Pathology Flashcards
1
Q
What are the 3 types of growth receptor?
A
tyrosine kinase receptors; GPCRs and receptors without tyrosine kinase activity
2
Q
What are the main stages of the cell cycle?
A
G1, S, G2 and M
3
Q
What controls the steps of the cell cycle?
A
cyclin dependent kinases that activate each other and other enzymes
4
Q
What is the main cyclin expressed during metaphase?
A
cyclin B
5
Q
What happens in G1?
A
cell gets bigger with increased protein synthesis
6
Q
What CDK is actiavted during G1?
A
CDK4
7
Q
What is the effect of CDK4?
A
phosphorylates the retinoblastoma protein
8
Q
What cyclin activates CDK4?
A
cyclin D
9
Q
What is the retinoblastoma protein usually bound to?
A
E2F
10
Q
What is the function of E2F?
A
stimulates cell division
11
Q
What is the function of the phosphorylation of Rb?
A
Rb can’t bind to E2F so E2F is able to stimulate cell disivion
12
Q
What cyclin does E2F increase the levels of?
A
cyclin A
13
Q
What CDK does cyclin A actiavte?
A
CDK2
14
Q
What is the function of CDK2?
A
promotes DNA replication
15
Q
What should be present at the end of S phase in the cell?
A
2 copies of genome
16
Q
What is the main chekcpoint protein at the end of G2?
A
p53
17
Q
What is the function of p53?
A
checks for DNA mistakes
18
Q
Give an example of a cell which is terminally differentiated (can’t divide) or exhibit replicative sensence?
A
neurons
19
Q
What is the function of telomeres?
A
provides protection and stops chromosome ends from degradation and fusion
20
Q
Where does hypertrophy occur in isolation without hyperplasia?
A
in non-dividing cells eg cardiac myocytes and SK muscle
21
Q
Which hormones promote degradation and atrophy?
A
glucocorticoids and thyroid hormone
22
Q
What pathway are proteins often degraded by?
A
ubiquitin proteasome pathway
23
Q
What is vasodilation in inflammation mediated by?
A
histamine and nitric oxide
24
Q
What allows white cell margination?
A
vascular dilatation which slows rate of flow
25
What do selectins bind to?
proteoglycans on white cellls
26
Where are integrins found?
surface of white cells
27
what do integrins bind to?
ICAM
28
What factors increase selectin expression?
histamine and thrombin
29
What factors increase cell expression of VCAM and ICAM?
TNF and IL1
30
What is the function of chemokines on the endothelial cell surface?
bind to proteoglycans to increase the affinity of VCAMs and ICAMs for integrins
31
What substances cause endothelial contraction?
histamine; bradykinin; substance P; leukotrienes
32
What mediates transcytosis?
VEGF
33
What is chemotaxis?
cells follow a chemical gradient
34
What is pain in inflammation mediated by?
prostaglandins and bradykinin
35
What is resolution?
complete restoration of the itssue to nomral after removal of inflammatory components
36
What is required for resolution?
tissue capacity for repair; good vascular supply; scaffold
37
What healing is favoured if damage goes beyond the basemenet membrane?
organisation and repair
38
What happens after granulation tissue?
defect is slowly infiltrated by capillaries and then myofibroblasts which deposit collagen and SM
39
When is chronic inflammation favoured?
suppuration; persistence of injury and types of injury e.g autoimmune
40
Waht is chronic inflammation characterisedby?
lymphocytes and macrophages
41
What are the outcomes of acute inflammation?
resolution; suppuration; repair organisation and fibrosis; chornci inflammation
42
What does increased calcium in the cell stimulate?
ATPase; phospholipase; proteases; endonucleases; mitochondrial permeability
43
What is pyknosis?
irreversible condensation of chromatin in a cell undergoing necrosis or apoptosis
44
What are the first signs of necrosis?
cells shrink; become red; darkened nucleus and marginal contraction bands appear
45
What is diapedesis?
passage of blood cells thorugh endothelium
46
What are hte types of necrosis?
caseous; liquefactice; coagulative
47
What is seen with coagulative necrosis?
cell death with some structure of cells left as ghost outline before complete phagocytosis
48
When is the greatest risk of cardiac rupture following an MI?
