Cardiac Output & Venous Return Curves | 7.08 CVS PHYSIOLOGY

This video starts with Compliance and Elasticity and how the two concepts apply to Veins and Arteries, before moving on to Mean System Pressure / Mean Systemic Filling Pressure which is an extremely important concept if we are to understand the Cardiac and Vascular Function Curves. We close off with Active Hyperemia vs Passive Hyperemia.
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#USMLE #STEP1 | FCPS Part 1 | COMLEX LEVEL 1 | NCLEX | MCAT | First Aid

Пікірлер: 191

  • @jaredcovers218
    @jaredcovers2183 жыл бұрын

    Best explanation I’ve seen so far!!! Can’t believe im watching this for free!!! This one’s definitely better than Physeo’s or BnB’s explanation!!! Keep it up!!!

  • @tayyabriz9701

    @tayyabriz9701

    2 жыл бұрын

    agree completely

  • @AestheticMEDICO

    @AestheticMEDICO

    2 жыл бұрын

    agree

  • @acetylcoa8559

    @acetylcoa8559

    2 жыл бұрын

    exactly after 31 mis of physeo and 16 mins of b and b i was still confused but he finally made this concept clear for me

  • @Batool1111

    @Batool1111

    Жыл бұрын

    agree 👍🏼

  • @ilsakhan9631
    @ilsakhan96314 жыл бұрын

    I just can't believe tht cardiac output and venous return curves can be this easy !! May God bless u !!! This video is more than just brilliant!!!!!

  • @733-vandanaharitha5
    @733-vandanaharitha54 жыл бұрын

    After listening some hundreds of lectures about venous return I came to know that this was the really good and amazing lecture that this gives me clarification. And want more lectures like this....

  • @GRABtheMD

    @GRABtheMD

    4 жыл бұрын

    Good to know it's helping 😊

  • @sililly1379
    @sililly13795 жыл бұрын

    Wow. That's deep physiology made easy. Thank you, Grab the MD, for taking the time to make these videos.

  • @evegroult5184
    @evegroult5184 Жыл бұрын

    Genuinely the best video. Love my lecturers but I was so lost and double guessing myself and you explained everything so nicely that I am now excited about this topic. Thank you so very very much!

  • @mrmuppetdzn4421
    @mrmuppetdzn44212 жыл бұрын

    4 minutes into the video, and already gained a subscriber, really thank you !

  • @Cornbreadddd
    @Cornbreadddd Жыл бұрын

    Wow, I've never understood this graph and tried so many videos to understand it, but this video made it obvious in less than 5 minutes. Thank you

  • @krsjhn01
    @krsjhn014 жыл бұрын

    WOW! ON POINT! THANK YOUU SO MUCH!!! Please do more CV physiology!

  • @softcloud3949
    @softcloud39492 жыл бұрын

    Best explanation of this topic I've found! Thank you so much for this, it's really helpful :)

  • @ayushisachan2549
    @ayushisachan2549 Жыл бұрын

    The best video to exist on this topic . Thanks a lot for this

  • @MrCOOKIEMONSTA4
    @MrCOOKIEMONSTA43 ай бұрын

    Absolutely amazing video!!! Compliments and much appreciated

  • @minadz1279
    @minadz1279 Жыл бұрын

    Got what i was looking for in under 3min in your video, thank you for making this easy for me Great explanation

  • @coreycarney4776
    @coreycarney47764 жыл бұрын

    This was so helpful! Thank you!!!

  • @kalpanagosai1709
    @kalpanagosai17092 жыл бұрын

    Sadness is such golden videos being suggested after almost a year of step-1. This is an amazing channel, I am done with step-1 yet I am binge watching the videos on this channel. Great stuff.

  • @GRABtheMD

    @GRABtheMD

    2 жыл бұрын

    Thank you. That's high appreciation. This comment goes to the top!

  • @utkarshsodyssey903
    @utkarshsodyssey9034 жыл бұрын

    Brilliant illustration 🎉👍🏻 more videos please!!

  • @lryuzaki8018
    @lryuzaki8018 Жыл бұрын

    You deserve 30000000 subs! thank you!

  • @MrAndyroni
    @MrAndyroni2 жыл бұрын

    With this video, you've got yourself a new sub. It was electric

  • @coolkitty154
    @coolkitty1542 жыл бұрын

    Incredible explanation, thank you!

