Pathological Processes - Semester 2 Flashcards Preview

Semester 2 - MBChB - Leic Med > Pathological Processes - Semester 2 > Flashcards

Flashcards in Pathological Processes - Semester 2 Deck (347):
1

What is the difference between HISTOLOGY and CYTOLOGY?

HISTOLOGY - involves viewing tissue sections under microscope; cellular architecture and atypia are assessed; higher accuracy than cytology; more invasive
CYTOLOGY - non-invasive; fast, cheap and safe; used in preliminary testing; study of cells sucked out / scraped from an organ or extracted from a body fluid

2

What is the most commonly used fixative?

Formalin (formaldehyde in water)

3

What does a 'fixative' do?

Holds tissue in suspended animation
Inactivates tissue enzymes
Denatures proteins
Blocks autolysis
Hardens tissue
Prevents bacterial growth

4

What is used to embed the fixed tissue for histological examination?

paraffin wax

5

What is a 'microtome' used for in the preparation of a slide for microscopy?

Microtome cuts thin slices (3-4 microns thick) so that you can see through the sections using a microscope

6

What does H&E stand for?

haematoxylin
eosin

7

What does haematoxylin stain, and what colour?

Haematoxylin stains nuclei purple

8

What does eosin stain, and what colour?

Eosin stains cytoplasm, proteins, collagen and CT pink

9

In what situation might a frozen section be necessary instead of histology?

Time constraints - is this tissue cancerous or not?
The result will determine the course of the surgery.

10

How is a frozen section produced?

(bypass formalin fixation and paraffin wax embedding)
Rapidly freeze small fresh piece of tissue using the CRYOSTAT
Thinly slice the piece of tissue
Stain tissue
Mount and view using microscope

11

Give 4 causes of cell injury and death

Hypoxia (anaemia, ischaemia, histocytic, hypoxaemia)
Physical agents (trauma, radiation, electric currents)
Chemical agents and drugs (poisons, O2 extremes, alcohol)
Microorganisms
Immune mechanisms
Dietary insufficiency/excess
Genetic abnormalities

12

How does hypoxic injury occur?

Cell deprived of O2
Mitochondrial ATP production stops
Slowed down activity of ATP driven membrane ionic pumps
Na+ and H2O enter the cell
Cell swells, plasma membrane stretches
Glycolysis allows cell to stay alive temporarily (so increased lactic acid and decreased pH)
Heat shock response
Ca2+ enters cell, activating harmful enzymes (phospholipases, ATPase, endonucleases, proteases)
ER and other organelles swell
Enzymes leak out of lysosomes and attack cytoplasmic components
Blebbing
Cell dies (burst of bleb)

13

Why is it sometimes worse if blood returns to the tissue that has been ischaemic but isn't yet necrotic THAN if blood flow hadn't been restored?

Ischaemic-reperfusion injury

14

What is the mechanism of ischaemic-reperfusion injury?

Increased production of O2- free radicals with reoxygenation
More neutrophils, more inflammation and tissue injury
Delivery of complement proteins and activation of the inflammation pathway

15

Define "free radical"

Highly reactive, uncharged atom/molecule with a single unpaired electron in an outer orbit. Goes on to produce more free radicals. A reactive oxygen species with a single unpaired electron on the outer orbit.

16

How do free radicals injure cells?

Free radicals attack lipids in cell membranes, damage proteins, carbohydrates and nucleic acids. They are mutagenic.

17

How does the body defend itself against free radicals?

Antioxidant system
Vitamins A, C and E
Enzymes
Free radical scavengers
Storage proteins

18

What protein do cells release when they are injured (in order to protect themselves) and what does this protein do?

Heat shock proteins (e.g. ubiquitin)
Maintains protein viability and maximises cell survival

19

Characteristics of reversible cell injury under an electron microscope (3)

clumped chromatin
cell organelles swell
cytoplasmic blebs
ribosomes separate from the ER

20

Characteristics of irreversible cell injury under an electron microscope (3)

Increased cell swelling
karyolysis
membrane defects
lysis of ER
densities in swollen mitochondria
myelin figures

21

What is the difference between oncosis and necrosis?

Oncosis is the changes to the injured cell prior to death
Necrosis is the changes to the dead cell after it has been dead for some time

22

What is the difference between necrosis and apoptosis?

Necrosis - cell died with swelling; due to cell injury
Apoptosis - programmed cell suicide; cell died with shrinkage; regulated intracellular process where the cell itself degrades its own nuclear DNA and proteins

23

How is necrotic tissue removed from an area?

Phagocytosis by white cells
Enzymatic degradation
If some tissue remains, it calcifies - DYSTROPHIC CALCIFICATION

24

What are the four types of necrosis?

Coagulative
Liquifactive
Caseous
Fat

25

Name a disease that characteristically results in caseous necrosis

Tuberculosis

26

What is the difference between coagulative necrosis and liquifactive necrosis?

Coagulative necrosis - solid organs - proteins denature and coagulate
Liquifactive necrosis - loose tissues - proteins undergo autolysis

27

What is the difference between gangrene and necrosis?

Gangrene is necrosis visible to the naked eye

28

What is the relationship between infarction and ischaemia?

Ischaemia (restriction of blood supply) ----> infarction (death of tissue)

29

What are the two types of infarction?

Red (hemorrhagic)
White (anaemic) - after occlusion of an end artery

30

Name a molecule that leaks out from an injured cell

Myoglobin
Enzymes
Potassium

31

Under a light microscope, how does a cell undergoing apoptosis appear?

Shrunken
Eosinophilic
Chromatin condensation
Fragmentation of nucleus - karyorrhexis

32

Under an electron microscope, how does a cell undergoing apoptosis appear?

Cytoplasmic BUDDING (NOT BLEBBING)

33

________ control and mediate apoptosis

CASPASES

34

Which abnormal protein accumulates in alcoholic liver disease?

Mallory's hyaline

35

Give an example of a reason for exogenous pigment accumulation

Coal dust, tattoo

36

Give an example of a reason for endogenous pigment accumulation

Haemosiderin
Bilirubin (jaundice)

37

What are the two causes of pathological calcification?

Dystrophic
Metastatic

38

What is the difference between dystrophic and metastatic calcification?

Dystrophic - localised in one area of dying tissue, no abnormality in Ca2+ metabolism
Metastatic - body-wide/generalised, abnormality in Ca2+ metabolism

39

Give 3 consequences of cellular aging.

