Intro Flashcards
Where are endothelial cells found and what happens to them during inflammation?
Line blood vessel walls
Become sticky during inflammation
What do fibroblasts produce?
collagen
Give an example of acute inflammation
Appendicitis
Give an example of chronic inflammation
TB
Which cell type are absent in chronic inflammation?
Neutrophils
What are prostaglandins?
Chemical mediators of inflammation
What is healing by first intention?
Suture will fix wound, bringing edges together. Will regrow with collagen fibres.
What is healing by second intention?
Skin edges cannot be brought together, therefore skin graft may be required.
What is brain gliosis?
Repaired brain tissue, a form of fibrosis.
Which tissues are able to regenerate? (5)
Osteocytes, skin/gut epithelium, blood cells, pneumocytes, hepatocytes.
Are nerves able to regenerate?
Only peripheral nerves are able to regenerate
What is turbulent flow?
Cells aren’t flowing in the centre of the vessel
How is fibrin produced?
From activation of fibrinogen by platelets
Describe the process of thrombus formation from endothelial injury
Endothelial injury-collagen exposes-platelets attach- platelet aggregation occurs-RBC and fibrinogen attach-fibrin forms-thrombus
What is a thrombus?
A solid mass of blood constituents formed within an intact vascular system during life
Changes in which three factors will result in a thrombus?
Change in vessel wall
Change in blood flow
Change in blood constituents
What is an embolus?
Mass of material in vascular system that lodges within a vessel wall to block it
What is ischeamia?
A reduction in blood flow and limit of oxygen
What is the difference between ischaemia and infarction?
Infarction is cell death due to ischaemia, ischaemia is reduced blood flow
What are the 2 blood supplies of the lungs?
Pulmonary and bronchial
What are the 2 blood supplies of the liver?
Hepatic artery and portal vein
What is a granuloma?
A circular mass of macrophages in inflammation
What are risk factors of atherosclerosis?
Cigarettes, high BP, diabetes, age, hyperlipidaemia
What makes up a plaque in atherosclerosis?
Fibrous tissue, cholesterol, lymphocytes
What is apoptosis?
Programmed cell death
What is necrosis?
Multiple cell death often caused by infarction
What type of cells will undergo apoptosis?
DNA damage, fully differentiated cells (e.g. top skin layer)
Give an example of diseases with too much and too little apoptosis
Too much- HIV (lymphocytes)
Too little- Cancer
What chromosomal abnormality causes Down’s syndrome?
Trisomy 21
Define Hypertrophy
Increased size of tissue due to increased SIZE of cells
Define Hyperplasia
Increased size of tissue due to increased NUMBER of cells
What type of growth disorder is benign enlargement of prostate?
Hyperplasia
What is atrophy?
Loss of tissue or cell shrinking
Define metaplasia
Change in cell type, differentiation from one to another
What is a common cause of metaplasia?
Smokers bronchi can metaplase from ciliated to squamous
Define displasia
Changes to cells becoming cancerous
What is progeria?
Accelerated ageing
What is dermal elastosis?
Loss in skin elasticity
What is sarcopenia?
Loss in muscle tone
what is angiogenesis in relation to cancer?
growth of new blood vessels for tumour cell supply
which cancer types commonly metastase to bone? (5)
prostate, lung, breast, kidney, thyroid
which cancer types commonly metastase to liver? (3)
pancreas, stomach, colorectal
what type of tumour is chemotherapy a good treatment for?
fast dividing tumours
where are commensal bacteria commonly found?
colon
what are opportunistic bacteria?
bacteria causing disease when host is compromised
what is virulence?
pathogenicity of organism
which areas of the body are sterile?
blood, CSF, kidneys, bladder, gallbladder, lungs, eyes
when using gram stain, which colours do gram positive and gram negative bacteria stain?
positive- purple
negative- pink
what shape are coccus bacterium?
spherical
what shape are bascillus bacterium?
rod
what is a diplococci bacterium?
paired bacteria
what shape is vibrio bacterium?
bent rod shaped
what shape is spirochaete bacterium?
spiral
what are endotoxins?
components of gram negative bacterial cell wall
what are exotoxins?
toxin secreted by bacteria into surroundings (both gram positive and negative)
what is atopy?
tendency to develop allergy
what is an allergy?
abnormal reaction to harmless foreign material
what is an intolerance?
no involvement of the immune system, adverse effects in response to food or drug
what levels are normal for IgE in the blood of a healthy individual and why?
negligible due to short half life of 2 days
where are high affinity IgE receptors commonly found?
mast cells, eosinophils, basophils
where are mast cells produced?
