BSCI450: CV disease

beta blockers reduce hypertension by…

reducing heart rate and stroke volume

hydrostatic pressure

pressure exerted by fluid at rest equal in all directions

oncotic pressure / colloid osmotic pressure

protein-driven osmotic pressure in blood that pulls water into vessels

filtration

hydrostatic pressure draws water out of capillaries

absorption

oncotic pressure draws water into capillaries

how much fluid flows out of capillaries per day

what system fixes this

3L

lymph

net pressure =

hydrostatic pressure - oncotic pressure

net filtration

hydrostatic > oncotic

net absorption

oncotic > hydrostatic

edema

ECF buildup due to excessive filtration or slow lymph return

what happens if a lymph node is blocked

edema build-up

lymph system capacity

4-5L/day

main cause of edema

liver failure -> low albumin -> low oncotic pressure

what is the source of hydrostatic pressure

heart

what kind of edema do you get if

right heart fails

left heart failes

systemic

pulmonary

compare normal output of the R&L heart

same

explain how heart damage causes edema

slow side -> blood pools in veins -> vein pressure increases -> blood can’t leave capillaries -> overall increase in hydrostatic pressure

auscultation

listening to heard sounds

stenosis

narrowing of valve -> no laminar flow

regurgitation

failure of valve to close -> backflow of blood

which murmur is loudest

aortic stenosis

how would aortic stenosis affect heart sounds

lengthens S1 to entire systole

how would mitral regurgitation affect heart sounds

lengthen S1 to entire systole

how would aortic regurgitation affect heart sounds

lengthen S2 to entire diastole

how would mitral stenosis affect heart sounds

lengthen S2 to entire diastole

2 key causes of hypertension

increased cardiac output, increased vascular resistance

what is afterload

amount of force heart must apply to push blood out of ventricles and into aorta

what is a risk of increased afterload

heart must work harder, increased risk of hypoxia

3 treatments for hypertension

diuretics

vasodilators

cardioinhibitors

diuretic

function

acts on kidney to reduce blood volume

vasodilator

example

function

Ca channel blocker

relaxes vascular smooth muscle, slows HR

cardio-inhibitor

example

function

beta blocker

reduces heart rate and contractility

good cholesterol

HDL

bad cholestrol

LDL

where do you now want to find cholestrol

blood stream

purpose of cholesterol

membrane fluidity, precursor to signals

where does cholesterol come from

liver or produced by cells

what holds cholesterol (hydrophobic)

lipoprotein carrier

statin

blocks cholesterol synthesis

HDL

transports cholesterol back to liver, cholesterol doesn’t go to arteries

LDL

delivers some cholesterol to cells, some to blood stream