Accumulation of damage to DNA
Accumulation of damage to cellular components
Accumulation of abnormally folded proteins
Accumulation of lipofuscin pigment
Reduced ability to replicate

40

Give 2 effects on liver of chronic excessive alcohol intake

Fatty change
Cirrhosis
acute alcoholic hepatitis

41

Acute inflammation is a rapid response to an injurious agent that aims to do what?

Deliver mediators of host defence (leucocytes and plasma proteins) to the site of injury and so limit tissue damage, protect against infection, clear damaged tissue

42

Acute inflammation is carried out by:
a) innate immune system, or
b) adaptive immune system?

a) innate immune system

43

What is the difference between exudate and transudate?

Exudate - protein rich - develops in inflammation
Transudate - protein poor - e.g. seen in heart failure

44

Give 3 major causes of acute inflammation

Microbial infections
Acute phase hypersensitivity reactions
Physical agents
Chemicals
Tissue necrosis

45

5 cardinal signs of infection:

Rubor
Dolor
Calor
Tumor
Loss of function

46

Name the 3 tissue changes in acute inflammation:

Vascular flow
Formation of a fluid exudate
Neutrophil emigration

47

Explain the change in blood flow that occurs in acute inflammation

Arterioles vasodilate
Acceleration of flow in arterioles and capillaries
Increased capillary pressure

48

Why is an increased capillary flow important in acute inflammation?

Increased delivery of fluid and leucocytes to injured area

49

What is the main force pushing fluid out of blood vessels?

capillary hydrostatic pressure

50

What is the main force pushing fluid into blood vessels?

colloid osmotic pressure

51

In four steps, explain how vascular leakage occurs in acute inflammation.

1) Endothelial contraction ----> gaps
2) Plasma proteins leak into interstitial space
3) Upstream vessel dilates
4) Net flow of fluid out of vessels - OEDEMA

52

Why is a fluid exudate useful in acute inflammation?

Delivers plasma proteins to site of injury
Excess fluid drains in the lymphatics taking antigens + microorganisms with it, presenting them to lymph nodes

53

Neutrophils are "end cells". What are end cells?

Cannot multiply

54

Give the four steps how neutrophils get out of the vessels to kill microorganisms:

1) Margination - neutrophils line up on the edge of the vessel due to stasis
2) Rolling - Neutrophils roll along the endothelial surface
3) Adhesion - stick to the endothelium
4) Emigration
Then recognition, attachment and phagocytosis

55

Give four important chemical mediators in acute inflammation

Histamine
Bradykinin
Prostaglandin
Complement system
Cytokines and chemokines

56

What is the effect of prostaglandin?

Makes skin more sensitive to pain and causes fever

57

Which medication stops the production of prostaglandin?

NSAIDs and aspirin

58

What is the effect of histamine on the body?

Burning pain
increased vascular permeability
vasodilation

59

Which cells store histamine in the body?

Mast cells, basophils and platelets

60

How does the complement system kill bacteria?

Punches holes in bacteria
Causes inflammation also
C3b is an opsonin, aiding the phagocytosis of antigens

61

What is the function of a cytokine, such as TNF?

Messengers between cells

62

Give three local complications of acute inflammation

Damage to normal tissue
Obstruction of tubes, compression of vital structures
Loss of fluid
Pain and loss of function

63

Give three systemic complications of acute inflammation

Fever
Leucocytosis (increaased leucocytes circulating)
Acute phase response
Shock

64

Give 3 types of exudate

Pus
Hemorrhagic
Serous
Fibrinous

65

Give the type of inflammation (acute or chronic), a complication and causative organism of LOBAR PNEUMONIA

acute exudative inflammation secondary to airborne infection of the entire pulmonary lobe
by Streptococcus pneumoniae/pneumococcus
complication: lung abscess, pleural effusion, lung fibrosis

66

Name a causative organism of ascending cholangitis

E. coli

67

Name one inherited disorder of the acute inflammatory process

Hereditary angio-oedema - inherited deficiency of C1-esterase inhibitor, attacks of non-itchy cutaneous angio-oedema
Alpha-1 antitrypsin deficiency - so proteases released from neutrophils act unchecked and damage normal lung and liver tissue as they are not deactivated
Chronic granulomatous disease - phagocytes cannot generate the oxygen burst

68

What is chronic inflammation?

CHRONIC response to injury with associated fibrosis

69

What is the difference between chronic and acute inflammation?

Fibrosis
Chronic takes over acute after a few hours if the injurious agent is not removed

70

What are the dominant cells in chronic inflammation?

Macrophages
Lymphocytes

71

Give a disease where chronic inflammation occurs without any preceding acute inflammation.

TB
autoimmune diseases
toxic agents

72

Give the THREE main roles of macrophages in chronic inflammation

Phagocytosis
Produces important proteins and enzymes
Controls other cells via cytokine release
Presentation of antigens to immune system

73

What is the major difference in role between T and B lymphocytes?

T - cytotoxic functions
B - makes antibodies

74

What are macrophages called when they are circulating in the blood?

Monocytes

75

Do macrophages replicate?

Yes, unlike neutrophils!

76

Are lymphocytes usually present in tissues?

No! So their presence indicates antigenic material has been there.

77

Which cell type dominates in allergic reactions / parasitic infections?

Eosinophils

78

Which type of giant cell is characteristic of tuberculosis?

Langhan's giant cell

79

What are the three kinds of giant cells involved in chronic inflammation?

Touton - lesions with high fat content
Langhan's - TB
Foreign body

80

Give three possible complications of chronic inflammation

XS fibrosis - e.g. cirrhosis
Impaired function - e.g. Crohn's
Tissue destruction - e.g. healthy tissue taken over by fibrosis
Atrophy

81

Define the term "granuloma"

organised collection of macrophages

82

In which case would granulomatous inflammation occur?

Granuloma forms around a particle that is DIFFICULT TO DISSOLVE in an effort to destroy it.

83

What are the two types of granulomas?

Foreign body and Hypersensitivity granulomas

84

What is the difference between foreign body and hypersensitivity granulomas?

