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Flashcards in Outline of disease processes Deck (30):
1

define cancer

disorderly growth of epithelial cells which invade adjacent tissue and spread by the lymphatics and blood vessels to other parts of the body

2

What is the characteristics of cancer cells

loss of contact inhibition
Increase in growth factor secretion
increases in oncogene expression
loss of tumour suppressor gene

3

What initiates cancer growth

chemical
physical
viral

4

Give example of chemical carcinogens

smoking
alcohol
nitrogen mustard - leukemia
aniline dyes - bladder

5

What is a physical carcinogen

ionising radiation

6

What is the mechanism of ionising radiation

chromosome translocation
gene amplification
oncogene activation

7

Give example of viral carcinogens

Herpes virus
Papillomavirus -cervical cancer
reterovirus - leukaemia/lymphoma
Hepatitis B - liver cancer

8

How do growth factors promote cancer

bind to cell membrane and regulate cell growth and function by promoting signal transduction pathway

9

What are growth factors composed of

polypeptide molecules

10

Growth factor stimulation is either

autocrine - GF produce acts on its self
or
paracinre - GF produced act locally or o neighbouring cells

11

What is an example go a growth factor

VEGF: vascular endothelial growth factor

12

What do oncogens do

promote growth

13

In folicular lymphoma what is the oncogenes

BCL2

14

What induces tumour suppressor genes

DNA damage and hypoxia

15

What is the most common mutated gene in tumours

P53

16

What is the normal function of tumour suppressor genes

DNA repair,
promote apoptosis

17

What promotes tumour growth

Increase in growth factor secretion
increases in oncogene expression
loss of tumour suppressor gene

18

How do tumours progress

metastasis

19

What is the pathway of metastasis

nvade basement membrane, moves into surrounding cells/tissues, invade blood vessels, tumours cells arrest in distant organ

20

What process must occur for tumour to surpass 2mm

angiogenesis - New blood vessel formation

21

What enzymes are involved with metastasis in the ECM

Matrix metalloproteinases (MMPs) eg gelatinases
Plasmin
Cathepsin

22

What is matrix metallaproteinases responsible for

degradation of most extracellular matrix proteins

23

What is plasmin responsible for

degrading blood plasma proteins

24

what is a cathespin

protease

25

Loss of what adhesion mechanisms causes metastasis

Cahedrins - transmembrane protein
Integrins - attaches cytoskeleton
CD44 - antigen

26

What is necessary for new blood vessel formation

degradation of ECM

27

What does a Anti VEGF antibody prevent

Growth factor interacting with receptors prevent transduction signal being sent, therefore tumour lies dormant

28

Why does our immune system not recognise cancer cells

PD1 present on T cell binds with PDL-1 ligand on tumour cells and suppress T cell action

29

What may high levels of PD1 or PDL1
protein expression inhibit

immune response

30

What kind of process is metastasis

organised