Cell Pathology 2 Flashcards

1
Q

What is oedema?

A

Abnormal increase in interstitial fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What maintains interstitial fluid balance?

A
  1. Hydrostatic pressure (determined by BP)

2. Osmotic pressure (maintained by solutes in blood and interstitial fluid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give 5 causes of oedema?

A
  1. Increased hydrostatic pressure.
  2. Salt & H2O retention
  3. Reduced plasma osmotic pressure
  4. Lymphatic obstruction
  5. Inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is generalised oedema?

A

Widespread fluid accumulation in subcutaneous tissues and serous cavities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name 1 factor for generalised oedema?

A

Renin-angiotensin-aldosterone pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is seen in the skin of patients with generalised oedema?

A

Pitting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List the causes of generalised oedema.

A
  1. LV failure
  2. Nephrotic syndrome (kidney damage)
  3. Hepatic failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What causes pulmonary oedema?

A

Raised hydrostatic pressure in the pulmonary capillary bed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the most common cause of pulmonary oedema?

A

LV failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How can LV failure cause pulmonary oedema?

A
  1. Inadequate removal of blood from pulmonary circulation.
  2. Pressure builds up in pulmonary circulation.
  3. Fluid accumulates in alveolar interstitium. Eventually moves into alveolar space - poor gas exchange.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the main symptom of pulmonary oedema?

A

Breathlessness (dyspnoea), usually worse when lying flat (orthopnoea).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is one more susceptible to pneumonia if they have pulmonary oedema?

A

Fluid in the alveolar space predisposes the lungs to bacterial infection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes cerebral oedema?

A
  1. Disruption of blood flow to cerebral capillaries

2. Causes pressure buildup in blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where is cerebral oedema seen?

A

In brain tissue surrounding lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give 4 lesions in the brain

A

Contusion, haemorrhages, infarcts (stroke) and tumours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Increase in fluid in the brain causes what.

A
  1. Increased inter cranial pressure.

2. High ICP increases risk of herniation and death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How should cerebral oedema be treated?

A
  1. Raise the head (allows gravity to drain fluid).
  2. Infuse isotonic fluids (replenish lost fluid from blood)
  3. Infuse steroids and osmotic diuretics (Eg mannitol) - gets fluid back into blood
  4. Surgical decompression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a thrombosis?

A

Abnormal blood clot formation in the circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 factors that cause thromboses?

A
  1. Blood stasis
  2. Vessel wall injury
  3. Hypercoagulability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the main factors in venous thrombosis?

A

Stasis and hyper coagulability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why do most venous thromboses occur in deep leg veins?

A
  1. Blood may be hyper coagulable.
  2. Venous BP is much lower than arterial BP.
  3. Therefore blood may stop flowing, especially in legs (as working against gravity).
  4. In periods of non-movement, thromboses may occur (as muscle contraction in legs are major factor for pushing blood back upto heart).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the main cause of arterial thromboses?

A

Atherosclerotic plaque, which causes vessel wall injury.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the most important potential complication of a VT.

A

Pulmonary embolism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How can an Arterial thrombosis cause ischaemia or Infarction?

A

Arterial wall narrows (stenosis), because thrombus blocks the wall.

25
Q

What causes cardiac thrombosis?

A

Stasis of blood.

Stasis is caused by cardiac fibrillation - irregular depolarisation and contraction means blood isn’t moved (as efficiently) - so blood remains static

26
Q

Left atrial thrombosis is usually related to…?

A

Atrial fibrillation

27
Q

Left ventricular thrombosis is usually related to….?

A

Prior myocardial infarction.

28
Q

What is the most important potential complication of cardiac thrombosis?

A

Systemic embolisation.

29
Q

What is an embolus?

A
  1. Detached mass within blood.
  2. Carried to distant site from point of origin.
  3. Most emboli are dislodged thrombus - thromboembolism.
30
Q

Give rare types of emboli.

A

Fat, air, amniotic fluid, tumour.

31
Q

Why are emboli dangerous?

A

They can lodge in vessels and block them off.

32
Q

What is a venous thromboembolism?

A

An embolus (usually DVT) lodging itself in an artery.

33
Q

What is the most serious consequence of a pulmonary thromboembolism.

A

Embolism to lung which blocks off pulmonary artery - instant death.

34
Q

How can a pulmonary thromboembolism cause instant death?

A
  1. No blood flow through lungs.

2. Puts immense pressure on right side of the heart

35
Q

What are the symptoms of pulmonary embolism?

A
  1. Difficulty breathing
  2. Chest pain on inspiration
  3. Palpitation
36
Q

What are the clinical signs of pulmonary embolism?

A
  1. Low blood oxygen saturation and cyanosis
  2. Rapid breathing
  3. Rapid heart rate

(SEVERE CASES)

  1. Collapse
  2. Very low BP
  3. Sudden death
37
Q

People with emboli in medium sized arteries present with?

A

Breathlessness

38
Q

Emboli in small arteries cause subtle symptoms of..?

A

Breathlessness, chest pain and dizziness.

39
Q

Where do arterial thromboembolism originate from?

A

Heart or carotid arteries.

40
Q

What may arterial thromboembolism cause?

A

Impact:

Cerebral arteries - stroke

Mesentric arteries - bowel infarction

Lower limbs - acute lower limb ischaemia

41
Q

What is an infarction?

A

Tissue necrosis due to ischaemia (lack of blood reaching tissue leads to tissue death)

42
Q

What causes an infarction.

A

Usually caused by occlusion of an artery (sometimes veins) due to an embolus.

43
Q

How do infarcts heal?

A

Usually they heal by repair. However, there is loss of functional tissue as dead tissue replaced by scar tissue.

44
Q

What artery do MI almost always involve?

A

Left anterior descending coronary artery.

45
Q

Cerebral infarction is usually confined to one hemisphere. T or F?

A

T.

46
Q

How is small bowel infarction caused?

A

Thromboembolus to bowel via superior mesenteric artery.

47
Q

What can hypovolaemic hypotension (caused by loss of blood to gut) lead to.

A

Hypovolaemic shock and sepsis because gut flora can invade into blood.

48
Q

What is haemorrhage?

A

Leakage (extravasation) of blood due to rupture.

49
Q

What causes a haemorrhage?

A
  1. Trauma

2. Intrinsic disease of blood vessel - leads to weakening of wall

50
Q

Major blood vessel rupture can lead to acute haemorrhage. What are the associated risks.

A
  1. Hypovolaemia (decreased blood volume)
  2. Shock
  3. Death
51
Q

Small vessel ruptures can also be fatal. Eg, where?

A

Eg brainstem haemorrhage.

52
Q

What is shock?

A

Generalised tissue perfusion failure (aka blood not sufficiently providing oxygen/nutrients to tissues)

53
Q

What is shock caused by?

A
  1. Pump failure

2. Peripheral circulation failure (e.g. hypovolaemia, sepsis, anaphylaxis)

54
Q

What can circulatory collapse lead to?

A

Ischaemia of multiple organs.

55
Q

What are the most vulnerable organs to shock?

A
Kidneys
Bowel
Brain
Lung
Heart
56
Q

Why can shock lead to multiple organ failure?

A

It has a positive feedback mechanism - condition gets worse once in shock.

Need rapid treatment.

57
Q

What are the complications arising from shock?

A
  1. Multiple organ failure.
  2. Ischaemic tissue - lactic acidosis
  3. Acute tubular necrosis
58
Q

What are the diseases caused by stable atherosclerotic plaques?

A
  1. Stable angina

2. Chronic lower limb ischaemia