Foreign body - forms around material that is NOT antigenic
Hypersensitivity - forms around material that IS antigenic

85

Which kind of cells make up a foreign body granuloma

Lymphocytes surrounding epitheloid cells
(In TB, you also have caseous necrosis at the centre of the granuloma plus Langhan's giant cells involved too)

86

What is the role of thrombin in clot formation?

Thrombin: fibrinogen ---> fibrin (insoluable)

87

What is the name of the process by which clots are DESTROYED?

Thrombolysis

88

What are the three steps of haemostasis?

1) Severed artery contracts
2) Primary haemostatic plug of activated platelets
3) Secondary haemostatic plug of fibrin filaments (about 30 mins after initial injury)

89

Which cell produces PLATELETS?

Megakaryocytes

90

Name two platelet activators.

Collagen surfaces
ADP (released from activated platelets and injured RBCs)
Thrombin
Thromboxane

91

Once activated, what do platelets stick to?

Activated platelets stick to von Willebrand factor on the exposed subendothelium

92

In one simple statement, how does aspirin prevent clotting?

Inactivates an enzyme involved in platelet aggregation (thromboxane A2)

93

How does thrombin become activated?

Clotting factors

94

Some clotting factors require Vitamin __ for their synthesis

K

95

What is the difference between intrinsic and extrinsic pathways to blood clotting?

Intrinsic - all factors contained in blood and no vessel needs to be broken to kickstart the process
Extrinsic - needs a "tissue factor" which is not present in blood

96

Name an endothelial secretion that opposes blood clotting

tissue plasminogen activator
thrombomodulin

97

Name an endothelial secretion that favours blood clotting

Von Willibrand factor
Tissue factor

98

____ __________ helps to pull the sides of small wounds together and may toughen the clot by squeezing water out

CLOT RETRACTION

99

Name 2 plasminogen activators

Streptokinase
Urokinase
Tissue plasminogen activator

100

What is the role of plasmin?

Dissolves fibrin (fibrinolysis) and therefore thrombi and thromboemboli

101

How does the clotting cascade set fibrinolysis in motion?

Becauses fibrin increases the activity of tissue plasminogen activator which produces plasmin which causes fibrin ----> FDPs

102

Name one inherited bleeding disorder

Haemophilia A + B
Von Willebrand Disease

103

How do patients with haemophilia present?

Haemorrhage post-surgery
Easy bruising
Recurrent bleeding into joints
Petechiae

104

What kind of disease is haemophilia in terms of how it is associated with chromosomes?

X linked recessive

105

How can you diagnose haemophilia using blood coagulation tests? e.g. platelet count, bleeding time, PT, APTT

normal platelet count
normal bleeding time
normal PT (so extrinsic pathway is fine)
BUT abnormal APTT (so intrinsic pathway is affected)

106

What really is the problem in people with haemophilia?

Cannot produce enough fibrin so impaired clotting despite normal platelets

107

What is the problem in people with von Willebrand disease?

Deficient / abnormal vWF

108

How can you diagnose von Willebrand disease using blood coagulation tests? e.g. platelet count, bleeding time, PT, APTT

Raised bleeding time
raised APTT
(because platelets "stick less" to the endothelium so less platelet aggregation and hence, clotting)

109

What is the inheritance pattern of von Willebrand disease?

Autosomal dominant

110

What is thrombocytopenia?

Low platelet count

111

How does thrombocytopenia show up in blood coagulation tests?

prolonged bleeding time
normal PT + APTT (as extrinsic and intrinsic pathways are intact, the problem is the platelets!)

112

Give three causes of thrombocytopenia

Sequestration e.g. hypersplenism
Dilutional e.g. after blood transfusion
Decreased platelet survival e.g. immunological destruction, non-immunological destruction (DIC)
Decreased platelet production e.g. bone marrow infiltration by malignancy, drugs (cytotoxic)

113

Give 1 cause of thrombophilia

Protein C/S deficiency
antithrombin deficiency

114

What is disseminated intravascular coagulation?

clotting activator gets into blood and microthrombi are formed throughout the circulation, using up fibrin, platelets and coagulation factors and causing haemorrhage

115

Give three causes of DIC

sepsis
severe trauma
extensive burns
snake bites
malignancy

116

What is the treatment for DIC?

TREAT THE CAUSE

117

Give 2 ACQUIRED coagulation factor disorders

Anticoagulants e.g. warfarin
liver disease
Vitamin K deficiency

118

Regeneration (of cells) only occurs in ____ / _____ tissues (NB, not a type eg muscle, rather the general name for a group of these tissues!)

labile
stable

119

What is also known as "healing by primary intention"?

regeneration

120

What is also known as "healing by secondary intention"?

fibrous repair

121

Why does healing by fibrous repair occur in some cases instead of just regeneration?

Significant tissue loss/ if collagen or CT framework is destroyed
Ongoing chronic inflammation

122

Give an example of a labile tissue

Surface epithelia of bone marrow
Haemopoietic tissues
Columnar epithelia of GI tract and uterus

123

Give an example of a permanent tissue

Cardiac muscle cells
Skeletal muscle cells
Neurons

124

Give an example of a stable tissue

Resting lymphocytes
Bone
Parenchymal cells of liver, kidneys, pancreas

125

What is the difference between labile, stable and permanent tissues?

Labile - continuously dividing tissues as cells are short lived
Stable - rapid division in response to stimuli, quiescent
Permanent - non-dividing tissues

126

Stem cells undergo assymetric replication. What does this mean?

When the stem cell divides, it produces a stem cell like itself and a differentiated cell

127

Give 2 places where stem cells can be found in the body

Liver, between hepatocytes and bile ducts
Epidermis, in basal layer
Intestinal mucosa, at bottom of crypts

128

What is the difference between totipotent, multipotent and unipotent stem cells?

Unipotent - produces one type of differentiated cell
Totipotent - produces ANY type of differentiated cell (this is an embryonic stem cell)
Multipotent - produces several types of differentiated cell

129

Give an example of a multipotent stem cell

Haemopoietic stem cell of the bone marrow

130

Which three cell types are involved in fibrous repair?

Inflammatory cells like neutrophils, macrophages which phagocytose the debris
Endothelial cells (angiogenesis)
Fibroblasts and myofibroblasts

131

What are the four steps of the fibrous repair process?

