ICS Flashcards
What is inflammation?
A reaction to an injury or infection involving cells such as neutrophils and macrophages.
How is inflammation classified?
Acute and Chronic
What cells are common in acute inflammation?
Neutrophils
What cells are common in chronic inflammation?
Lymphocytes & macrophages
Features of acute inflammation?
- Sudden onset
- Short duration
- Usually resolves
Features of chronic inflammation?
- Slow onset or sequel to acute
- Long duration
- May never resolve
What do neutrophil polymorphs do in inflammation?
- Short lived
- First on scene
- Cytoplasmic granules containing enzymes
- Die at scene of inflammation -Releases yellowy puss
- Releases chemicals that attract other inflammatory cells eg. macrophages
What do macrophages do in inflammation?
- Long life (weeks to months)
- Phagocytic
- Carry debris away (eg. to lymph nodes)
- Present antigens to lymphocytes
- Don’t always die
What do lymphocytes do in inflammation?
- Memory cells
- Long life (years)
- Produce chemicals which attract inflammatory cells
What do endothelial cells do in inflammation?
- become sticky
2. become porous (precapillary sphincters open = more blood flows through = more inflammatory cells)
Why is there redness and swelling in inflammation?
Red = increased blood flow
Swelling = more protein out, less/no liquid in
What cells are involved in chronic inflammation?
Lymphocytes, plasma & macrophages
What is a granuloma?
Aggregate of epitheliod histiocytes (macrophages) surrounded by lymphocytes.
Systemic effects of inflammation?
- Fever (pyrexia)
- Weight loss
- Amyloidosis
How do you treat inflammation?
Aspirin
NSAIDs - stop prostaglandin synthase
Betnovate cream
What is betnovate cream?
Corticosteroid
Can cause skin to atrophy
Powerful/potent anti inflammatory
Binds to DNA to upregulate inhibitors of inflammation and downregulate chemical mediators of inflammation.
What is prostaglandin synthase?
It is a chemical mediator of inflammation.
When is cell damage resolved?
When initiating factor is removed.
Tissue is undamaged or able to regenerate.
When is cell damaged repaired?
Initiating factor is still present. Tissue damaged and unable to regenerate.
What causes cirrhosis?
Architectual damage –> fibrous scarring –> regenerative nodules –> cirrhosis
How do skin abrasions heal?
Scab forms over surface, root hair cells and weat glads still there, grows up under the scab.
How do 1st intention (edges together) wounds heal?
Fibrin from blood - fibroblasts produce collagen.
How do 2nd intention (edges can’t be pulled together) wounds heal?
Fibroblasts grow from the edges of the wound.
What cells regenerate?
- Hepatocytes
- Pneumocytes
- All blood cells
- Gut epithelium
- Skin epithelium
- Osteocytes
What cells don’t regenerate?
- Myocardial cells
- Neurones
What is ischaemia?
Reduction in blood flow
What is infarction?
Death of cells due to ischaemia.
What is a reperfusion injury and why are they caused?
When blood is reintroduced after ischaemia cells produce damaging chemicals eg. superoxides.
Features of RCA obstruction?
- Inferior obstruction
- ECG changes in leads II, III, aVF
- Can involve post. septum
- 30% of cases
Features of LAD obstruction?
- Artery of sudden death
- Anterior infartion
- ECG changes in anterior chest leads
- 50% cases
Features of circumflex obstruction?
- Lateral infaction
- ECG changes in I, aVL and lateral chest leads (V4-6)
- 20% cases
What is a thrombosis?
Solid mass of blood constituents formed within intact vascular system during life.
What are the three components that make up thrombosis risk?
- Change in vessel wall
- Change in blood flow
- Change in blood constituents
How do you prevent thrombosis?
- Exercise
- Tight elastic stockings/socks
- Wiggle toes
- Aspirin = anti-platelet = stops platelet aggregation
What is an embolus?
Mass of material in the vascular system able to become lodged within a vessel and block it.
The most common is a piece of thrombus but can be others eg. gas.
What is hypertrophy?
Increase in size of a tissue caused by an increase in size of the constituent cells.
What is hyperplasia?
Increase in size of a tissue caused by an increase in number of the consituent cells.
What is atrophy?
Decrease in size of a tissue caused by a decrease in number of the constituent cells OR a decrease in their size.
What is metaplasia?
Change in differentiation of a cell from one fully-differentiated type to a different fully-differentiated type.
What is dysplasia?
Imprecise term for the morphological changes seen in cells in the progression to becoming cancer.
(Not yet but could become cancer)
What is apoptosis?
Programmed cell death.
What causes cells to apoptose?
DNA damage
How do cell apoptose?
- Enzymes released which kills nucleus
- Nucleus condenses
- Cells shrink
- Nucleus fragments
- Cleaned by macrophages
What is p53?
A protein which detects DNA damage and produces chemicals to cause apoptosis.
