Cardiovascular system Flashcards
What is atherosclerosis?
Fibrofatty lesions in the medium and large arteries - aorta, coronary, cerebral, femoral, form on the intimal lining.
Begins as insidious process - S/S not displayed for many years.
Complications - IHD, CVA, peripheral vascular disease - 30% UK deaths.
Artery wall thickens -> accumulation of WBC’s & proliferation of smooth muscle cells on tunica intima -> fibro-fatty plaque -> arteries harden.
Chronic inflammatory response in wall due to WBC’s.
What is the process of atherosclerosis?
> Foam cell formation: LDL cholesterol accumulates on wall - undergoes chemical changes -> signals to WBC’s to latch onto endothelial cells on wall, penetrate the intima -> inflammatory response -> devour LDL -> fat laden foam cells.
Fatty streak forms - earliest atherosclerotic plaque - found in paeds.
Growth -> fibrous cap.
Foam cells release substances that can destabilise the cap -> rupture, clot -> break away and occlude.
LDL - bad.
HDL - good, need more HDL than LDL.
What are the three causes of atherosclerosis?
> Traditional: age, high LDL, low HDL, HTN, DM, smoking.
> Underlying: obesity, sedentary lifestyle, atherogenic diet, stress.
> Emerging: insulin resistance, metabolic syndrome.
List the risk factors for atherosclerosis:
> Hypertension: ^ risk by 2-fold, more common in M, women affected in middle age (menopause - oestrogen), primary (idiopathic) - no cause ID’d 95% of cases, secondary - ID’d cause (renal/endocrine).
> Hyperlipidaemia: xs lipids/triglycerides/phospholipids/cholesterol, HDL/LDL, HDL made in liver carries cholesterol from peripheral tissues to liver for excretion, regular exercise, moderate alcohol and statins can ^ HDL.
> Smoking: endothelial damage -> stopping red. risk.
> T2DM: ^ risk by 2-fold, w/ HTN by 8-fold.
> Visceral fat: in abdo cavity around liver, pancreas, intestines, high amounts -> T2DM, CVD.
Describe the clinical manifestations of atherosclerosis:
> Narrowing of vessel -> ischaemia.
> Plaque haemorrhage/rupture vessel obstruction.
> Thrombus/embolus due to endothelial damage.
> Aneurysm due to vessel wall weakening.
> Large vessels - thrombus and wall weakening.
> Medium vessels - coronary, cerebral - ischaemia, infarct.
> Affects any organ/vessel - most common coronary, cerebral, lower extremities, small intestine.
