Lesson 22: Topic 18 - High Systolic BP Flashcards
(48 cards)
what is the most important homeostatically regulated thing in our body that is always trying to be maintained?
mean arterial pressure
what are the consequences of high systolic blood pressure?
- aneurysm
- myocardial infarction
what is an aneurysm?
a rupture of wall of aorta
what is an aneurysm caused by?
high blood pressure that damages the artery itself
when the aorta is stretched out, what is it referred to as?
aorta with large abdominal aneurysm
aorta with large abdominal aneurysm is caused by?
having sustained pressure over time and every time you stretch our the aorta, the stretch could be permanent
what is an aortic dissection?
there is a rupture through the wall of the aorta that is a weak point and all of a sudden there is a pressure there that is going to push blood into the walls of the aorta which will weaken the structure
are aneurysms common in young?
no, unless there is a genetic predisposition like Marfan Syndrome
an abdominal aorta aneurysm is more common in what age group and what sex?
greater than 60 years and is more likely in males than females
what are a few things that become more common as you get around the 60 years of age mark?
- atherosclerotic plaque formation inside the arteries
- elastic properties of arteries (stretch becomes less elastic)
- causes aneurysms to be more common with age
what causes aneurysms to be more common in males than females?
caused by hypertension which is can be caused by smoking and drinking which are more common in men than women
what is another name for marfan syndrome?
spiderman syndrome
what is marfan syndrome cellularly?
a mutation in the extracellular matrix protein “fibrillin-1”
what is fibrillin-1?
the protein that attached elastic and non-elastic tissue to a structural membrane. it is the connective tissue between elastic and non-elastic tissue and anchors it to the basement membrane
patients of marfan syndrome appear how?
tall, thin, and arm span exceeds their height
- severe: caved in chest
the skin of patients of marfan syndrome appears how?
their skin can be stretched far with poor recoil
- this is because it is not anchored to the basement membrane
an aorta with normal fibrillin, what does the elastin fibre look like?
eastin fibre is well organized in a lasagna formation
an aorta with mutated fibrillin, what does the elastin fibre look like?
elastin fibres are disorganized leading to high risk of aortic aneurysm
true or false: height exceeds arm span in marfan syndrome
false. arm span exceeds height in marfan syndrome
what is the problem that causes the myocardial infarction?
the cardiac workload is too high to meet the oxygen demand
- work from heart does not get oxygen supplywhich leads to cardiac death
to maintain cardiac output when aortic pressure is elevated during hypertension, what must contract harder?
the left ventricle
- this increases oxygen demand by the cardiac muscle cells
when MAP increases during hypertension, stroke volume decreases IMMEDIATELY. why?
because aortic valve only opens when left ventricular pressure is higher than aortic pressure. so because aortic pressure is now higher due to hypertension, ejection of blood is shorter in time because the LVP is going to be higher than aortic for a shorter amount of time
- isovolumetric ventricular contraction time is going to be prolonged
- aortic valve opens later and closes sooner
ESSENTIALLY:
- higher aortic pressure means that a higher LVP is required to open the aortic value which means less blood is ejected in one cardiac cycle which leads to less stroke volume
MAP = “afterload”
what is afterload?
refers to the pressure that is distal to the ventricle that the heart must work against for blood flow to occur
- essentially pressure gradient
ejection of the hearts chambers only occurs when?
left ventricular pressure is greater than aortic pressure
