wk 3 - inflammation and repair

Question 1

define hyperaemia

Answer 1

increase in blood to an area, first thing to happen after an injury. active process. the passive process is congestion.

Question 2

define oedema and what is exudate

Answer 2

Excess fluid in interstitial fluid

exudate- rich in plasma proteins

Question 3

define effusion

Answer 3

oedema in a body cavity.

Excess fluid in body cavities

Question 4

define resolution

Answer 4

healing without scarring, restoration of structure and function

Question 5

define organisation

Answer 5

healing by scarring

Question 6

define ulcer

Answer 6

a lesion or sore on a body surface like the skin or mucous membrane. can be acute- if cause is removed/chronic- if not.

area of necrosis on the body surface

Question 7

define abscess

Answer 7

a lesion not on the bodys surface so the body walls it off and develops an abscess when it cannot be sloughed off like an ulcer can

area of necrosis trapped in a tissue or organ

Question 8

infections depend upon 3 factors

Answer 8

1. the host and its susceptibility/ response
2. site of infection
3. virulence - ability of microbe to cause disease

Question 9

what form of cell death causes an inflammatory response?

Answer 9

necrosis stimulates an acute inflammatory response

Question 10

physical indicators of acute inflammation and their causes 5

Answer 10

heat- hyperaemia
red - hyperaemia
swelling- oedema
pain- stretch receptors and chemical mediators
loss of function- oedema and pain

Question 11

what are the 3 features of acute inflammation?

Answer 11

1. hyperaemia,
2. oedmea
3. neutrophils

Question 12

what are the 3 possible outcomes of acute inflammation?

Answer 12

1. resolution- healing without scarring
2. organisation - healing by scarring (granulation tissue)
3. chronic inflammation

Question 13

what are the 3 main components of granulation tissue (immature scar tissue) and their role/purpose in repair?

Answer 13

1. macrophages- remove dead neutrophils, clean up debris
2. fibroblasts- secrete collagen
3. angiogenesis- new vessels grow and provide oxygen and nutrients

macrophages and fibroblasts leave.
scar tissue is made up of collagen and decreases over time.

Question 14

what are the consequences of healing through organisation?

Answer 14

replacing functional tissue with collagen that just fills in the gap.

loss of functional tissue

Question 15

what is meant by sterile and non sterile sites in the human body?

Answer 15

sterile- microbes shouldn’t be present. no portals to the environment.

non-sterile: where theres microbes apart of our innate immunity.

Question 16

what are the main differences between the innate and adaptive systems?

Answer 16

innate- fast, non specific, germline encoded

adaptive- slow, specific, memory

Question 17

what is the autoimmune response

Answer 17

when the immune system is targeting our self

Question 18

what is the hypersensitivity response

Answer 18

when the immune system is overreacting to something

Question 19

what is meant by immune-compromised and the patients at risk

Answer 19

immune system is impaired and not able to defend immunity to the standard level. makes patient susceptible to infection/disease

Question 20

what are the 3 outcomes of chronic inflammation

Answer 20

1. unresolved acute - cause isn’t removed and body walls off area
2. repeated acute
3. special cases- no acute phase, straight to chronic.

Question 21

chronic inflammation looks like

Answer 21

-later onset
-longer duration
-lymphocytes and macrophages
-involves further injury and repeated attempts to repair
-only way to heal is through organisation (scarring)

Question 22

acute inflammation looks like

Answer 22

early onset
short duration
involves fluid exudation and neutrophils
may result in resolution or organisation

Question 23

3 main features of chronic inflammation

Answer 23

1. continued injury/necrosis
2. repeated attempts to repair
3. lymphocytes- chronic inflammatory cell

Question 24

what types of cells does chronic inflammation involve 3

Answer 24

lymphocytes
macrophages
fibroblasts

Question 25

5 cardinal signs of acute inflammation and how are they related to vascular changes

Answer 25

red heat due to hyperaemia swelling due to hyperaemia and increased vascular permeability pain due to stretching of tissue by oedmea and stimulation of pain fibres loss of function due to oedema and pain

Question 26

what are the 3 microscopic features of acute inflammation and what are there roles

Answer 26

1. hyperaemia 2. oedmea 3. recruitment of neutrophils hyperaemia occurs, the increased permeability of vessels allows serum and proteins to enter affected tissue forming oedema (high protein=exudate). neutrophils are activated and attracted to the acutely inflammed tissue, they migrate through the vessel walls.