  • @divaroshan3797
    @divaroshan37973 жыл бұрын

    This video is a jackpot man!

  • @kritikasriram6518
    @kritikasriram65185 ай бұрын

    Great video with crystal clear explanations, thank you

  • @ughsirius
    @ughsirius4 жыл бұрын

    This was soooo helpful omg!! Thank you so much!

  • @YMMA2005
    @YMMA20052 жыл бұрын

    Amazing .. i watched several videos regarding this topic.. this is the best 👍🏽

  • @dr.ravshan_oncologist
    @dr.ravshan_oncologist7 ай бұрын

    best of the best, I was looking for answer to my question and found it here. Great job. Keep it up!!!

  • @pietndala7394
    @pietndala73942 жыл бұрын

    This is by far the best explanation I've ever came across. This is ideal platform to nurture future cardiologists and cardiothoracic surgeons.

  • @Snagrit

    @Snagrit

    10 ай бұрын

    Don't forget anaesthetists!

  • @mariamidzidziguri5882
    @mariamidzidziguri58825 ай бұрын

    Simply amazing! Thanks a lot!

  • @moriumakhter9803
    @moriumakhter9803 Жыл бұрын

    Thanks for such a detailed and comprehensive explanation...

  • @majdmuhannad7254
    @majdmuhannad72542 жыл бұрын

    this is an excellent video. Thank you so much!

  • @fatemenaghinasab9333
    @fatemenaghinasab93334 жыл бұрын

    you're a lifesaver sir thank you so much

  • @shaynemcgowan4049
    @shaynemcgowan40494 жыл бұрын

    You sir are brilliant and I thank you for sharing your knowledge

  • @beardedwhitecoat8925
    @beardedwhitecoat8925 Жыл бұрын

    As others have already said, excellent explanation. Hope you can post more videos and all is well.

  • @doctorkomari2327
    @doctorkomari23274 жыл бұрын

    very clear video, easy to follow with First Aid open to annotate :)

  • @Dr.abdulraffay
    @Dr.abdulraffay8 ай бұрын

    Absolutely amazing, liked and subscribed 💯

  • @rutulmodi4755
    @rutulmodi47553 жыл бұрын

    Amazing lecture sir, thanks for lectures. Want more and more lectures.

  • @aizazashraf5024
    @aizazashraf5024 Жыл бұрын

    This is GOLD !

  • @dhivyaraj4060
    @dhivyaraj40604 жыл бұрын

    tat was really simple and understndable ...thks a lot and luking for more videos like tis..

  • @emmelienschillern2394
    @emmelienschillern23942 жыл бұрын

    I finally understand it! Thank you very much :)

  • @RyanD808
    @RyanD8082 жыл бұрын

    Best explanation on KZread

  • @MuhammadJunaidAshraf
    @MuhammadJunaidAshraf4 жыл бұрын

    GREAT VIDEO!

  • @munojama9198
    @munojama91983 жыл бұрын

    Amazing lecture thanks. Plz continues this amazing lectures

  • @Naijagyal22
    @Naijagyal22 Жыл бұрын

    Incredible!

  • @GRABtheMD

    @GRABtheMD

    Жыл бұрын

    Thank you. Please share with your mates

  • @opelami
    @opelami2 жыл бұрын

    Absolutely brilliant

  • @olaebrhem5641
    @olaebrhem56412 жыл бұрын

    Thank you so much for this video it helped to make things easier and clearer thank you

  • @drnithyachandru
    @drnithyachandru2 жыл бұрын

    Really superb explanation.. thanks a lot for uploading this

  • @mahamotiv8100
    @mahamotiv8100Ай бұрын

    This was easily understandable. Thank you

  • @moizzazahid3766
    @moizzazahid3766 Жыл бұрын

    incredible video

  • @acetylcoa8559
    @acetylcoa85592 жыл бұрын

    what a explanation you got blessing and new subscriber added

  • @abdelhady4481
    @abdelhady44812 жыл бұрын

    Great video, very well explained. Make more videos if you can its helpful, Thanks!