Phagocytosis... of necrotic tissue debris
Proliferation... of epithelial cells - angiogenesis
Proliferation... of fibroblasts and myofibroblasts which synthesise collagen and cause wound contraction
Fibrous scar.... forms then matures and shrinks (myofibroblasts)

132

Enzymatic modification of the polypeptide alpha chain in collagen synthesis involves hydroxylation which requires Vitamin ___.

vitamin C

133

In collagen synthesis, procollagen is cleaved to produce _______ which goes on to polymerize, forming fibrils.

TROPOCOLLAGEN

134

At the last step of collagen synthesis, cross linkage of collagen fibres increases ____ ______

tensile strength

135

Name an acquired condition that results in defective collagen synthesis?

Scurvy

136

In which cellular component does the intracellular part of collagen synthesis occur?

Endoplasmic reticulum

137

Name three inherited conditions which result in defective collagen synthesis.

Osteogenesis imperfecta
Ehlers-Danlos Syndrome
Alport syndrome

138

What are 3 characteristic features of Ehlers-Danlos syndrome?

Hyperextensible skin, fragile skin, hypermobile joints, poor wound healing

139

What are 2 characteristic features of Alport syndrome?

Dysfunction of glomerular basement membrane, cochlea of ear and lens of eye
Haematuria in children
Renal failure

140

What are three elements that granulation tissue consists of?

developing capillaries
myofibroblasts and fibroblasts
chronic inflammatory cells

141

What is a growth factor?

Polypeptides that act on cell surface receptors
Stimulate transcription of genes that regulate entry of cell into the cell cycle

142

Name the three ways to describe cell to cell signalling:
1) endocrine... to a distant cell, via blood stream
2)
3)

paracrine - to a nearby cell
autocrine - to itself

143

Name two types of cells that produce growth factors

Endothelial cells
Platelets
Macrophages

144

What is the similarity between cadhesins and integrins?

Both are adhesion molecules

145

What is the difference between cadhesins and integrins?

Cadhesins bind cells to each other and integrins bind cells to extracellular matrix

146

What are the five steps in healing of bone fractures?

1) Haematoma
2) Granulation tissue
3) Soft callus
4) Hard callus
5) Lamellar bone

147

Name five local factors that affect growth and repair

blood supply
denervation
infection
foreign bodies
necrotic tissue
surgical techniques
mechanical stress

148

Name four systemic factors that affect growth and repair

Diabetes
Age
Obesity (more tension on wound)
Genetic disorders e.g. Ehlers-Danlos
Malnutrition
Vitamin deficiency
Drugs e.g. steroids inhibit collagen synthesis

149

Why does taking steroids make healing time longer?

Steroids inhibit collagen synthesis

150

Why do diabetic patients have prolonged healing time?

decreased resistance to infection
microangiopathy means decreased blood to site

151

Give three complications of fibrous repair

Formation of fibrous adhesions
Dusruption of normal organ architecture
Loss of function (replacement of specialised tissue with scar tissue)
OVERPRODUCTION of scar tissue e.g. keloid scar
Insufficient fibrosis
Excessive scar contraction e.g. fixed flexures

152

What is a keloid scar?

Overgrowth of fibrous tissue that exceeds borders of the scar and does not regress - common in Afro-Caribbean population

153

Why does cartilage not heal well?

No blood supply
No innervation
No lymphatic drainage

154

When a peripheral nerve is severed, it can regenerate, elongating slowly guided by _______ cells

Schwann cells

155

What is an atheroma?

Accumulation of Fatty deposits found on the inside of artery walls
The gruel-like necrotic material present in atherosclerotic plaques

156

What is atherosclerosis?

Thickening and hardening of arterial walls due to buildup of fatty plaques and hypertension/diabetes (which damages the walls)

157

What is the difference between atherosclerosis and arteriosclerosis?

Atherosclerosis - artery walls only
Arteriosclerosis - artery and arteriole walls affected

158

What are the five steps leading to formation of atherosclerotic lesions?

1) chronic endothelial injury
2) monocyte accumulation, growth factors released, cytokines released, platelet adhesion
3) smooth muscle emigration from media to lamina
4) macrophages and smooth muscle cells engulf lipid to form foam cells
5) proliferation of smooth muscle cells, collagen and matrix deposition, extracellular lipid deposition, neovascularisation

159

What is a foam cell?

Macrophage/smooth muscle cells engulf lipid to form foam cells

160

How does a fatty streak evolve in atherosclerosis?

Fatty streak ---> Simple plaque ---> Complicated plaque

161

How does a fatty streak appear on a macroscopic level?

Yellow and slightly raised, lipid deposits in intima

162

What is the difference between the macroscopic appearance of simple and complicated plaques on arterial walls?

Simple - (irregular outline), widely distributed and raised; yellow or white
Complicated - haemorrhage into plaque and calcification

163

State two early microscopic changes in atherosclerosis

Accumulation of foam cells
proliferation of smooth muscle cells
extracellular lipid deposition

164

Name three later microscopic changes in atherosclerosis

Fibrosis
Necrosis
Ingrowth of blood vessels
disruption of internal elastic lamina

165

What are three of the most common sites for atherosclerosis

Aorta
coronary arteries
carotid arteries
cerebral arteries
leg arteries

166

What are three ways to prevent atherosclerosis?

no smoking
reduce fat intake
treat hypertension
reduce alcohol intake
regular exercise

167

What are three ways to intervene in a patient with atherosclerosis?

Lipid lowering drugs
treat diabetes
treat hypertension
stop smoking
modify diet

168

Give three effects of severe atherosclerosis?

Abdominal aortic aneurism
ischaemic heart disease - MI, angina pectoris, arrhythmia
cerebral ischaemia - cerebral infarction (stroke), transient iscaemic attacks
peripheral vascular disease - gangrene, ischaemic rest pain

169

Give 6 risk factors of atherosclerosis

Diabetes mellitus
smoking - increases platelet aggregation
hypertension - damages endothelium due to raised pressure
age
gender
alcohol intake
hyperlipidemia
geography
infection - H. pylori, Cytomegalovirus

170

Why do smokers have an increased risk of atherosclerosis?

Increased platelet aggregation

171

Which 6 types of cells are involved in atherosclerosis?

endothelial cells
platelets
smooth muscle cells
macrophages
lymphocytes
neutrophils

172

What is a "thrombus"?

solid mass formed from the constituents of blood within the heart or vessels during life

173

Thrombosis occurs when three changes occur... these three changes collectively are known as ___________________

Virchow's triad

174

What are the three changes that occur which result in thrombosis?

