Pathology Flashcards
How is Blood pressure defined?
High blood pressure is considered to be 140/90mmHG or higher
150/90mmHG or higher if your over 80
What is essential/primary hypertension?
usually no identifiable cause and develops gradually over many years
prevalence increases with age
What is secondary hypertension?
High blood pressure caused by an underlying condition
appears suddenly and usually worse than primary hypertension
What are some causes of secondary hypertension?
Renal artery stenosis
obstructive sleep apnoea
correction of the aorta
endocrine - hyperaldosteronism, cushings, thyroid disease
What is accelerated hypertension?
recent onset of high blood pressure carrying significant cardiovascular risk and with evidence of end organ damage
it requires urgent treatment
How can hypertension lead to heart failure?
Hypertension causes strain on the heart so it struggles to contract
it therefore becomes more muscular to compensate ( left ventricular hypertrophy)
being more muscular makes it harder to fill with blood (diastole)
both these factors can lead to heart failure
How can hypertension lead to Cardiovascular problems such as ischaemia/infarction?
Hypertension can lead to associated atherosclerosis in the coronary arteries so oxygen supply to the heart is reduced
the heart muscle may become starved of oxygen - ischaemia
if it is severe enough the heart muscle can die - Myocardial infarction
Pathophysiology of Atherosclerosis
damage to arteries speeds up atherosclerosis
this causes a thrombus to form which may embolism
causes:
Myocardial infarction
ischaemic stroke
blocking of oxygen reaching tissue
What are the different types of aneurysm?
true - localised permanent dilation of the artery
false- a blood filled space around the vessel which does not penetrate the fill wall thickness
clinical significance of an aneurysm
May rupture with significant blood loss and abdominal aortic aneurysm would cause likely death
what is a dissecting aneurysm?
intimal tear in the aorta and blood rushes through the tear
causes acute ischaemic damage
severe back pain
What is arteriosclerosis and what does it cause?
thickening, hardening and loss of elasticity of arteries which gradually restricts bloods flow to tissues
present as weakness, facial/lower limb numbness, confusion, vision problems
what is atherosclerosis?
A form of arteriosclerosis where fatty plaques and cholesterol build up in the wall
inflammatory response
not limited to small arteries - bifurcation
What are the risk factors of an atheroma?
hypercholesterolemia
smoking
hypertension
diabetes
obesity
sedentary lifestyle
unhealthy diet
alcohol
male
age
low birth weight
family history
How does a atheroma form?
1) there is damage to the endothelium causing accumulation of cholesterol
2) an inflammatory response is caused
3) monocytes enter artery wall and turn into macrophages which form foam cells under the endothelium causing fatty streaks
4) in the artery wall the foam cells released there contents forming an atheroma (atherosclerotic plaque)
5) When BP increases the endothelium ruptures over the plaque exposeing the collagen
6) platelets stick to the collagen forming a platelet plug and then a blood clot
7) prothrombin turns into thrombin by the release of thromboplastin
8) a tangled mesh is formed which traps blood cells and forms a thrombus