Question 27

examples of when the acute inflammatory process is life threatening

Answer 27

in the brain- odemea or a haemorrhage will cause an increase in intracanial pressure. Reduction in cerebrospinal fluid and decreased blood supply to the brain until the pressure leads to a herniation of the brain. the lungs/throat- swelling within the walls which can close the airway lumen leading to breathing difficulties the lungs- excessive iedema in the alveoli can impair gas exchange and place greater demands on the heart

Question 28

what type of oedema is in acute inflammation and how does it occur?

Answer 28

exudate, fluid high in proteins. In acute inflammation the hyperaemia results in increased hydrostatic pressure which forces fluid from the vessels into the tissue (transudate) but there is also increased vascular permeability which allows plasma proteins to also enter the fluid hence why we get an exudate. hyperaemia - increased hydrostatic pressure- increased vascular permeability - plasma proteins enter fluid - exudate

Question 29

what factors may prevent complete repair from occuring? (resolution)

Answer 29

1. permanent tissues (brain, heart) because cant divide 2.in labil/stable tissues, not possible when alot of tissue has been lost or there is overlying infection, poor immunity, poor nutrition or interuption of healing

Question 30

what happens to the heart in response to ischaemia

Answer 30

The infarcted tissue would stimulate the acute inflammatory response so there would be hyperemia, oedema and the infiltration of the tissue by neutrophils. Because the heart is a permanent tissue, the formation of granulation tissue would follow; macrophages will move into the necrotic tissue and continue to remove it along with the increasingly apoptotic population of neutrophils. Fibroblasts would migrate into the area and secrete collagen fibres to fill in the space once occupied by dead myocytes and new capillaries would sprout into the area to provide growth factors, oxygen and nutrients for the granulation tissue. Once the dead cells are removed and the tissue deficit filled with collagen, the macrophages and fibroblasts migrate away and the new capillaries regress (die of by apoptosis). As this is a case of organization as part of acute inflammation, the granulation tissue would mature into a collagen scar which contracts over time pulling the edges of parenchymal tissue together.

Question 31

positive and negatives of organisation

Answer 31

positive- allows repair, fills in tissue deficits for survival negatives- loss of tissue function, scar tissue contracts over time pulling surrounding tissue with it which can distort the surrounding parenchyma

Question 32

what are the 3 main features of chronic inflammation

Answer 32

1. Ongoing tissue injury and destruction 2. Lymphocytes 3. Repeated attempts at repair through the formation of granulation tissue and, when occurring in stable/labile tissues, proliferation of parenchymal cells.

Question 33

the link between inflammation and cancers

Answer 33

It is when cells are dividing & copying their DNA that they are most vulnerable to errors occurring. If you make the cells divide more, during to inflammation then there is greater risk for mutation and for that mutation to be passed onto daughter cells. In addition, to proliferation, during inflammation there is often increased levels of oxidants & other mediators capable of damaging DNA.

Question 34

following a myocardial infarction what type of inflammation and repair occurs

Answer 34

acute organisation

Question 35

why does chronic inflammation increase the risk of carcinoma formation

Answer 35

When chronic inflammation occurs in stable or labile tissues that contain epithelial cells, surrounding epithelial cells will proliferate (undergo hyperplasia) in a futile attempt to repair. This increase in proliferation & the presence of free radicals increases the chance of mutation. Note that it is not the granulation tissue that causes cancer.