Changes in vascular wall (endothelial damage)
Changes in blood flow (slow or turbulent flow)
Changes in the blood (hypercoagulability)

175

Why is there an increased risk of thrombi in the lower limbs in pregnancy?

Because two of the three factors of Virchow's triad occur - hypercoagulability and stasis (due to pressure on the large veins in the pelvis by the uterus)

176

Give three cases in which there is endothelial damage, which may result in thrombosis.

following an MI
secondary to hypertension
scarred heart valves
after trauma or surgery
in inflammation
on the surface of atherosclerotic plaques when they break open

177

In clotting when there is endothelial damage, to what do platelets adhere?

Exposed Von Willibrand factor

178

Imagine there is endothelial damage but blood flow is fast as usual. Why will this not result in a thrombus?

Because current washes away platelets, clotting factors and chemical mediators and the thrombi can't grow.

179

Why is blood hypercoagulable in pregnancy, after surgery, fractures or burns?

Increased levels of fibrinogen and factor VIII

180

Why are platelets concentrated along the endothelium?

Because they are the smallest formed elements in the blood

181

Describe the process of the formation of a thrombus

Platelets aggregate
Firbinogen binds platelets together
Fibrin grows out of the platelet layer
Fibrin traps RBCs (so white layer of platelets is covered by a red layer of RBCs and fibrin)
Surface of red layer is thrombogenic so platelets stick to exposed fibrin
Process continues

182

What are "lines of Zahn"?

Laminations in the thrombus that are visible to the naked eye (because in a thrombus there are layers of white platelets and red blood cells/fibrin)

183

What is "thrombophlebitis"?

Painful superficial thrombi (in superficial veins) which have associated inflammation in the wall of the vein

184

What is the difference between parietal and occlusive thrombi?

Parietal - attached to the wall of vessel and restrict the vessel partially
Occlusive - completely obstruct the lumen

185

What is the specific name for a thrombus found on a cardiac valve?

Vegetation

186

What are four possible outcomes of a thrombus?

Resolution - dissoved
Propagation - grows
Organisation - fibrous repair and forms a fibrous scar
Recanalisation - new channels lined with endothelium run through the occlusion and restore blood flow
Embolisation - part of the thrombus breaks off and embolises

187

What are two most common clinical effects of thrombosis?

1) occlusion of an artery ---> ischaemia and infarction
2) embolisation resulting in artery occlusion distant to the site of the thrombus
3) congestion and oedema in the venous bed and associated pain
4) repeated miscarriages

188

What is an embolism?

Sudden blocking of an artery by a foreign material brought to its current position via the blood current (embolus)

189

What is an embolus?

Solid, liquid or gas that is carried by the blood and is large enough to become impacted in a vascular lumen

190

What is a thromboemboli and what is the difference between it and just an emboli?

Thromboemboli are derived from thrombi, whereas an embolus could be any solid, liquid or gas that has become impacted in a lumen, which includes thromboemboli but many others as well e.g. fat emboli....

191

What are 5 things an emboli can be composed of, besides platelets and fibrin?

Fat
Bone marrow
Material from atheromatous plaques
Tumour fragments
Parasites
debris inserted IV
amniotic fluid
medical equipment
bits of brain or liver after trauma

192

Can embolization occur in veins? Why?

No. Blood flow is from smaller to larger vessels

193

What happens to thrombi formed in veins?

They do not embolise in veins, as venous system is from smaller to larger vessels. They go to the right heart and then embolise in pulmonary arteries

194

Where do emboli from the left heart or aorta end up?

Anywhere in the systemic circulation especially in lower limbs.

195

Approximately 80% of pulmonary emboli arise from thrombi in the _____________________ and ________________

deep veins of the thigh and popliteal vein

196

Large emboli that become lodged astride the bifurcation of an artery blocking both branches are called ______________

saddle emboli

197

Give three reasons why thrombi are often seen in the left heart.

1) Infarcts commonly form on the left ventricle, damaged endothelium encourages thrombi formation and because heart is beating, these thrombi often embolise
2) atrial fibrillation causes decreased atrial contraction, dilation of the left atrium, stagnation of blood and thrombus formation
3) vegetations are more common on the valves of the left heart

198

What is a "paradoxical emboli"?

Embolisms that form in the systemic veins embolise to the systemic arteries. They bypass the lungs because of an atrial septal defect or an interventricular septum defect OR the arterio-venous anastomoses in the pulmonary circulation when the pressure in the venule is higher than the pressure in the arteriole.

199

When a young person has an ischaemic stroke, which heart defect might he have?

Patent foramen ovale
Because the patient probably had a paradoxical embolus that caused the stroke
Which is an embolus that goes from the systemic veins to the systemic arteries
Usually occurs due to ASD/VSD

200

What are transient ischaemic attacks?

Episodes of neurological dysfunction that appear suddenly, last minutes to hours and then disappear. They are the result of microscopic emboli to the brain.

201

Transient ischaemic attacks usually happen as the result of which 2 kinds of embolism originating from where?

Atheroemboli from carotid arteries
Thromboemboli from the left heart

202

Why do transient ischaemic attacks not have lasting effects?

Because the emboli are so small that they break up quickly before any damage can be done

203

Fat emboli can occur after __________

liposuction

204

Bone marrow emboli can occur after ________

bone fractures

205

Scuba divers may experience "the bends" if they resurface too quickly. Why is that?

Under the water, outside pressures are higher than that on land so increased amounts of gas become dissolved in the blood and body tissues. If scuba divers resurface too quickly, then the sudden drop in pressure causes gases to come out of solution and into the body tissues as bubbles (air embolism), causing a huge amount of pain and blocking blood flow.

206

What are the two things that general prophyaxis of thromboembolic diseases aims to prevent?

Preventing venous stasis
Preventing hypercoagulability

207

What are the measures used to prevent venous stasis and hence prevent thromboembolic disease?

encourage patients to mobilize early after an operation or illness
elevating legs after an operation
compression stockings
calf muscle stimulation

208

What measure is used to prevent hypercoagulability and hence prevent thromboembolic disease?

Anticoagulants - aspirin, heparin and warfarin

209

Name the three anticoagulants that are used to prevent hypercoagulability and hence prevent thromboembolic disease?

aspirin, heparin and warfarin

210

Warfarin is used as prophylaxis against thrombosis. it is an oral medication which interferes with ____________ metabolism

Vitamin K

211

What is an "infection"?