  • @tayyabriz9701
    @tayyabriz97012 жыл бұрын

    You saved me bro Thanks a lot i am studying for step 1 and exam in about 3 months started doing these curves and i was very confused but your video really helped Thanks a lot for helping loads of Drs May Allah bless you Greetings and thanks from UK

  • @GRABtheMD

    @GRABtheMD

    2 жыл бұрын

    Thank you Tayyab for such kind words. These really mean a lot

  • @user-jx7zr1te4e
    @user-jx7zr1te4e4 ай бұрын

    Excellent Explanation ❤

  • @user-pl1nk3yr8p
    @user-pl1nk3yr8p2 жыл бұрын

    Extremely helpful video for medical school

  • @fatimamusawy5245
    @fatimamusawy52452 жыл бұрын

    Such an amazing explanation thanks 😊 alot

  • @sarahgaratli2182
    @sarahgaratli21824 жыл бұрын

    Thank you so so so so so much!!!!

  • @waleedahmed202
    @waleedahmed2024 жыл бұрын

    Excellent work brother

  • @llye2155
    @llye21553 жыл бұрын

    You are the best.....👍👍👍👍👍👍

  • @sharazahmed4812
    @sharazahmed48124 жыл бұрын

    Well done bro🏃🏼 keep it up

  • @Mindful_resting
    @Mindful_resting2 жыл бұрын

    Thank u sooo much for this awesome video

  • @hira791
    @hira791Күн бұрын

    better than BnB explanation for sure.

  • @Salam_1965
    @Salam_19652 жыл бұрын

    Outstanding teacher

  • @ayeshanawaz1344
    @ayeshanawaz13444 жыл бұрын

    THANKYOU SO MUCH 😭

  • @avivayash4857
    @avivayash48572 жыл бұрын

    amazing video!!!

  • @kpalm8977
    @kpalm89774 жыл бұрын

    Great job

  • @johnchan5228
    @johnchan52284 жыл бұрын

    you are a legend

  • @beratakn6007
    @beratakn6007 Жыл бұрын

    You’re the best

  • @studywitch
    @studywitch Жыл бұрын

    Thank you!

  • @jasmineothman3492
    @jasmineothman3492 Жыл бұрын

    Greattttttttt !!!! thanks a lot 👍👍🥀

  • @shaimakhalid6178
    @shaimakhalid61783 жыл бұрын

    thank you soooo much!!!💖

  • @Tika.B16
    @Tika.B16 Жыл бұрын

    thank you again

  • @mbk928
    @mbk9282 жыл бұрын

    thankkkks got the question right

  • @asantechiko3292
    @asantechiko32922 жыл бұрын

    excellent

  • @anistakesmedicine7464
    @anistakesmedicine74643 жыл бұрын

    Thank u sooo much bro 😍😍😍

  • @maicn4906
    @maicn49063 жыл бұрын

    Make sense Thanks 🌹

  • @dekiadortch9773
    @dekiadortch97735 жыл бұрын

    This video is amazing!!! looking forward to more content for anesthesia school

  • @GRABtheMD

    @GRABtheMD

    5 жыл бұрын

    I am glad to know you liked it. There's definitely more to come 👍

  • @nurukh9495
    @nurukh9495 Жыл бұрын

    thank you thank you thank you

  • @tahirraza671
    @tahirraza6715 жыл бұрын

    thanks...

  • @vanessaoliver9716
    @vanessaoliver97162 жыл бұрын

    wish i had such a professor🥺

  • @kamalx412
    @kamalx412 Жыл бұрын

    thank you

  • @mohammedalzainaltayebabdal2528
    @mohammedalzainaltayebabdal2528 Жыл бұрын

    Thank you very much These curves were nightmare for me 😂

  • @homeopathymedicos3849
    @homeopathymedicos38494 жыл бұрын

    Very understand

  • @aqibsattar9374
    @aqibsattar93742 жыл бұрын

    bravooo 🥰🥰

  • @silviachiaroni
    @silviachiaroni7 ай бұрын

    Thank you ❤

  • @silviachiaroni

    @silviachiaroni

    7 ай бұрын

    From Brazil

  • @oreman011
    @oreman0114 жыл бұрын

    this is super hot mega fire

  • @zarakhan7050
    @zarakhan7050 Жыл бұрын

    It's amazing. Rest of the systems please?

  • @mehdimesbah107
    @mehdimesbah1073 жыл бұрын

    it was amazing omg i learned by heartttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt

  • @phamquanghuymed
    @phamquanghuymed9 ай бұрын

    thankyoi

  • @user-ly8lw7ks7o
    @user-ly8lw7ks7o6 ай бұрын

    Hello, thank you for your clear explanation. I just didn't catch why the MSP doesn't change when the TPR increase or decrease. Can you help me with that please?

