Pathological Processes Flashcards
Why is troponin I/T detectable after a MI?
An area of cardiac muscle has undergone necrosis due to an infarction (lack of blood supply)
Cell membrane becomes leaky so it can be measured in blood
How does cirrhosis appear histologically?
Bands of fibrosis surrounding nodules of regenerating hepatocytes
What is an opsonin and give some examples?
A substance that coats foreign materials to make them easier to phagocytose
(CRP, IgG/IgM, C3b, C4b)
How does exudate form?
- Tissue injury results in vasodilatory mediators being released
- Inflammatory mediators cause endothelial cells to contract so vessel walls are leaky
- Plasma proteins leave the vessel and fluid collects in the interstitial space
- Fluid collects in extravascular space
What is diapedesis?
Passage of blood cells through blood vessel walls
What is a chemoattractant and give some examples?
Attracts inflammatory cells
(Endotoxin, thrombin, C3a/C4a/C5a, IL8)
Why is granulation tissue so red?
Contains many small blood vessels
How does a scar appear a year after and why?
White - small blood vessels regress
Hairless - hair follicles don’t regenerate in damaged skin
Stretched - elastic fibres don’t regenerate
What are abdominal adhesions?
Bands of fibrous tissue that form between abdominal tissues and organs
Give 2 reasons why pregnancy ^risk of DVT?
- Blood is hypercoagulable
- Baby = pelvic mass compressing venous flow
Why would you start a patient on LMWH instead of warfarin?
LMWH effective immediately
What is a saddle embolus?
A large emboli that straddles the bifurcation of the pulmonary artery
Which white cell is required for a histological diagnosis of chronic inflammation?
Epitheloid histiocytes
Which blood test is decreased in DIC?
Fibrinogen
How does coagulative necrosis appear histologically?
Loss of cell detail but ghost outline of tissue
What colour would a cardiac infarct be?
White
What are some differences between necrosis and apoptosis?
Inflammation present in N
Always pathological in N
Membrane intact in A
What are the functions of the compliment system?
Killing bacteria
Chemotaxins
Opsonisation
Features of inherited angio-oedema?
Swelling of face and airway and intestinal mucosa
(fatal in pharynx)
Functions of macrophages?
Phagocytosis
Secretion of chemical mediators
Opsonisation
Stimulating angiogenesis
Inducing fever
Which tissues always heal with a scar?
Cardiac, skeletal, neural tissue
What’s the difference between thrombosis and clotting?
Thrombus is pathological and inside the vessel
Clot is physiological and outside the vessel
How can a PE cause death?
- Ventilation-perfusion mis match
- ^resistance to flow = acute R HF = cor pulmonale
What causes an AAA?
Atherosclerosis weakens the tunica media
Why do both alleles of a tumour supressor gene need to be mutated but only one allele of a proto-oncogene?
Proto-oncogene = activating (encourage neoplasia)
Tumour supressor gene = deactivaitng (need both alleles destroyed for cell cycle to continue)
What’s cancer progression?
Accumulation of mutations over time.
How does HPV cause cancer?
HPV produces two proteins (E6 and E7) that inactivate tumour
suppressor proteins (RB protein and p53)
What are the 5 cancers that metastasise to bone?
Breast
Brostate
Bidney
Bhyroid
Bronchus
Which glands have ducts?
Exocrine glands have ducts, endocrine glands do not
Which is the correct order of events that a neutrophil must follow for phagocytosis?
Chemotaxis, activation, margination, diapedesis, recognition attachment, phagocytosis
What are the main cell types in chronic inflammation?
Macrophages and lymphocytes
What cells are seen in a foreign body granuloma?
macrophages
epithelioid macrophages
fibroblasts
When are Touton giant cell seen?
Fat necrosis and Xanthomas
What’s the function of tumour necrosis factor?
Migration and proliferation of fibroblasts
What is the main lymphatic drainage?
R lymphatic duct to R subclavian vein
Thoracic duct to L subclavain vein
Which part of the lymph node does lymphatic fluid enter?
Convex surface
What will the blood tests show for haemophilia A?
APTT is prolonged, but PT and bleeding time are normal
What will the blood tests show for a low platelet count?
Bleeding time prolonged, but not APTT or PT
From which cells do platelets emerge?
Megakaryocytes
What are the different types of plaque?
Fatty streak - flat lesion in the intima
Simple plaque - raised lesion in the arterial wall
Complicated plaque - produces symptoms
What are the different types of cells in regards to regeneration?
Stable cells - can replicate if they must e.g. liver
Permanent cells - unable to replicate e.g. heart
Labile cells - replicate constantly e.g. skin
Define carcinoma.
Malignant neoplasm of non-glandular epithelium
