L1 Flashcards
name the blood vessels of the cardiovascular system
arteries arterioles capillaries venules veins
how many liters of blood in the body
4-6L
what are the 3 reasons why we need the cardiovascular system
- To provide adequate supply of O2 and nutrients
- To remove unwanted metabolic waste (CO2 and H+)
- To transport substances and heat
why are the 3 roles of the cardiovascular system important for survival
because diffusion is slow
Our body has to do these things all the time but if we did it jest by diffusion it would be too slow as there is too large a distance for everything to diffuse across.
note: That is why very small things often don’t have a circulatory system but large animals always do
what is the difference between the micro and macroscale of the cardiovascular system (CVS)
micro = diffusion across short distances. this happens in the capillaries in the lungs and vessels
macro = bulk flow over long distances around the body
what are the 3 things that micro and macroscale of the CVS allow for
- Quick delivery to the capillaries
- Optimill exchange
- Quick return to the lungs
very basically describe the structure of the heart
outermost layer is the pericardium which is a membranous sac
then there is the myocardium which is the cardiac muscle
then there is the arteria and the ventricles (the ventricles walls are thicker)
the left ventricle is thicker than the right
there are fibrocartilage rings which are known as the valves which control direction and flow of the blood through the heart
what are the different valve names in the heart
the atrioventricular valves are the bicuspid/mitral (left heart) and the tricuspid valve (right heart)
the semilunar valves are the aortic (left) and pulmonary (right) valve
describe the process in which the valves open
the opening and closing of the valves is a passive pressure dependent process. the valves can only open one way as they are what allow for unidirectional flow, therefore when pressure is high on one side they will open, but when it is higher on the other they will close
We need a CVS to….
A) remove metabolic by-products, such as H+
B) ensure adequate supply of CO2 and nurturance to the organs
C) transport of heat
D) answers A and C are correct
D
what are intercalated discs
they are what connect each cardiac muscle sell to each other so that the many cells are able to act as one.
this is where gap junctions are located for ion transport and electrical coupling
what are the physiological factors of the CVS
CO (heart rate x SV)
peripheral resistance
what are the physical factors of the CVS
arterial blood volume
arterial compliance
what does mean arterial pressure (MAP) show
how difficult it is to move blood around your body
what is CO
CO is the volume of blood ejected by EITHER ventricle in 1 minute
the amount of blood leaving your heart every minute
how do you calculate MAP
MAP (mmHg) = CO (L min-1) x TPR (mmHg / L / min)
pressure = flow x resistance
what is the equation for CO
CO (L.min-1) = SV (L.beat-1) x HR (BPM)
what is SV
stroke volume is the volume of blood ejected from either ventraical
why do we need CO to increase during excersize
This is because you body is metabolizing so quickly that it needs nurturance fast and to get rid of waste products fast
what is Poiseuille’s law
vessels in a series or parallel determine total peripheral vascular resistance
R = 8nl / 3.14.r^4
what is pressure = to
P = QR
flow x resistance
why is the radius the most important for determining TPR
because it is the only thing that can be changed physiologically
therefore r^4 is the most important determinant
describe the pressure in the ventricles
it is very pulsatile from about 5mmHg to max (120 or 250)
describe the pressure in the arteries
it is again very pulsatile frome diastolic to systolic. the pressure ranges from 60 mmHg to max
not that policitility has dropped a little
describe the pressure in the arterioles
this is where the pulicitile pressure dissipates and from then on the blood is at a constant diffusent pressure
describe the pressure in the capillaries, venules and veins
low pressure and non pulsatile
explain elastic reservoir
can also be called windkessel or air chamber
it is the intermittent injection of blood into the aorta from the left ventricle
large arteries are distensible meaning that they stretch and recoil to dampen the pulsatility which keep capillary flow constant during the cardiac cycle
how do arterioles/arteries dappen out the pulsatile nature
because of their elastic nature. when the walls are stretched they are storing energy which is release’s when the walls are relaxed again
