What is healing by primary and secondary intention?
Primary - Minimal scarring, epidermis regenerates
Secondary - Scab form, more scarring,
What are the 5 signs of acute inflammation?
Redness, swelling, heat, pain, loss of function
What is reperfusion injury?
Ischaemia followed by return of blood results in inflammation and oxidative damage.
What structural changes occur during reversible and irreversible hypoxia?
Reversible - Chromatin clumping, swelling, detachment of ribosomes from RER, cytoplasmic blebs
Irreversible - lysosome lysis, ER lysis, membrane defects, shrinkage chromatin, fragmentation chromatin, dissolution chromatin,
What are the 4 types of necrosis
Coagulative - Protein denaturation dominates. Leaves ghost outlines.
Liquifactive - Enzyme degradation dominates. Infection
Caseous necrosis - TB
Difference between dystrophic and metastatic calcification?
Both deposition of calcium in tissues
Metastatic - due to elevated serum calcium
Dystrophic - due to abnormalities of tissue
What is hereditary angio-edema? How is it treated?
Disorder of C1 inhibitor, results in excess bradykinin release and edema.
Treat with C1 inhibitor infusion.
List 5 cells involved in chronic inflammation
Macrophages, lymphocytes, plasma cells, eosinophils, giant cells
Main cell involved in acute inflammation?
Describe the process of fibrous repair
- Clot formed and Inflammatory cells invade.
- Clot replaced with granulation tissue. Fibroblasts migrate and produce ECM
- Fibroblasts contract to reduce volume. Scar occurs.
What are 2 methods through which growth factors can reach a cell?
- Extracellular signals via hormones etc.
- Loss of contact between adjacent cells and basement membrane
What is virchow's triad?
Factors that influence thrombosis formation.
- Abnormalities in blood vessel wall
- Abnormalities of blood flow
- Abnormalities of blood components
How would you treat a DVT?
Prevention - stockings, leg compression, heparin IV.
Treated - IV heparin, warfarin.
What is an atheroma, arteriosclerosis and atherosclerosis?
Atheroma - Lipid accumulation in tunica intima of arteries
Arteriosclerosis - Hardening of arteries due to atheroma
Atherosclerosis - Hardening of arteries due to DM or hyeprtension
Describe how atheromas occur
- Cholosterol accumulates in endothelium due to endothelial damage e.g. smoking.
- Macrophages enter wall and attempt to digest cholesterol and become foam cells
- Foam cells die and release contents
- Calcium salts and fibrous tissue accumulates and forms hard plaque.
- Endothelium over plaque ruptures and exposes collagen, recruiting platelets and forming platelet plug.
- Plug causes blood clot which can break off or result in ischaemia.
How would you differentiate a benign from malignant neoplasm?
Benign - round outer margin
Malignant - Irregular outer margin, may show necrosis
What needs to occur to a cell for it to form a tumour?
Tumour suppressor genes turned off and proto-oncogenes need to be turned on
How would you differentiate a benign and malignant neoplasm histologically?
Bengin - well differentiated, nuclei same size.
Malignant - well to poorly differentiated, nuclei different size
What alterations does invasion require?
- No adhesion between adjacent cells – reduction in E-cadherin
- No adhesion to basement membrane – reduction in integrin.
- Degradation of the basement membrane – Expression of proteases
What is xeroderma pigmentosa? Pattern of inheritance?
Cannot DNA nucleotide excision repair. Sensitive to UV --> mutations.
What is ataxia telangiectasia?
Cannot repair radiation damage. Lymphoid malignances.
What is hereditary non polyposis colon cancer syndrome?
Mutation in DNA mismatch repair genes.
What genes are associated with:
- Familial Adenomatous Polyposis
- Breast cancer
What is TNM staging? How is it used?
T = Size of primary tumour, T1 --> T4
N = Extent of regional node metastasis, N0 (no lymph node involvement) --> N3 (involvement of an increasing number of nodes)
M = Extent of distant metastatic spread, M0 (none) --> M1 (blood borne metastases)
Explain Dukes staging for colorectal carcinomas
Stage A – Invasion into but not through the bowel
Stage B – Invasion through Bowel wall
Stage C – Involvement of lymph nodes
Stage D – Distant metastases
What is grading of a cancer?
Level of differentiation of cancer. Less differentiated = more aggressive.
How does radiotherapy kill a cancer?
Triggers apoptosis by direct or ROS DNA damage that is detected by cell checkpoints.
How does chemotherapy kill cancers?
Alkylating drugs - Cross links DNA helix and promotes apoptosis.
Antimetabolites - Attach to DNA and prevents further replication occurring.
Give the tumour markers found in:
a) colon, pancreas, lung, stomach, heart
a) carcinoembryonic antigen
c) alpha fetoprotein
what is metaplasia
reversible change of 1 differentiated cell to another