MOD Flashcards
Give the function and an example of a heat shock protein
Work to mend the misfolded proteins in the cell. An example is uniquitin
Oncosis is cell death with swelling, what are the three stages of oncosis?
Pyknosis - shrinkage of the nucleus
Karyorrhexis - nuclear fragmentation
Karyolysis - resorption of the nuclear membrane
Give four types of necrosis
Coagulative
Liquefactive
Caseous
Fat
Give the difference between coagulative and liquefactive necrosis
Coagulative - protein denaturation dominates enzyme release
Liquefactive - enzyme release dominates protein denaturation
Describe the ghost outline and give the type of necrosis it occurs in
The preservation of the cellular architecture seen in coagulative necrosis
Which condition is closely associated with caseous necrosis?
Tuberculosis
Which disease is closely associated with fat necrosis?
Acute pancreatitis and breast trauma
Name an organ that undergoes white infarction
Heart
Kidney
Spleen
All have dense tissue to stem the bleeding
Name two organs that undergo red infarcts and the reason why they show this
Brain - poor stromal support
Lungs- numerous anastomoses
What is the main regulator of apoptosis (cell death with shrinkage)?
P53
Which complex, created in the mitochondria, induces the destruction of the cell in apoptosis?
Caspases
What is the difference between stable and labile cells?
Stable cells have arrested in G0 but can divide again if they leave this phase.
Labile cells continuously divide e.g. epidermal cells
Describe the process of fibrous repair
Fibroblasts release collagen into the area, myofibroblasts contract to reduce the area of injury, angiogenesis occurs to vascularise the area
What is the difference between primary and secondary intention healing?
Primary - the edges are opposed and the epidermis can regenerate with granulation in the dermis
Secondary - the edges are unopposed and myofibroblasts must response them. Keloid scarring in the epidermis and eschar formation in the dermis
Give the four cardinal signs of acute inflammation
Dolor (pain), rubor (redness), calor (heat) and tumor (swelling)
Histamine is secreted from which cells?
Mast cells
Give the effects of histamine
Vasodilation and increasing vascular permeability
Give the difference between transudate and exudate
Transudate is due to a hydrostatic pressure disturbance and so has a low specific gravity
An exudate is the secretions seen in inflammation and so has protein inside and has a higher specific gravity
Give the four stages of neutrophil infiltration at an inflammation site
Margination, rolling, adhesion and emigration
What are the effects of endogenous pyrogens and give an example
Stimulate the thermoregulatory centre in the hypothalamus to induce a fever. IL-1 and TNF-α
What is the primary leukocyte of acute inflammation?
Neutrophil
Which cell can the monocytes differentiate into?
Macrophages
Describe the resolution process of acute inflammation
Lymphatic drainage of exudate, phagocytosis of foreign bodies and regeneration of damaged tissue
Define chronic inflammation
Inflammation lasting more than 12 weeks with associated fibrosis
What is the main leukocyte of chronic inflammation?
Lymphocytes (T and B)
What is the generic formation of a giant cell?
The fusion of many macrophages
What is granulation tissue?
The walling off of the injured site with macrophages with central necrosis due to avascularisation
Describe the appearance of Langhan’s giant cells
Crescent shape of marginalised nuclei. Seen in TB
Describe the histological appearance of foreign body giant cells
Central, disorganised nuclei that overlap. Seen in foreign body invasion
Describe the histology of a Touton giant cell
Completely encapsulated by a ring of marginalised nuclei. Often seen in areas with a high lipid content e.g. fat necrosis
What are permanent cells and give an example
These are cells that have completely arrested and are unable to divide further. Skeletal muscle, brain neurones
What is Hayflick’s number?
The maximum number of divisions that a cell can undergo before the telomere length is too short to allow further growth. Quoted at 61.3
Give one physiological and one pathological case of hyperplasia
Endometrial hyperplasia in menstrual cycle
Thyroid hyperplasia in gone formation
Give one physiological and one pathological cause of hypertrophy
Muscle bulk in exercise training
Cardiac hypertrophy in cardiomyopathy
Give a physiological and pathological cause of atrophy
Ovarian atrophy in post-menopause is physiological
Denervation atrophy is pathological
What is metaplasia? Give an example condition
Change of one cell type to another. E.g. Barrett’s oesophagus
What is the fatty streak?
