The Cardiac Cycle, Animation
Вставка
- Опубліковано 21 вер 2024
- (USMLE topics, cardiology) Phases of the cardiac cycle. The Wiggers diagram explained.
Purchase a license to download a non-watermarked copy of this video on AlilaMedicalMedia(dot)com
©Alila Medical Media. All rights reserved.
Voice by: Sue Stern.
The cycle is initiated with the firing of the SA node that stimulates the atria to depolarize. This is represented by the P-wave on the ECG. Atrial contraction starts shortly after the P-wave begins, and causes the pressure within the atria to increase, FORCING blood into the ventricles. Atrial contraction, however, only accounts for a FRACTION of ventricular filling, because at this point, the ventricles are ALREADY almost full due to PASSIVE blood flow DOWN the ventricles through the OPEN AV valves.
As atrial contraction completes, atrial pressure begins to FALL, REVERSING the pressure gradient across the AV valves, causing them to CLOSE. The closing of the AV valves produces the first heart sound, S1, and marks the beginning of SYSTOLE. At this point, ventricular depolarization, represented by the QRS complex, is half way through, and the ventricles start to contract, RAPIDLY building UP pressures inside the ventricles. For a moment, however, the semilunar valves remain closed, and the ventricles contract within a CLOSED space. This phase is referred to as isovolumetric contraction, because NO blood is ejected and ventricular volume is UN-changed.
Ventricular ejection starts when ventricular pressures EXCEED the pressures within the aorta and pulmonary artery; the aortic and pulmonic valves OPEN and blood is EJECTED out of the ventricles. This is the RAPID ejection phase.
As ventricular repolarization, reflected by the T-wave, begins, ventricular pressure starts to FALL and the force of ejection is REDUCED.
When ventricular pressures drop BELOW aortic and pulmonary pressures, the semilunar valves CLOSE, marking the end of systole and beginning of diastole. Closure of semilunar valves produces the second heart sound, S2.
The first part of diastole is, again, isovolumetric, as the ventricles relax with ALL valves CLOSED. Ventricular pressure drops RAPIDLY but their volumes remain UNchanged.
Meanwhile, the atria are being filled with blood and atrial pressures RISE slowly. Ventricular FILLING starts when ventricular pressures drop BELOW atrial pressures, causing the AV valve to open, allowing blood to flow DOWN the ventricles PASSIVELY.
All images/videos by Alila Medical Media are for information purposes ONLY and are NOT intended to replace professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare provider with any questions you may have regarding a medical condition.
Love this video? Check out our course "Cardiovascular Physiology" made entirely with videos like this (no watermark, no ads):
Students, click here: www.alilaacademy.com/courses/cardiovascular-physiology-for-students
Teachers, click here: www.alilaacademy.com/courses/cardiovascular-physiology-for-teachers
NEW: Now you can also get access to our courses with our UA-cam channel membership (Academy Access levels)
4 minutes taught me what a 1 hour lecture couldn't... thank you!
Lol
Really
Really lol
Lmao ikr
But I still don't understand
The cardiac cycle refers to the sequence of events that occur and repeat with every heart beat. It can be divided into 2 major phases, Systole and Diastole. Each of which subdivides into several smaller phases. Systole and diastole refer to ventricular contraction and relaxation respectively.
Reminders:
- blood flows from higher to lower pressure
- contraction increases the pressure within the chamber while relaxation lowers the pressure
- Av valves open when atrial pressure are hogher than ventricular pressure and close when the pressure gradient is reversed
- Similarly semilunar valves open when ventricular presures are higher than aortic pulmonary pressures and close when the reverse is true.
Phase 1 atrial depo/contraction
Phase 2 iso. Contrction
Phase 3 rapid ejection
Phase 4 reduced ejection
Phase 5 iso. Relaxation
Phase 6 ventricular filling
The cycle is initiated when the firing of the SA node that stimulates the atria to depolarize. This is represented by the P wave in the ECG. Atrial contraction starts shortly after the P wave begins and causes the pressure within the atria to increase forcing blood into the ventricles. Atrial contraction however only accounts for a fraction of ventricular filling because at this point the ventricles are already almost full due to passive blood flow down the ventricles thru the open av valves. As atrial contraction completes, atrial pressure begins to fall reversing the pressure gradient across the av valves causing them to close. The closing if the av valves produces the first heart sound S1 and marks the beginning of systole. At this point, ventricular depolarization represented by rhe QRS complex is halfway thru and the ventricles contract rapidly building up pressures inside the ventricles. For a moment however the semilunar valves remain closed and the ventricles contract within a closed space. This phase is refered to ISOVOLUMETRIC CONTRACTION because no blood is ejected and ventriclular volume is unchanged. Ventricular EJECTION starts when ventricular pressure exceed the pressure within the aorta and pulmonary artery. The aortic and pulmonic valves open and blood is ejected out of the ventricles. This is the RAPID EJECTION PHASE. As ventricular REPOLARIZATION reflected by the T wave begins, ventricular pressure starts to fall and the force of ejection is reduced. When ventricular pressure drop below aortic and pulmonary pressures, the semilunar valves closed marking the ends of systole and beginning of diastole. Closure of semilunar valves produces the second heart sound S2.