The introduction of a microorganism into a normally sterile tissue

212

Differentiate between septicaemia and sepsis

Septicaemia is the presence of a pathogen in the blood which can lead to sepsis

213

What is the difference between sepsis and severe inflammatory response syndrome (SIRS)?

SIRS is a group of classical clinical signs in response to inflammation. SIRS can be as a result of infection but also as a result of surgery, malignancy, trauma... Sepsis is two or more of these signs but specifically in response to infection.

214

When does sepsis become severe sepsis?

When there is at least one sign of organ dysfunction (due to organ hypo-perfusion)

215

What three things determine the size of a cell population? (Hint: all three are RATES...)

Rate of cell proliferation
Rate of cell death by apoptosis
Rate of cell differentiation

216

_________ regulate normal cell proliferation

PROTO ONCOGENES

217

What are the four stages of the cell cycle?

M - mitosis - cell divides
G1
S - DNA synthesis
G2

218

What is the R point (restriction point) in the cell cycle?

most critical checkpoint as the majority of cells that pass the R point will also complete the cell cycle. This is the most commonly altered checkpoint in cancer cells!

219

What are two proteins that regulate and control the cell cycle?

Cyclins
Cyclin-dependent kinases

220

How do cyclins and cyclin-dependent kinases work to control the cell cycle?

When cyclin binds to CDK, it activates the CDK which then can go on to phosphorylate proteins

221

What is cell adaptation?

Response by cells to challenges that are not severe enough to cause injury by adaptations that are not pathologic

222

What are the five ways by which cells can adapt to challenges that are not severe enough to cause injury?

regeneration
atrophy
hypertrophy
metaplasia
hyperplasia

223

Cell adaptation: What is "regeneration"?

cells multiply to replaces losses. This can be normal (e.g. replacement of RBCs and WBCs by the bone marrow) or can also be after injury.

224

What two tissues are incapable of regeneration?

Adipocytes
Neurones of the CNS

225

Cell adaptation: What is atrophy?

Cells become smaller

226

Cell adaptation: What is hypertrophy?

Cells increase in size

227

Cell adaptation: What is metaplasia?

Cells are placed by a different kind of cell

228

Cell adaptation: What is hyperplasia?

Cells increase in number above normal

229

What is an example of normal atrophy of cells in a tissue?

Ovarian atrophy - after menopause
Uterine atrophy - after pregnancy

230

What are 2 examples of why pathological atrophy of cells in a tissue may occur?

atrophy of disuse - muscle atrophy
denervation atrophy
inadequate blood supply leading to atrophy

231

Give 2 examples of pathological atrophy of cells in a tissue

senile atrophy
loss of endocrine stimuli
pressure (e.g. due to a tumour)
thenar atrophy
cerebral atrophy (Alzheimers)
osteoporosis

232

Hypertrophy is the type of cell adaptation that occurs mainly in which kind of tissue (e.g. labile, stable or permanent)?

Permanent tissue

233

Give an example of non-pathological hypertrophy

Hypertrophy of skeletal muscle cells in body builders

234

Give an example of pathological hypertrophy

Compensatory hypertrophy e.g. of one kidney
OR RV hypertrophy

235

Give an example of metaplasia and state which cell types are being replaced with what.

Barrett's oesophagus (stratified squamous epithelium to gastric glandular epithelium)
Smoker's lung (bronchial pseudostratified ciliated epithelium to stratified squamous epithelium)

236

Give an example of pathological and non-pathological hyperplasia.

Pathological - eczema - hyperplasia of epidermis
Non-pathological - proliferative endometrium - under influence of oestrogen

237

What is "aplasia"?

complete failure of a tissue or organ to develop or an organ whose cells ceased to proliferate

238

What is "dysplasia"?

abnormal maturation of cells within a tissue

239

What is "involution"?

normal programmed shrinkage of an organ e.g. thymus in early life, uterus after childbirth

240

What is "hypoplasia"?

congenital underdevelopment or incomplete development of a tissue or organ e.g. testicules in Klinefelter's

241

People with Klinefelter's have which sex chromosomes?

XXY

242

What is "atresia"?

no orifice, congenital imporforation of an opening e.g. anus/vagina

243

Define "neoplasm"

an abnormal growth of cells that persists after the initial stimulus is removed

244

What is the similarity and difference between neoplasia and hyperplasia?

SIMILARITY - both cause an increase in the number of cells above normal
DIFFERENCE - hyperplasia is stimulated by growth factors and is reversible whereas neoplasia is caused by genetic alterations and is irreversible

245

What is a "malignant neoplasia"?

An abnormal growth of cells that persists after the initial stimulus is removed AND it invades surrounding tissue with the potential to spread to different sites

246

What is the difference between benign and malignant neoplasms?

Benign - remain confined to their site of origin, do not produce metastases
Malignant - does not remain confined to the site of origin, potential to metastasise

247

Is neoplasm = cancer?

NO! Cancer is a malignant neoplasm.

248

What is the difference between tumour and neoplasm?

Tumour is any clinically detectable lump or swelling. Neoplasm is only one type of tumour. e.g. it could just be a fluid-filled bursa OR a fibroid

249

What is a "metastasis"?

Malignant neoplasm that has spread from its original site to a new, non-contiguous site

250

How do malignant tumours appear to the naked eye?

irregular outer margin
irregular shape
may show areas of necrosis and ulceration if on a surface

251

How do benign tumours appear to the naked eye?

confined local area
pushing outer margin

252

What are cells with no resemblance to any tissue called?

ANAPLASTIC

253

What do cells of a benign neoplasm look like under a microscope?

Well differentiated
resemble the parent tissue

254

What do cells of a malignant neoplasm look like under a microscope?

Range from well to poorly differentiated
With worsening differentiation, there is:
increasing nuclear size and nuclear to cytoplasmic ratio
increasing mitotic figures
increasing variation in size and shape of cells and nuclei
increasing nuclear staining

255

What is pleomorphism, in relation to cells of a malignant neoplasm?

Increasing variation in size and shapes of cells and nuclei

256

Clinicians use the term _______ to indicate differentiation

GRADE

257

A neoplasm emerges from a monoclonal population of mutant cells through a process called _______, which is the accumulation of yet more mutations

progression

258

How does an expanded, monoclonal population of mutant cells come about from normal cells?

