Hi! Thank you! And question for you! - Do you think the cardiovascular effects of valsalva are part of the reason why people hold their breath when they have a freeze response? Or what do you think about the idea that there's some kind of evolutionary benefit for a person doing this? - I'm a grad student studying to be a counselor and I've currently been researching how Heart Rate Variability (HRV)/bio-feedback/breathing and ADHD affect one another. I don't have a medical background, but I stumbled upon your video researching HRV. - Your explanation of valsalva reminded me of how people will instinctively and unconsciously hold their breath in situations that activate their fight/flight/freeze/fawn response. I don't fully understand if the cardiovascular effects of valsalva are beneficial in the short term. But it just got me wondering if performing valsalva (and the very similar holding of breath in those situations) might either help calm us so we can have increased awareness or think more clearly in order to survive; or perhaps do the cardiovascular effects prepare us to flee? Thanks!
Hi, at about 2:30 mark, I didn't get how the pulmonary vascular resistance gets increased. It said the negative pressure causes it, but not sure how neg. pressure leads to increases resistance. Thank you!
Basically he wants to convey that during inspiration there is pooling of blood in lungs decreasing the flow to left side decreasing CO there by decreasing BP as result of decreasing of CO the HR increases as a compensatory mechanism.
hello Dr.Umar, I like this video.... but i need to know the changes in cardiac cycle during inspiration...if SA node forming impulses...pls answer this question...
can you explain why the increased transmural pressure gradient of lungs, also causes the right atrium and great veins to dilate? that was not explained here. when the transmural pressure gradient increases it pushes the tube or sphere outwards, in this case the lungs. but the right heart is also dilating. it means the pressure is going backwards from pulm artery. why doesnt the pressure go forward into pulm veins?
J T, I agree that an increase in PVR leads to less blood flow to the lungs which leads to less flow to the left atrium but...…… In this video, it is said that an INCREASE in blood flow to the lungs leads to PVR which leads to less return to left atrium
@@faithbyrnes8819 and one more thing, if one vessel becomes dilatated, then the resistant should be decrease, ?ın the inspiration the pulmonary vessels expand right? and the resistance should be decrease?
They expand indeed but you do not know what has a "stronger" effect (pulmonary vessel expansion or increased blood volume). So the blood going to the lungs is too much and the capillaries there have an increased resistance (because of their very small radii) this is why it is mentioned like this I think.