3-7 days
49
What colour does the presence of macrophages cause?
yellow
50
What happens in restitution?
macrophages are replaced by fibroblasts
51
What is the difference between neoplasia and hyperplasia?
neoplasia is new growth not in response to a stimulus
52
What is the only part of the body not to undergo neoplasia?
lens of the eye
53
What is metaplasia?
reversible change from one mature cell to another mature cell type
54
What causes metaplasia?
change in signals delivered to stem cells causing them to differentiate down a different line
55
Why is squamous metaplasia commonly encountered in response to injury?
very resistant to noxious stimuli
56
What is dysplasia?
disordered growth
57
What are Weinberg hallmarks?
specific genes/proteins with specific functions that enable cellular progression to malignancy
58
What is the affected gene in FAP?
APC
59
What is the double hit hypothesis?
need two faulty copies to have a functional problem
60
What disease is associated with p53 mutation?
Li Fraumeni syndrome
61
What mutation is associated iwth MEN1?
RET
62
What mutations are associated with aflatoxins?
p53
63
What problem does radiation cause?
formation of pyrimidine dimers in DNA
64
What is the defect in xeroderma pigmentosa?
defect in nucleotide excision repair
65
What virus is E7 associated with?
HPV
66
What does E7 do?
binds to retinoblastoma which results in free E2F
67
What is the function of E6?
increases destruction of p53
68
Waht type of UV radiation is really bad?
UVB
69
What are the effects of vitamin D on the skin?
increase cell differentiation and apoptosis and decrease angiogenesis
70
What type of cancer is especially asssocaited iwth RAS mutations?
pacnreas
71
What cancer is assocaited with Braf mutations?
melanomas
72
What cancer is associated with C-KIT?
GI stromal tumours
73
What is Myc?
a nuclear transcription factor that promotes growth
74
What is the most commonly mutated kinase in cancer?
PI3K
75
How does p53 pause the cell cycle?
increases levels of p21 which inihibts CDK
76
How does p53 induce apoptosis?
via BAX pathway
77
What is the fucntion of Bcl-2?
binds bax/Bak to stop holes being punched in mitochondria- anti-apoptotic molecule
78
What is the function of MLH1?
mismatch repair protein
79
What syndrome has an abnormal MLH1?
lynch syndrome
80
What are microsatellites?
segments of repeated DNA codes specific to an individual
81
What is microsatellite instability?
microsatellites are full of errors- indicates a problem with DNA repair
82
What is the function of PD-L1?
inhibits T cell proliferation
83
How do cancers destroy surrounding tissues?
increase expression of matrix metalloproteinases
84
what substance is produced by tumours that results in increased metabolism?
TNF
85
What are the histological features of a malignant cell?
increased N:C ratio; pleomorphism; hyperchromasia; mitoses; necrosis;
86
What is th restul of advanced glycation end products in DM?
abnormal crosslinking in vessel walls
87
What are the steps in atherosclerosis?
priamry endothelial injury; accumulation of lipids and macrophages; migration os SM; increase in size
88
Why does endothelial injury result in atheroma?
increased permeability and increased white cell adhesion- monocytes migrate through wall and beomce macrophages
89
Where does smooth muscle migrate from in atheroma?
from media to intima
90
what does the presence of smooth muscle chagne about the atheroma?
from fatty streak to fibrofatty plaque
91
What forms the centre of hte plaque in atheroma?
pool of extracellular cholesterol
92
Waht is arterial systole?
narrowing of arterial lumen; reduced elasticity; reduced flow in systole and tissue ischaemia
93
What is anaplasia?
malignant cells which are very undifferentiated (can't tell cell of origin)
94
How do G cells in the stomach appear?
fried egg
95
What do chief cells in the stomach secrete?
pepsinogen
96
What is the function of parietal cells in the stomach?
secrete HCl
97
What is the risk factor for endometrial hyperplasia?
obesity
98
What is endometrioid cancer associated with?
endometrial hyperplasia- obesity
99
What cancers are associated with HNPCC?
colorectal; endometrial; ovarian and TCC
100
What type of colorectal cancer is seen with HNPCC?
sessile (flat)
101
Where in the colon are tumours in HNPCC found?
right-side (normally left side is a lot more common)
102
What is the other name for a leiomyoma?
fibroid
103
What age groups get sarcoma?
children
104
What is a histiocyte?
stationery phagocytic cell in connective tissue
105
What is the response to foreign bodies?
granuloma
106
What cell is assocaited with granulomas?
histiocytes
107
Why do adenocarcinomas appear as signet ring?
mucin is pushing the nucleus to the edge
108
What is the prognosis of an adenocarcinoma with signet ring morphology?
bad
109
What does pink blobs on pathology indicate?
keratin- SCC
110
What is a psamomma body?
abnormal calcification in papillary cancer as well as serous ovarian carcinoma