  • @omidmobargha3308
    @omidmobargha3308 Жыл бұрын

    Hi ! I'm an Italian student, sorry for my English. I know that pressure in peripheral veins is about 7mmHg and the pressure in right atrium is, physiologically, near 2mmHg. So the Delta P, responsible of venous return, is about 5mmHg. I also know that the right atrial pressure that blocks the VR is 7mmHg, in fact: DeltaP= 7-7=0 When we have a decrease in TPR, we have an increased VR. Doesn't this increase mean as an increase of the Q variable in Poseuille Law ? The poseuille law is: Q=DeltaP/R. If Q increases, we will see an increase in Delta P (if the R remains the same). Shouldn't this increase of Delta P also increase the pressure in right atrium which can block the venous return ? For example: if 7mmHg in peripheral veins turns into 10mmHg, shouldn't the right atrial pressure that block the venous return be 10mmHg ? So why all the blue lines in the graph ( 13:23 ) start at the same point ? Thank you so much I hope you can understand what I said

  • @rumaisahyaqoob2051
    @rumaisahyaqoob20517 ай бұрын

    Please make more vidoes on Usmle step 1

  • @RajKumar-tx5ln
    @RajKumar-tx5ln Жыл бұрын

    Please please upload more videos on other chapters

  • @raspberry765
    @raspberry7654 жыл бұрын

    Thank you so much for the video. I have a question about TPR and venous return. If we constrict the arterioles, why does VR drop? It takes slower due to resistance but the volume shouldn't change right?

  • @GRABtheMD

    @GRABtheMD

    4 жыл бұрын

    You are right. Slow speed means less blood per minute pouring into the heart. So reduced venous return per minute. However total volume of blood in the system (body) remains the same!

  • @raspberry765

    @raspberry765

    4 жыл бұрын

    GRAB the MD thank you so much!! The way you explained everything makes so much sense. May I also ask why does Right Atrial pressure drop with increased contractility?

  • @GRABtheMD

    @GRABtheMD

    4 жыл бұрын

    @@raspberry765 let's have a thought experiment. Let's see we REDUCE contractility, blood will start backing up in the heart chambers including the right atrium which will INCREASE RAP. Now think what will happen if we INCREASE contractility. Means the heart is pumping out most of the blood, the atria including RA will be empty most of the times hence the RAP goes down. I believe there's a more sophisticated explanation but this is how I think about it

  • @raspberry765

    @raspberry765

    4 жыл бұрын

    GRAB the MD bless your soul! Thank you so much, that clicked! And thank you for replying!

  • @mariumshaikh2145
    @mariumshaikh21453 жыл бұрын

    Hey, i dont understand why cardiac output first increases when right atrium pressure increases. Can you help me out

  • @GRABtheMD

    @GRABtheMD

    3 жыл бұрын

    Can you please elaborate on your question so I may explain it better

  • @medskool6765
    @medskool67653 жыл бұрын

    We know that fluid overload should not be given to pts with cardiac failure... However if we use these graphs to find the results of fuid overload on pts with decreased cardiac function it seems that there is not that much of a difference in the cardiac output. Also i dont under why in some starling curves of heart failure there is a plateau while in others there is a downward depression of cardiac function towards the end. I mean if we were to use the curve with downward depression with these vascular curves it would all make perfect sense for fluid overload in heart failure.

  • @rebeccaw8653
    @rebeccaw86533 жыл бұрын

    Hi! I have a question regarding the resistance, I don't understand why an increase in resistance would not cause a decrease in mean systemic filling pressure. If resistance is increased in the arterioles, that means that the amount of blood per min getting to the venous side of circulation would decrease right? You explained that this would decrease compliance of the veins so MSFP is maintained, but why would this then not work for, let's say the kidneys reabsorbed more water causing the blood volume to go up, then the veins could also increase their compliance right and maintain the same MSFP. or the opposite, you lose a lot of blood, so the veins then decrease compliance, and the MSFP is maintained.

  • @GRABtheMD

    @GRABtheMD

    3 жыл бұрын

    Smart questions! 1. In case of blood loss, the veins do decrease their compliance (get constricted) to push their blood into the arterial side (to be used for perfusion). 2. The kidneys and all the other hemodynamic systems do come into play in maintaining a balanced hemodynamic control, but we are not including all those in this discussion because it will get super complicated to understand. I hope this makes sense.