Initiators (mutagenic agents) + promoters (which cause cell proliferation)

259

What does it mean if a collection of cells is referred to as "monoclonal"?

They all originated from a single founding cell

260

What two genes do genetic alterations that lead to cancer usually affect?

Proto-oncogenes
Tumour suppressor genes

261

When proto-oncogenes are abnorally activated, what are they then called?

Oncogenes

262

Benign neoplasms usually have what suffix?

-oma

263

Malignant neoplasms usually have what suffix?

-carcinoma (if epithelial malignant) OR
-sarcoma (if stromal malignant)

264

What is an "adenoma"?

Benign neoplasm of glandular epithelium

265

What is the difference between an in-situ and an invasive carcinoma?

In-situ - no invasion through epithelial basement membrane
Invasive - penetrates through epithelial basement membrane

266

What is "leukemia"?

Malignant neoplasm of blood-forming cells arising in the bone marrow

267

What is "lymphoma"?

Malignant neoplasm of lymphocytes, mainly affecting lymph nodes

268

What is a "myeloma"?

Malignant neoplasm of plasma cells

269

In the ovary, what kind of germ cell neoplasm arises from pluripotent cells?

Benign teratoma

270

In the testes, what kind of germ cell neoplasm arrives from pleuripotent cells?

Malignant teratoma
seminoma

271

Invasion into surrounding tissue by carcinoma cells involves 3 important alterations:

Motility - changes in actin skeleton
Adhesion - altered adhesion between malignant cells and stromal proteins which involves changes in integrin proteins
Stromal proteolysis - cells degrade basement membrane and stroma which involves altered expression of proteases
^ "MASs" like a tumour

272

Carcinoma cells look more like ________ cells than epithelial cells

mesenchymal

273

Transport of carcinoma cells to distant sites is via 3 routes. Name these 3 routes.

1) Blood vessels
2) lymphatic vessels
3) fluid in body cavities (pleura, pericardial, peritoneal)

274

Surviving microscopic deposits of malignant cells that fail to grow are called ___________

micrometastases

275

What is tumour dormancy?

When a seemingly disease-free person harbours many micrometastases

276

What three factors could cause someone with tumour dormancy to suddenly have their micrometastases to start growing?

Immune attack
Angiogenesis
Hostile secondary site

277

Which two factors determine the site of a secondary tumour?

1) regional drainage of blood, lymph and coelomic fluid
2) the "seed and soil" phenomenon - interaction of the malignant cells with their local tumour environment

278

Give three examples of local effects of primary and secondary neoplasms

direct invasion and destruction of normal tissue
ulceration at a surface leading to bleeding
compression of adjacent structures
blocking tubes and orifices

279

Give 5 examples of the systemic effects of neoplasms

reduced appetite and weight loss (cachexia)
malaise
immunosuppression
thrombosis
may produce hormones (e.g. thyroid adenoma produces thyroxine)
skin problems such as pruritis and abnormal pigmentation
fever
finger clubbing
myositis

280

Give 3 behavioural and dietary risk factors related to cancer

High body mass index
Low fruit and vegetable intake
Lack of physical activity
Tobacco use
Alcohol use

281

Extrinsic carcinogens fall into 3 main categories:

chemicals
radiation
infections

282

There are 6 classes of mutagenic chemical carcinogens. Name 3 of these classes.

Polycyclic aromatic hydrocarbons
Aromatic amines
N-nitroso compounds
Alkylating agents
Diverse natural products e.g. asbestos

283

Procarcinogens are only converted into carcinogens by the ___________________________ enzymes in the liver

cytochrome P450

284

What are "complete carcinogens"?

Carcinogens that act as both initiators + promoters

285

Give an example of a "complete carcinogen"

cigarette smoke

286

Radiation can affect DNA directly but also indirectly by generating ____ ________

free radicals

287

_________ radiation damages DNA bases and causes single and double strand DNA breaks

Ionising
e.g. X rays and nuclear radiation

288

How can some infections be direct carcinogens?

They directly affect the genes that control cell growth

289

Human Papilloma virus which is strongly linked to ______ carcinoma is a direct carcinogen because it expresses the E6 and E7 proteins that inhibit ___ and ____ proteins both of which are important in cell proliferation.

Human Papilloma virus which is strongly linked to cervical carcinoma is a direct carcinogen because it expresses the E6 and E7 proteins that inhibit p53 and pRB proteins both of which are important in cell proliferation.

290

How does HIV act indirectly as a carcinogen?

Lowers immunity, allowing other potentially carcinogenic infections to occur

291

Inherited predisposition to neoplasia can occur through germline mutations. Retinoblastoma has what pattern of inheritence?

Dominant

292

The ___________ hypothesis explains why people who are predisposed to certain types of cancer do not always end up acquiring them in their lifetimes.

two hit hypothesis

293

Two hit hypothesis: For familial cancers, the first "hit" is delivered through the germline and affected all cells in the body. The second hit was a ______________________

somatic mutation

294

Genes that inhibit neoplastic growth are known as _____ __________ _____

tumour suppressor genes

295

Why are two hits needed in order to inactivate the tumour suppressor genes?

Both alleles need to be mutated and inactivated

296

Genes that enhance neoplastic growth are known as _______

oncogenes

297

Are two hits needed in order to activate the oncogenes and hence favour neoplastic growth?

No. Only one hit necessary, one allele activated is enough to enhance neoplastic growth.

298

Give four things that proto-oncogenes can encode.

Growth factors
Growth factor receptors
Plasma membrane signal transducer
Intercellular kinases
Transcription factors
Cell cycle regulator
Apoptosis regulator

299

____________ ____________ is a condition that is due to mutations in one of the 7 genes that affect DNA nucleotide excision repair. Patients with this condition are very sensitive to UV damage and develop skin cancer at a young age.

Xeroderma pigmentosum

300

What is the inheritence pattern of xeroderma pigmentosum?

Autosomal recessive

301

Heriditary non-polyposis colon cancer syndrome is associated with _______ carcinoma

colon

302

Heriditary non-polyposis colon cancer syndrome is autosomal dominant and the germline mutation affects what type of gene?

