Cardiac Output & Venous Return Curves

Cardiac Output & Venous Return Curves | 7.08 CVS PHYSIOLOGY

Рет қаралды 82,087

5 жыл бұрын

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: 192

@jaredcovers218 3 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 2 жыл бұрын

agree completely

@AestheticMEDICO 2 жыл бұрын

agree

@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 2 жыл бұрын

agree 👍🏼

@sililly1379 5 жыл бұрын

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

@733-vandanaharitha5 4 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 4 жыл бұрын

Good to know it's helping 😊

@mrmuppetdzn4421 2 жыл бұрын

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

@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!

@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

@ilsakhan9631 4 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!!!!!

@krsjhn01 4 жыл бұрын

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

@softcloud3949 2 жыл бұрын

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

@ayushisachan2549 Жыл бұрын

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

@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

@MrAndyroni 2 жыл бұрын

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

@MrCOOKIEMONSTA4 4 ай бұрын

Absolutely amazing video!!! Compliments and much appreciated

@kalpanagosai1709 2 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 2 жыл бұрын

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

@pietndala7394 2 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 11 ай бұрын

Don't forget anaesthetists!

@coolkitty154 2 жыл бұрын

Incredible explanation, thank you!

@lryuzaki8018 Жыл бұрын

You deserve 30000000 subs! thank you!

@kritikasriram6518 6 ай бұрын

Great video with crystal clear explanations, thank you

@utkarshsodyssey903 4 жыл бұрын

Brilliant illustration 🎉👍🏻 more videos please!!

@YMMA2005 2 жыл бұрын

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

@coreycarney4776 4 жыл бұрын

This was so helpful! Thank you!!!

@dr.ravshan_oncologist 8 ай бұрын

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

@majdmuhannad7254 3 жыл бұрын

this is an excellent video. Thank you so much!

@fatemenaghinasab9333 4 жыл бұрын

you're a lifesaver sir thank you so much

@ughsirius 4 жыл бұрын

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

@shaynemcgowan4049 4 жыл бұрын

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

@divaroshan3797 3 жыл бұрын

This video is a jackpot man!

@beardedwhitecoat8925 2 жыл бұрын

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

@moriumakhter9803 2 жыл бұрын

Thanks for such a detailed and comprehensive explanation...

@mariamidzidziguri5882 6 ай бұрын

Simply amazing! Thanks a lot!

@doctorkomari2327 4 жыл бұрын

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

@dhivyaraj4060 4 жыл бұрын

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

@aizazashraf5024 2 жыл бұрын

This is GOLD !

@rutulmodi4755 3 жыл бұрын

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

@olaebrhem5641 2 жыл бұрын

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

@emmelienschillern2394 2 жыл бұрын

I finally understand it! Thank you very much :)

@mahamotiv8100 2 ай бұрын

This was easily understandable. Thank you

@Dr.abdulraffay 9 ай бұрын

Absolutely amazing, liked and subscribed 💯

@munojama9198 3 жыл бұрын

Amazing lecture thanks. Plz continues this amazing lectures

@drnithyachandru 2 жыл бұрын

Really superb explanation.. thanks a lot for uploading this

@abdelhady4481 2 жыл бұрын

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

@RyanD808 2 жыл бұрын

Best explanation on KZfaq

@acetylcoa8559 2 жыл бұрын

what a explanation you got blessing and new subscriber added

@moizzazahid3766 Жыл бұрын

incredible video

@user-jx7zr1te4e 5 ай бұрын

Excellent Explanation ❤

@MuhammadJunaidAshraf 4 жыл бұрын

GREAT VIDEO!

@fatimamusawy5245 2 жыл бұрын

Such an amazing explanation thanks 😊 alot

@opelami 2 жыл бұрын

Absolutely brilliant

@Naijagyal22 Жыл бұрын

Incredible!

@GRABtheMD Жыл бұрын

Thank you. Please share with your mates

@user-pl1nk3yr8p 2 жыл бұрын

Extremely helpful video for medical school

@sarahgaratli2182 4 жыл бұрын

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

@tayyabriz9701 2 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 2 жыл бұрын

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

@studywitch Жыл бұрын

Thank you!