  • @Gabriel-yc1kx
    @Gabriel-yc1kx5 күн бұрын

    I dont understand how this stament is true: An increased blood volume (or venous tone) causes the cardiac output to increase and right atrial pressure to increase if the graph doesn't show increase in CO could someone help how to see increase of CO in the graph when venous return is changed?

  • @zhiying12
    @zhiying124 жыл бұрын

    Thank you so much for the video! I have a question though, how does TPR not affect the mean systemic pressure/right atrial pressure? the venous return is increased, meaning that the blood volume to the heart is increased, so why does the RAP remain the same?

  • @GRABtheMD

    @GRABtheMD

    4 жыл бұрын

    If you read the last sentence in First Aid under this section, it says in real life it's a mix of things. Everything can change everything. But for Step 1 we should stick to some rules. So unless you put more blood into the circulation, msp won't change. That's how I used to think when answering the questions.

  • @zhiying12

    @zhiying12

    4 жыл бұрын

    @@GRABtheMD thank you for replying!

  • @texastexas4541
    @texastexas4541 Жыл бұрын

    Very well presented. You must have spent a considerable amount of time to put it all together. Thank you! However, I would appreciate it if you could clarify one nagging question. At 14:25 , increasing TPR or decreasing TPR leads to an increase or decrease in CO at the same RAP and MSP. That means the driving pressure is the same but outcome is opposite. How do you explain an increase in CO or a decrease in CO at the same driving pressure (MSP-RAP)? Thanks in advance.

  • @Shantanu.Shandilya

    @Shantanu.Shandilya

    Жыл бұрын

    This is because on increasing TPR, afterload increases and CO also decreases. So, TPR causes both factors to change which wasn't the case in the first two cases.

  • @texastexas4541

    @texastexas4541

    Жыл бұрын

    @@Shantanu.Shandilya So, it is just the volume effect (dilation or constriction); same driving pressure but more flow vs less flow effect. Would it be correct to put it this way? Thanks.

  • @hira2349
    @hira23497 ай бұрын

    Effect of inotropy on VR ??

  • @ahmedatefkalash2379
    @ahmedatefkalash2379 Жыл бұрын

    What is the cause of the knee (flat portion) on the vascular function curve ? And if it’s because the veins collapse at negative right atrial pressure wouldn’t that render the venous return zero instead of a value near 7 liters/min ?

  • @GRABtheMD

    @GRABtheMD

    Жыл бұрын

    Good question. Let's set some ground rules. 1. There are no negative values on this graph. Both the axes start from zero. 2. The top flat portion (knee) on the vascular cure is the maximum amount of blood that can flow from veins into the right atrium. If you can trace from this flat portion vertically down, you will see that right atrial pressures are pretty low (but not below zero). At low right atrial pressure, the veins are pouring maximum of their blood into the right atrium. This portion is flat because venous return can't get higher than this physiologically. As we move to increasing right atrial pressures (towards right on x-axis), the RAP approaches MSF and the venous return keeps decreasing as shown by the downwards trend on vascular curve (starting at the end of the knee). Hope this helps!

  • @nasirjan6903
    @nasirjan69033 жыл бұрын

    You said after increasing TPR blood flows slowly to vein and blood flow decreases to right atrium. So why the msp doesn’t go down? By the way I really liked your explanation. .

  • @GRABtheMD

    @GRABtheMD

    3 жыл бұрын

    When the veins receive reduced blood, their compliance goes down. That results in increased pressure (P=V/C). This increasing pressure brings the msp back to normal. Hope this helps. Remember blood shift to arterial side reduces venous compliance. Blood shift to venous side increases venous compliance. These changes in compliance keep the msp in check. So the only way to change msp is either lose blood from the system. Or make vein constricted or relaxed.

  • @kareemcheezonrs
    @kareemcheezonrs3 жыл бұрын

    Can you explain why MSP does not change when you vasodilate or vasoconstrict? Thank you

  • @GRABtheMD

    @GRABtheMD

    3 жыл бұрын

    Vasodilation and vasoconstriction in this context is related to arteries. MSP is related to venous system that's why it's not altered by Vasodilation and vasoconstriction of arteries. Hope that helps

  • @usmancaptures
    @usmancaptures3 жыл бұрын

    What is difference bwetween Mean arterial pressure , Mean atrial pressure, Mean systemic pressure and Mean Circulatory Pressure. Kindly ANS...... Anyone