DNA mismatch repair genes

303

Familial breast carcinoma is associated with which two genes that are important for repairing double strand DNA breaks?

BRCA1 and BRCA2

304

BRCA1 and BRCA2 are two genes associated with familial breast carcinoma. What is the role of these two genes?

Double strand DNA break repair

305

A fully evolved malignant neoplasm exhibits six hallmarks of cancer.
Name four of these hallmarks.

1) self-sufficient growth signals
2) resistant to growth stop signals
3) no limit to the number of times the cell can divide
4) sustained ability to induce new blood vessels
5) resistance to apoptosis
6) the ability to invade and produce metastases ---> only malignant

306

Name three of the most common carcinomas in the UK

bowel
prostate
lung
breast

307

In children younger than 14, what are two of the most common cancers?

leukaemias
CNS tumours
lymphomas

308

What is "tumour stage" the measure of?

the malignant neoplasm's overall burden

309

What is the name of the commonest method for assessing the extent of a tumour?

TNM staging system

310

In the TNM staging system for staging tumours, what do T, N and M stand for?

T - size of the primary tumour - T1 to T4
N - extent of regional node metastasis / lymphatic spread - N0 to N3
M - extent of distant metastatic spread / spread via blood stream - M0 or M1

311

Lymphoma has its own staging system. What is the name of this staging system?

Ann Arbor staging

312

What is the name of the staging system for colorectal carcinoma?

Dukes staging

313

What does tumour grade describe?

the degree of differentiation of a neoplasm

314

When talking about the grade of a malignant neoplasm, what do G1 and G4 say about the differentiation of the cells of the tumour?

G1 - well-differentiated
G4 - undifferentiated or anaplastic

315

What is the name of the grading system for breast cancer?

Bloom-Richardson system

316

Why is grading a tumour important?

Planning treatment
Estimating prognosis

317

What is the difference between adjuvant and neoadjuvant treatment for a cancer?

Adjuvant - given after surgical removal of a primary tumour
Neoadjuvant - given to reduce the size of a primary tumour prior to surgical excision

318

How does radiation therapy kill proliferating cells?

Triggers apoptosis OR interferes with mitosis
Targets rapidly dividing cells

319

Several classes of chemotherapy exist. Name all 4 of these classes

antimetabolistes
alkylating and platinum based drugs
antibiotics
plant-derived drugs

320

What is the ONE MAIN difference between chemotherapy and radiotherapy?

chemotherapy is non-specific and radiotherapy is specific (only targets cancer cells)

321

Give an example of a drug that is used in hormone therapy for breast cancer patients.

Tamoxifen

322

How does tamoxifen work to treat malignant breast cancer?

Tamoxifen is a selective oestrogen receptor modulator
It binds to oestrogen receptors
Oestrogen cannot bind to the receptors
So breast cancers don't grow

323

_______ _________ are used to monitor cancer burden during treatment and follow up.

Tumour markers

324

What are 2 types of tumour markers used to monitor cancer burden during treatment and follow up?

hormones
oncofetal antigens
specific proteins
mucins/glycoproteins

325

What three kinds of cancers are screened for in the UK?

breast cancer
bowel cancer
cervical cancer

326

Give two advantages for performing cytology rather than a biopsy for histology?

Cheap
Minimally invasive
Quicker
Relatively safe

327

Give 2 reasons why a person would be required to have a coroner's autopsy

suspicious death
unnatural death
if the deceased is unknown
if the deceased died in custody
if the deceased was not seen by a doctor within 14 days of death
if the death was a result of a termination of a pregnancy
if the death was a result of an accident

328

What substance if present in the blood would confirm the presence of a myocardial infarction?

Troponin I or troponin T

329

Why does troponin get into the blood stream after a myocardial infarction?

Area of cardiac muscle has undergone necrosis due to the lack of blood supply
In necrosis, cell membrane would become leaky and intracellular proteins leak out of cells and can be measured in the blood

330

Name three conditions in which fatty liver is commonly seen

Excessive alcohol intake
Obesity
Diabetes mellitus
Carbon tetrachloride toxicity

331

Which two substances accumulate in hepatocytes of patients who drink XS alcohol?

Fat
Mallory's hyaline

332

How does cirrhosis appear histologically?

Bands of fibrosis
Surrounding nodules of regenerating hepatocytes

333

Give 3 examples of opsonins

CRP
C3b
C4b
IgG
IgM
collectins

334

Give one example of how the body protects itself against free radicals

Antioxidants like vitamins A, C and E donate an electron to a free radical thus neutralising it

335

What is a "free radical"?

Reactive oxygen species / Molecules with a single unpaired electron in the outer orbit

336

What is "chemotaxis"?

Directional movement towards or away from a chemical attractant

337

What is "diapedesis", which is used by neutrophils in acute inflammation?

passage of blood cells through intact blood vessel walls

338

Give an example of a chemoattractant.

fibrin degradation product
endotoxin
thrombin

339

How is an ulcer in the GI tract defined?

Breach in the lining of the bowel to the level of the submucosa or deeper

340

What are the two classical histological features of Crohn's disease?

Transmural inflammation
Presence of granulomas

341

Give two features seen at colonoscopy that are typical of Crohn's disease.

discontinuous distribution
cobblestone appearance to bowel mucosa
strictures
fistulas
rectal sparing
involvement of the ileum

342

What's the difference between ulcerative colitis and Crohn's disease?

Ulcerative colitis affects only the mucosal layer of the large intestine. It is continuous inflammation.
In Crohn's disease, inflammation can appear anywhere in the digestive tract, from the mouth to the anus. And it generally affects all the layers of the bowel walls, not just the inner lining. It can appear as patches of inflammation unlike UC.

343

People with ulcerative colitis and Crohn's disease often develop red marks just below the skin surface, particularly on their shins. What is this condition called?

Erythema nodosum

344

What are abdominal adhesions?

Bands of fibrous tissue that form between abdominal tissues and organs

345

A 21 year old woman is admitted to hospital after having taken 25g of paracetamol 2 days earlier. Why is her alanine aminotransferase high?

Hepatocytes died as a result of paracetamol toxicity and ALT leaked out of the damaged cell membranes of these cells

346

Which drug raises the PT and is monitored by regular INR measurements?

Warfarin

347

Give three conditions for which warfarin would be prescribed?

Atrial fibrillation
DVT
pulmonary embolism
following heart valve replacement