bone marrow
what do mast cells contain?
granules: histamine, proteases, proteoglycans, chemotactic factors
which protein is required for mast cell production?
c-kit protein
what activates mast cells?
allergens
sometimes: enterobacteria phagocytosis, antigens of bacteria
what shape are mycobacterium?
rod
which illnesses are caused by mycobacterium?
leprosy, TB
what is unusual about mycobacterium and macrophages?
they survive digestion of macrophages
what are the characteristics of mycobacterium?
aerobic, non motile, bacillus, thick waxy coat, non spore forming, weakly gram positive, slow growing
what is acid fast?
a characteristic of mycobacterium (and others) due to high lipid content, meaning they resist usual staining methods, useful to stain for acid fastness as very few organisms will be positive
what component of mycobacterium causes their acid-fastness?
mycolic acid of cell walls (high lipid content)
what forms due to the balance between mycobacterium and macrophages?
granuloma, a wall forms to starve mycobacterium causing metabolic shut down
what is the drawback of granuloma formation in presence of mycobacterium?
granuloma starves mycobacterium causing metabolic shut down, but mycobacterium can survive for years like this and then restart when granuloma eventually fails
what are characteristics of tuberculoid leprosy?
granuloma
nerve damage
tissue damage
what are characteristics of lepromatus leprosy?
extensive skin lesions
poorly formed granuloma
How is hepatitis A transmitted?
faecal/orally
how is hepatitis B transmitted?
sexually/blood
what does chronic hepatitis B/C commonly lead to?
liver cancer
which virus commonly causes cervical cancer?
HPV- human papilloma virus
which latent virus leads to shingles?
herpes
what are characteristics of viruses?
grow only in host cell
no cell wall
possess only DNA or RNA
which cells and receptors does HIV target?
CD4 cells of T cells
how does rotavirus cause diarrhoea?
atrophy of villi in gut epithelium, absorption impaired, osmolality increased
how does HPV increase risk of cervical cancer?
causes switching on of specific proteins which repress cell death– excessive growth
how does Hep B increase risk of liver cancer?
lots of cell proliferation in response to cell death
what is invasiveness in relation to microorganisms?
ability to penetrate mucosal surfaces
what is microbiome?
totality of microorganisms in an environment
what is a biofilm?
layer of one or more types of microorganisms forming a colony over a surface
what is an example of biofilm in the human body?
dental plaque
what makes biofilms difficult to remove?
sharing of resistant properties between organsims, not necessarily homogeneous
which immunoglobulin responds to worms?
IgE
what is myalgia?
widespread muscular pain
what are the common symptoms of malaria?
fever, myalgia, tachycardia, abdo discomfort, dehydration/ dark urine
RECENT TRAVEL + FEVER
which categories of antibiotics work on cell wall?
beta lactams, glycopeptans
what type of antibiotic are penicillins?
beta lactams
how do bacteriostatic antibiotics work?
prevent bacterial growth by inhibiting:
protein synthesis
DNA replication
metabolism
how do bacteriacidal antibiotics work?
kill bacteria by removal of cell wall
What is MIC in relation to antibiotics?
minimum inhibitory conc
minimum conc of antibiotic required to stop microbial growth
what are the 3 types of horizontal transfer in bacteria?
conjugation, transduction, transformation
how does conjugation in bacteria work?
sex pillus forms and plasmid is transferred between bacterium
how does transduction in bacteria work?
virus affecting bacteria transfers genes from one bacteria to another
how does transformation in bacteria work?
taking up free floating DNA from another bacterium and integrating into genome
which class of antibiotics is MRSA resistant to?
beta lactams
what is a retrovirus?
a virus containing RNA that becomes DNA once within host cell using reverse transcriptase enzyme
what is the process of retroviral invasion into host cell (8 steps)
- ATTACHMENT to receptors on host cell
- ENTRY into host cell
- UNCOATING of virus
- REVERSE TRANSCRIPTASE makes RNA into DNA
- DNA is INTEGRATED into host cell DNA
- PROTEIN SYNTHESIS occurs forming viral proteins too
- ASSEMBLY of new virons occurs
- BUDDING of new virons from host
which cells are the first to be infected by HIV?
macrophages
what is the term for someone living with HIV for a while without AIDS developing?
long-term non-progressors
why do antiretroviral drugs struggle to eradicate HIV completely?
they only target replicating cells so a dormant population remain
what are clinical presentations of HIV?
lymphadenopathy, flu like symptoms, persistent infections e.g. shingles
how is AIDS identified?
CD4<200 or ‘aids defining illness’
