so in sports and physical activity there's a thing which the body can do called redistribution or
blood redistribution also known as vascular sharp mechanism but what it basically allows our body to
do is redistribute the the cardiac output around our body according to demands and according to
where our body needs this blood the most so we can increase the delivery of blood to areas which
are working and we can decrease the delivery of blood to areas which aren't really working
and inside of that blood obviously we have oxygen and nutrients being carried to the site and then
the more blood that arrives or the less blood that arrives at the site that starts to impair the co2
and the lactate removal as well but obviously if we have a partial body that isn't really working
therefore there isn't much co2 or lactate being produced then we don't actually need much blood
being supplied to that area to take those limited supplies away so blood distribution
or redistribution is something that occurs during exercise now to this question here you can get
up to one or two more one or two marks just for stating the the different mechanisms involved
with this process and we have vasoconstriction and vasodilation so just knowing those two different
terms can get you points in the exam now if you can back this up with the definition even better
we're going to start off with vasodilation now dilation similarly similarly with our pupils
dilation means to get bigger or to expand in the the lumen size or the circumference and the area
within the space so dilation of the of the vessels they expand in size and in doing so more blood can
fit in them therefore more blood can flow through them therefore where these vessels are connected
to they're going to be fed a larger quantity of blood because the vessels feeding them with the
blood have gotten bigger there's a greater flow through them towards that area now what determines
what which tissue gets the most or the or this increased blood flow that determines or that's
determined by the activity and the exercise that we're doing what sort of demands are
being placed on our body are they or is that is the environment demanding from our quads or our
hamstrings or gastrocnemius or our arms or our core um is it a cardiovascular event which is
quite intensive for the respiratory muscles such as our abdominals or diaphragm or intercostals
have we just eaten a meal therefore our digestive system is going to require a larger amount of
oxygen and nutrients to allow that system to actually complete all of its processes properly
so vasodilation is when the arterioles you've got the artery the big thick vessels that carry
blood away from the heart we then split these down into smaller arterioles and it's these
which can dilate they can expand and they can allow a bigger blood flow to go through them
towards the areas of higher demand the opposite is vasoconstriction these arterials could in fact
contract or constrict so they actually become smaller than they are at rest therefore inhibiting
or limiting the amount of blood that can actually fit inside them therefore flow through them so by
combining these two mechanisms if we dilate the ones feeding the tissue that needs the blood
needs the oxygen needs the co2 and lactate removal mechanism
and we can constrict the tissues on route to the tissues that we're not actually really using
then we get a positive net effect the tissues that need the most blood get more
and because we've actually restricted blood going to the areas of the body that don't need it
there's a greater quantity of blood that can then be diverted into these dilated vessels going to
where we do need it so two ways the body can redistribute blood during exercise vasodilation
and vasoconstriction vasodilation means to expand the arterials which feed the working tissue
and vasoconstriction means to reduce the size to constrict the space inside the arterials which
are flowing towards the tissues which aren't being needed or aren't being used and that's
that i hope you found it useful and i'll see you again in the next exam question bye for now