ILAs Flashcards
What is atherogenesis?
The formation of fatty deposits in the arteries
What are the four steps of atherogenesis?
- Endothelial cell injury
- Lipoprotein deposition
- Inflammatiory reaction
- Smooth muscle cell cap formation
List some factors that can result in endothelial cell injury
Tobacco, uncontrolled diabetes, hyperlipidaemia, hypertension
How does lipoprotein deposition cause a fatty streak?
The endothelium is injured or disrupted, causing lipoprotein molecules to gain entry, where they are then modified by oxidation of glycation. The LDL is inflammatory and able to be ingested by macrophages, creating foam cells and causing a fatty streak in the arterial wall
How does the fibrous cap of a plaque form?
Smooth muscle cells migrate to the surface of the plaque, forming the fibrous cap.
Are thin or thick capped plaques more likely to cause thrombosis?
Thin capped plaques are thought to be more prone to rupture or erosion, causing thrombosis
List some modifiable risk factors for atherosclerosis
High LDL cholesterol, and low HDL cholesterol, High blood pressure, obestiy, smoking, diabetes
List some non-modifiable risk factors for atherosclerosis
Family history, high blood pressure, being a post-menopausal woman, being over 45 for a man, diabetes
How does high LDL cholesterol promote plaque formation?
LDLs enter the artery walls and then can be phagocytosed by macrophages to form foam cells that promote inflammation.
How does low HDL cholesterol promote plaque formation?
HDLs remove cholesterol from foam cells, inhibit oxidation of LDLs, and limit the inflammatory response underlying atherosclerosis.
How does hypertension promote plaque formation?
In hypertension, there is increased dilation and contraction of arteries, damaging the endothelium. This endothelium is then scarred and thus thicker causing a narrower lumen and increased liklihood of atherosclerosis.
How does obesity promote plaque formation?
There is generally an increase in blood pressure as a result of higher demands in obesity
How does smoking promote plaque formation?
Toxins in tobacco smoke lower HDLs and raise LDLs. The nicotine and carbon monoxide also damage the endothelium. Nicotine is also a vasoconstrictor
How does uncontrolled diabetes promote plaque formation?
Diabetes drives inflammation and slows blood flow, dramatically accelerating atherosclerosis. Diabetes is also liked to obesity
How does increasing age promote plaque formation?
Arteries stiffen with age
How does being post-menopausal promote plaque formation?
A decline in oestrogen may be a risk factor in heart disease. Oestrogen is believed to have a positive effect on the inner layer of the artery wall, keeping vessels flexible
List some preventative measures that could be done to reduce risk of atherosclerosis
Reduce BMI, Reduce cholesterol intake, Lower blood pressure through medications, statins, Smoking cessation
What medications can be used to reduce the risk of atherosclerosis
Aspirin, statins, beta blockers
What is a co-benefit?
Additional benefits that arise from cutting greenhouse gas emissions, specifically health related events
What is anaphylaxis?
Anaphylaxis is a type 1 hypersensitibity reaction that causes a severe and potentially life-threatening reaction to a trigger such as an allergy
What are common triggers for anaphylaxis
Medication Food Insect stings General anaesthetic Contrast Agents Latex
What are some symptoms of anaphylaxis?
Feeling lightheaded or faint Breathing difficulties and wheezing Low blood pressure due to vasodilation A fast heartbeat= to combat low bp High temp= massive vasodilation Skin changes= Inflammatory process Low oxygen saturation= Bronchoconstriction Nausea and vomitting
What is the main chemical released in anaphylaxis?
Histamine
How is anaphylaxis treated?
Airways, circulation, breathing Stop trigger IM adrenaline IV fluids Chlorphenamine Hydrocortisone Oxygen
What does adrenaline do in anaphylaxis?
It targets blood vessels (alpha-1), the heart (beta 1) and bronchus (beta 2), causing vasoconstriction, positive inotropic effects and bronchodilation
Why are IV fluids administered in anaphylaxis?
To raise fluid levels to raise blood pressures
Why is chlorphenamine administered in anaphylaxis?
It is a histamine receptor blocker, meaning the effects of histamine will be less severe. H1 receptor antagonist
Why is hydrocortisone administered in anaphylaxis?
It is an agonist of the glucocorticoid and mineralocorticoid receptors meaning that there will be less inflammation= suppresses prostaglandins and causes vasoconstriction.
Why may adrenaline have to be administered twice after anaphylaxis?
It has a short half life
What test can be done to confirm anaphylaxis?
Mast cell tryptase
(Tryptase protein is released by basophils)
Also do FBC to rule out anaemia and rule out underlying infection
What factors are linked to an increased risk of anaphylaxis?
Certain medications Alcohol Exposure to new allergens Change in season Predisposition to asthma and eczema
What characteristics should a drug have in terms of protein binding and lipid solubility to work quickly?
- Low protein binding as binding lowers the free conc of a drug
- High lipid solubility so it can readily cross BBB
During anaesthesia, why must a drug be given throughout the procedure?
If not, the initial drug will diffuse into muscle, so plasma conc will lower and the patient will wake up
What is an agonist?
A drug that binds to and activates a receptor in the same way that the normal binding chemical would
What are the three types of agonists?
Full agonist
Partial agonist
Inverse agonist