Lipid infiltration in the intimal lining of arteries
Describe a simple plaque
Propagation of the fatty streak so that it has an irregular outline and is widely distributed
Describe the complicated plaque and give a condition it predisposes to
Calcification of the atheroma surface to form a fibrous cap. Can predispose to aneurysm
What are foam cells?
Macrophages that have ingested too much lipid in the artery intima that they now contribute to the plaque
Give some risk factors for atheroma
High cholesterol, male, age, hypertension, diabetes
Give the benign and malignant tumour name of a gland
Adenoma is benign
Adenocarcinoma is malignant
Give some structural changes seen in malignant cells
Poor differentiation
Increased nuclear:cytoplasmic ratio
Mitotic figures
Give some behavioural changes of malignant cells
Immortality - as seen in HeLa cells
Loss of contact inhibition
Loss of anchorage dependence
Low requirement for growth factors
Give some functional changes seen in malignant cells
Decreased adhesion between cells
Tissue factor production, increasing clotting
What are foci of necrosis?
A central portion of necrosis seen in malignant tumours. Associated with a poor prognosis
Give the ways that metastases can spread
Blood
Lymph
Direct spread
Describe the seed and soil hypothesis
The seed is an opportunistic portion of the primary tumour that enters a serosal surface. The soil is a distant tissue site that supports the seed for growth as a metastasis. The seed must be slippery enough to pass in the blood/lymph but adhesive enough to adhere to the new soil
What factors must a metastasis do to become a new tumour?
Separate itself from the primary Digest through the basement membrane Escape systemic defences Penetrate the new endothelium Induce angiogenesis to create a secondary
Give the two commonest paraneoplastic syndromes
Small cell carcinoma of the lung producing ADH
Squamous cell carcinoma of the lung producing PTH
Why are many cancer patients in a hypercoagulable state?
Platelets are activated by tumour secreted ADP
Tumours secrete tissue factor
Give some chemical carcinogens
Pollution
Smoking
Alcohol (promotes turnover of cells)
Diet
What are the Japanese and American common GI cancers?
Japanese have stomach cancers, Americans have colon. This is due to diet
How do tumours divide indefinitely?
By stimulating proto-oncogenes and switching off tumour suppressor genes
Give the most commonly changed tumour suppressor gene
P53
Give the staging of Dukes classification and the cancer assessed
Colon cancer A - not through bowel wall B - invasion through bowel wall but not including lymph nodes C - lymph node involvement D - widespread metastases
Give the staging of Ann Arbor classification and the cancer involved
Lymphoma 1 - one lymph node involved 2 - two regions on one side of the diaphragm 3 - both sides of the diaphragm involved 4 - diffuse involvement of lymph nodes
Give the cancers that the following markers correlate to; bence-jones protein, PSA, CEA, Alpha-fetoprotein
BJP - multiple myeloma
PSA - prostate ca
CEA - colon ca
AFP - hepatoma and germ cell tumours
Describe TNM staging
Tumour size 0-4
Nodal involvement 0-3
Metastases 0 or 1
Give the three stages of haemostasis
Artery contracts
Platelet plug formation
Fibrin infiltrate to stabilise the platelet plug
Give some platelet activators
Thrombin
Collagen surfaces
ADP
Give the function of thrombin
Cleaves fibrinogen to fibrin
How is a blood clot dissolved?
Dilution of clotting factors by the blood flow
Natural anticoagulants produced by the liver
Give the function of plasmin
Enzyme responsible for fibrinolysis
Circulates as plasminogen and is activated by tissue plasminogen activator (tPA)
What is the function of Von Willebrand factor?
Found on the endothelial wall to favour clotting
What is Virchow’s triad of thrombus formation?
Changes to vascular wall
Changes in blood flow
Changes in the blood
How would you differentiate between a thrombus and a post-mortem clot?
Thrombi are laminated with lines of Zahn
Post-mortem clots are shiny and never laminated
What is disseminated intravascular coagulation?
This is a complication of another condition (commonly sepsis) where all the clotting factors are used up and so the person is at risk of haemorrhage
Give some forms of emboli
Thrombo-embolus Gas Fat Amniotic Foreign body