@Mindful_resting 2 жыл бұрын

Thank u sooo much for this awesome video

@beratakn6007 Жыл бұрын

You’re the best

@llye2155 3 жыл бұрын

You are the best.....👍👍👍👍👍👍

@waleedahmed202 4 жыл бұрын

Excellent work brother

@ayeshanawaz1344 4 жыл бұрын

THANKYOU SO MUCH 😭

@sharazahmed4812 4 жыл бұрын

Well done bro🏃🏼 keep it up

@jasmineothman3492 Жыл бұрын

Greattttttttt !!!! thanks a lot 👍👍🥀

@johnchan5228 4 жыл бұрын

you are a legend

@avivayash4857 2 жыл бұрын

amazing video!!!

@kpalm8977 4 жыл бұрын

Great job

@hira791 25 күн бұрын

better than BnB explanation for sure.

@nurukh9495 2 жыл бұрын

thank you thank you thank you

@Sam_1964 2 жыл бұрын

Outstanding teacher

@Tika.B16 Жыл бұрын

thank you again

@kamalx412 Жыл бұрын

thank you

@shaimakhalid6178 3 жыл бұрын

thank you soooo much!!!💖

@mbk928 2 жыл бұрын

thankkkks got the question right

@mediziner4283 21 күн бұрын

thankyou so much

@aqibsattar9374 2 жыл бұрын

bravooo 🥰🥰

@asantechiko3292 2 жыл бұрын

excellent

@maicn4906 3 жыл бұрын

Make sense Thanks 🌹

@vanessaoliver9716 2 жыл бұрын

wish i had such a professor🥺

@anistakesmedicine7464 4 жыл бұрын

Thank u sooo much bro 😍😍😍

@dekiadortch9773 5 жыл бұрын

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

@GRABtheMD 5 жыл бұрын

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

@user-ly8lw7ks7o 6 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?

@silviachiaroni 8 ай бұрын

Thank you ❤

@silviachiaroni 8 ай бұрын

From Brazil

@mohammedalzainaltayebabdal2528 Жыл бұрын

Thank you very much These curves were nightmare for me 😂

@tahirraza671 5 жыл бұрын

thanks...

@homeopathymedicos3849 4 жыл бұрын

Very understand

@phamquanghuymed 10 ай бұрын

thankyoi

@mehdimesbah107 3 жыл бұрын

it was amazing omg i learned by heartttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt

@oreman011 4 жыл бұрын

this is super hot mega fire

@zarakhan7050 Жыл бұрын

It's amazing. Rest of the systems please?

@zhiying12 4 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 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 4 жыл бұрын

@@GRABtheMD thank you for replying!

@raspberry765 4 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 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 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 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 4 жыл бұрын

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

@nazninsharmi4098 4 жыл бұрын

Can anyone explain me why pos/neg inotrophy doesnt alter the vascular function curve as the curve depends on Cardiac output and the curve of CO changes in pos/neg inotrophy?

@ShahsawarM Жыл бұрын

MSFP represents the pressure generated by elastic recoil in the systemic circulation during a no-flow state. When we bring cardiac output to the discussion, it means we are not talking about a no-flow state anymore. MSP depends upon the elastic recoil of veins (put more blood into the veins from outside => veins will stretch out more => veins will recoil back with force => increase MSP). Hope this makes sense Answer copied from GRAB the MD

@hira2349 8 ай бұрын

Effect of inotropy on VR ??

@omidmobargha3308 2 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

@rebeccaw8653 3 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 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.

@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 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!

@kareemcheezonrs 3 жыл бұрын

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

@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

@shahranc5697 3 жыл бұрын

can someone explain if the cardiac output changes with changes in the blood volume(second graph)? it should decrease with a decrease in blood volume or venous tone,right?

@GRABtheMD 3 жыл бұрын

You are right. It does decrease

@shahranc5697 3 жыл бұрын

@@GRABtheMD okay,thank you,great video,very helpful

@mariumshaikh2145 3 жыл бұрын

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

@GRABtheMD 3 жыл бұрын

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

@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 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 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.

@rumaisahyaqoob2051 8 ай бұрын

Please make more vidoes on Usmle step 1

@medskool6765 3 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.

@biprajitroy209 5 жыл бұрын

Why MSP and RAP remain same even if you increase or decrease TPR?

@GRABtheMD 5 жыл бұрын

MSP and RAP change when we increase or decrease the amount of blood in the system. Changing tpr does not affect the volume of blood in the system. Volume stays the same. We only constrict or relax the arterioles when we change the tpr.