What is necrosis?
Mass death of cells.
What are the two types of necrosis?
Coagulative - thick and goey
Liquifactive - goes liquidy
What is caseous necrosis?
Has holes in it - common in TB
What are telomeres?
Section at the end of chromosomes, each time a cell divides the telomere shortens.
What affects how quickly a cell wears out?
-Cross-linking/mutations of DNA
-Loss of Ca2+ influx controls
-Cross-linking of proteins
-Telomere shortening
-Accumulation of toxic by-products of metabolism
-Free radical generation
-Peroxidation of membranes
etc.
What does UVB light cause?
Protein cross linking - makes collagen no longer elastic
What is osteoporosis in women?
Lack of aestrogen = increased bone resorption and decreased bone formation.
How are cataracts caused?
UV-B light causes protein cross linking which makes the proteins opaque.
What causes sarcopaenia (lack of muscle)?
Decreased growth hormones, decreased testosterone, increased catabolic cytokines.
Increasing testosterone does decrease sarcopaenia but increased GH doesn’t.
When does atheroschlerosis occur?
- In more deprived area
- Age 50+
Where is there rarely atherosclerosis?
Low pressure systems.
What’s in plaque?
- Fibrous tissue
- Lipids, cholesterol
- Lymphocytes, chronic inflammation
What are risk factors of atherosclerosis?
- Smoking cigarettes = free radicals, nicotine, carbon monoxide which cause damage to endothelial cells
- Hypertension = shearing forces
- Poorly controlled diabetes = superoxide anions, glycosylation products
- Hyperlipidaemia
Why does atheroslerosis form?
Endothelial cell damage.
They are delicate and metabolically active cells.
What is acute inflammation?
The initial and often transient series of tissue reactions to injury.
What is chronic inflammation?
The subsequent and often prolonged tissue reactions following the initial response.
What is tissue necrosis?
Death of tissues from lack of oxygen or nutriients resulting from inadequate blood flow.
Treatment for basal cell carcinoma?
Complete local excision
Breast cancer treatment:
It has spread to the axilla.. treatment?
Axillary node clearance
Breast cancer treatment:
It has spread to the rest of the body.. treatment?
Systemic chemo therapy
Breast cancer treatment: it hasn’t spread to the rest of your body or axilla.. treatment?
Surgery with or without axillary lymph node clearance.
What is adjuvant therapy?
Treatment given after surgical treatment.
What is carcinogenesis?
Transformation of normal cells to neoplasticism cells through permanent genetic alterations or mutations.
What is oncogenesis?
Formation of benign and malignant tumours.
What’s the difference between carcinogenic and oncogenic?
Carcinogen: agents thought to cause rumours
Oncogen: cancer tumour causing
Both act on DNA
What percentage of cancer risk is environmental?
85%
What are the carcinogens for hepatocellular carcinoma?
Hep B/C and mycotoxins
What are the carcinogens for Oesophageal carcinoma?
Linhsien chickens and very very hot coffee.
Increased incidence in Japan, China , Turkey, Iran
What are the carcinogens for Lung cancer?
Smoking
35,000 deaths/year
What are the carcinogens for Bladder cancer?
Anyone dye and rubber industries
What are the carcinogens for Scrotal cancer?
Higher risk in chimney sweeps. Polycyclic aromatic hydrocarbons.
What is Thorotrast?
- Colliidal suspension of thorium
- radiographic contrast medium 1930-1950
- 1947 post-thorotrast angiosarcoma
- it is radioactive
What are the classes of carcinogens?
- Chemical
- Viral
- ionising and non-ionising radiation
- hormones, parasites and micro toxins
- misc
What can polycyclic hydrocarbons cause?
Lung & skin cancer
Found in cigarettes and mineral oils
What can aromatic amines?
Bladder cancer
From rubber/dye workers
What can nitrosamines cause?
Gut cancer
In processed/smoked
What can alkylating agents cause?
Leukaemia
Used to kill certain cancers
Small risk in humans
What does increased exposure to UV(A & B) light increase the risk of?
Basal cell carcinoma, melanoma, squamous cell carcinoma
Much higher risk of xeroderma pigmentosum
Name some biological, hormonal carcinogens?
Oestrogen - increases mammary/endometrial cancer
Steroids- hepatocellular carcinoma
Name a biological, mycotoxin carcinogen?
Aflatoxin B - hepatocellular carcinoma
Name some biological, parasitic carcinogens?
Clonorchis sinensis - cholangiocarcinoma
Shistosoma - bladder cancer
What does asbestos cause?
Malignant mesothelioma, lung cancer, asbestosis
What is a neoplasm?
A lesion resulting from the AUTONOMOUS or relatively autonomous ABNORMAL growth of cells which PERSISTS after the irritating stimulus has been removed.
A new growth.
What is the epidemiology of neoplasm?
25% of population All ages Increased risk with age Mortality rate high 20% all deaths