) and mast cells (tissues) in the inflammatory response?

Answer 16

concentrated source of histamine, mediate allergy

Question 17

what are the role of lymphocytes in the inflammatory response?

Answer 17

Immune responsiveness, antibody production, immune memory

Question 18

what causes exudate and what is its purpose?

Answer 18

when fluid moves out of blood vessels and accumulates in tissues during vascular phase

helps transport cells and plasma components to tissues to hekp healing

Question 19

what are the four main types of exudate?

Answer 19

1. Serous
2. Fibrinous
3. Purulent
4. Hemorrhagic

Question 20

describe serous exudate

Answer 20

watery and low protein (skin blister)

Question 21

describe fibrionous exudate

Answer 21

high plasma protein and formation of fibrin

Question 22

describe purulent exudate

Answer 22

contains pus which is cellular debris
caused by bacterial infection

Question 23

describe haemorrhagic exudate

Answer 23

has large number of RBCs - indicates large degree of tissue damage

Question 24

what is chronic inflammation

Answer 24

when a response lasts for 2 or more weeks as it cannot neutralize or kill infectious agent

caused by inhaled particles, chemicals, splinters, glass etc

Question 25

what is fibrosis?

Answer 25

when a chronic/persistent inflammatory process results in lots of fibrous formation which can lead to scarring and deformity

Question 26

what is granulomas?

Answer 26

when macrophages cluster around indigestible agent

Question 27

what type of necrosis can occur from calcified collagen fibres?

Answer 27

liquefactive necrosis as cells die from lack of gas exchange

e.g. TB or inflammatory bowel disease

Question 28

what are the four stages of wound healing?

Answer 28

1. scab formation from fibrin clot
2. debridement - as area is cleaned by macros and neutrophils
3. epithelialization - epithelial layer grows to form more permanent bridge
4. granulation tissue - new connective tissue grows into wound with new collagen fibers, capillaries and lymphatic vessels (indication of good healing)

Question 29

what causes keloid scars?

Answer 29

excessive collagen synthesis by fibroblasts

Question 30

how does wound contraction work?

Answer 30

myofibroblasts arrange connections between themselves and neighbouring cells to draw edges of the wound close and reduce the area