Vascular Physiology (Organ blood supply: part 6/6)

[9partyboy]

Why does the pulse rate in the carotid artery in the neck increase as we exercise if the amount of blood that the goes to the brain remains the same?

[JanessaEgg]

@9partyboy The pule for the whole body is the same...

[PotniaTheronVT]

Thank you for this 6-part series. It was so helpful for my online a&p class. Blessings to you and yours.

[PotniaTheronVT]

Thank you for this 6-part series. It was so helpful for my online a&p class. Blessings to you and yours.

[DLK0383]

so, how does total peripheral resistance affect blood flow?

[engcadco9]

Awesome....

[aleccs14]

after just finishing watching all your cardio physiology tutorials i just want to say you should be nominated for the teacher of the year award!!! thanks!extremely helpfull

[richardmcfarlane]

Thanks so much!

[bestmaxgurl]

thanks so much for making the subject so simplified to understand

[ToobYew]

Thanks, but my question is how can the blood "not return" to the heart at rest? I mean, compliant or not, veins are still tubes connected to arteries,,,,, so won't the blood flowing in the arteries "push" the blood that's in the veins?

[ToobYew]

I'm a little tired right now so can someone remind me again how exactly blood is "stored" in the veins?

Aren't arteries and veins ultimately all connected, and so whatever is flowing in the arteries will pass through the veins (as long as the heart is pumping).

So how can blood be "stored" in the veins?

Thanks.

[magbr611]

it's not that it keeps it storage in some chambers or anything, but since the veins can expand due to their collagen fibers it can contain more blood, and not all of this blood returns to the heart at rest. which means that the veins contain 75% of the blood and therefor stores it. it simply means that 75% of all blood is present in the veins at rest and that the veins may contract and get more blood into the heart and arteries for example during exercise.

[o2demand]

Veins have tremendous ability (venous capacitance) to hold volume (of blood)when venodilated therefore dec amount of blood returned back to the heart (venous return or preload)

[Marieannie2]

Veins are called capacitance vessels. Meaning, they accommodate large amount of blood, and since less active than the arteries, they are prone to blood clots, due to stagnation, blood that just sits there, like in being in an airplane for a long time.

[sairawaraich]

Awesome videos, thank you very much! Just a little correction - although you're RIGHT in saying "the brain is receiving the same AMOUNT of blood no matter what you're doing", it does not remain 15% but becomes something like 3% to the the brain during exercise as cardiac output increases from ~5 l/min to ~25 l/min.

[hyperhighs]

Oh yes, i know exactly what you mean. Thank you for the correction.

[JaniDaLa]

Isn't the total resistans (at 4:50) 1/R =1/R1+1/R2+1/R3 etc. ? Othervise the resistance would increase when you add a paralell blood vessel :P

But thanx for this videos their really great to refresh your memory :)

[hyperhighs]

Yes, you are correct. You certainly do decrease the resistance with each added parallel vessel. In fact, having watched this again, i realized that i should not have used the term "TPR" for those parallel vessels. TPR is the total resistance of ALL the arterioles in your body, and not just one group of parallel vessels.

[Traps59]

Your work is superb.  You make it very easy to understand unlike some professors.

[Jalhan]

Thanks so much for contributing in an excellent teaching manner to the understanding of vascular physiology.

It is very helpful and illustrative.

Please, keep up this excellent work with different subjects.

[mketema1]

great great leacture thanks walid