The first part of diastole is again isovolumetric relaxation as the ventricles relax with all the valves closed, ventricular pressure drops rapidly but their volumes remains unchanged. Meanwhile the atrium being filled with blood atrial pressure rise slowly, ventricular filling starts when ventricular pressure drops below atrial pressures causing av valves to open allowing blood to flow down the ventricles passively. The atrial contract to finish the filling phase and the cycle repeats itself.
thank you
THANK YOU FOR THIS!
thanks for thisssssss!!!!!!!!!!!
THANK YOU SM!!!
Really appreciated this summary
This video just compiled an entire 100+ slides, 6 individual 10+ min videos, into a 5min animation. ANIMATIONS ARE SO UNDERRATED. you need to see the animation paired up next to a graph in order to grasp and apply the full concept of the Cardiac cycle. I've been looking for a video like this.
same here 👍
ABSOLUTELY! AS AN AUDIO-VISUAL LEARNER, THIS IS DEFS AN EXTREMELY HELPFUL TECHNIQUE
Where are the animations?
For those of you reading this comment, it's okay, it's normal to feel lonely sometimes, if you're going through tough times, keep trying, but never give up,
one second takes months to understand
u got to think multilayer ,as of the electric chimical and mechanical events,then moving on a time lime everything becomes clearer
poetic way to look at. Likey.
takes months to understand, yet you have to do it in one week XP
0.8 sec more accurately😛
the 480,000 views were just the 6k thumbs up folk watching 80,000 times on repeat
As a medical student, this took me a while to understand. But after practice and time and time of coming back to this video I would have to say this is the BEST video out there on the cardiac cycle, EKG, systole, diastole etc. It's 100% spot on.
When a 4 min video in a foreign language (foreign because I'm studying this in German) explains it a 100 times better than expensive text books over an entire chapter...
Lol, honestly, UA-cam teaches better then books, sometimes, plus, its cost free.
An welcher Uni bist du
For real tho lol
If you're searching for videos that explain the CARDIAC CYCLE - STOP! LOOK NO FURTHER! This is THE BEST VIDEO on UA-cam. Thank you!!!!!
THIS IS SUCH A LIFE SAVER. THANK YOU. alot of the videos dumb down the explanations and dont give you how they relate to the ecg recordings
love it.
Amazing!
I never realised the sound of the heartbeat was actually the slamming shut of the valves. I always had assumed that somehow the muscle contractions made the sound directly.
Me too man 🤣
a non-understandable 90 mins lecture reduced into an amazing 4 mins video!!!
god bless you, you help medical students around the whole world
Abdallah Hariri are you a medical student ? of which university
@@khalidkingkhankhan6782
Yes I'm, Misr University For Sience And Technology (Egypt)
amazing. 15 pages of knowledge in 4:10 minutes. THANKS.
you literally changed my life in just 4 minutes i cannot thank you enough
This is incredible. Easily the shortest yet most comprehensive overview of the cardiac cycle I have found yet. Textbooks make it seem more convoluted than it actually is.
I, as a physiologist, found these medical education videos from Alila Medical Media very simple, informative and well explained in almost every clinical perspective.
Thank you Mr. Prakash
For the past couple weeks I couldn't get anyone to successfully explaine systole and diastole.. within the first 20 seconds of this video I finally feel confident about the entire process! Thanks for filling in the gaps and sharing this. Great video!
This is probably one of the best, most informative videos on human anatomy I have ever watched.
I'm 14, taking gifted bio classes. this helped me a lot because I didn't understand anything in class. very clearly explained
Best video ever. Kudos to creators. You saved millions of med students. Thank you.
This video is presented awesomely thank u , though lets remember that there is also a " Dicrotic Notch " seen in the aortic pressure right in there while the pressure in the ventricles is falling as they relax , and this notch is there because once the aortic valve closes ( to prevent backflow ) some of this blood that wants to flow back into the ventricles from the aorta , bumps into the closed aortic valve and bounces back .
Clearer than the two hours worth of lecture videos I had to watch to get this information! Thank you!
Thank you for all your medical videos it has been very helpful instead of reading a 27 pages of a Text book 4 mins has done it all
Thank you once again ❤❤❤
Made wiggers diagram so easy. This video was the best one so far❤
amazingly putting all the chart together at same time comparing with the heart on the side that really helps us to have a more complete pic of what's really going on at diff stages.
Thank you!
From a Music Ed major that has to take Life Science to graduate. Science is like learning French for me 😩 but this really helped! 😃❤
Hallo
i just spent like 5 hours figuring this out when i could've just watched this video, fml
in addition i kept getting confused when i would see AV valve(s) and think they were referring to the aortic semilunar valve and was about to cry
THANK YOU!! months of half-understanding fixed in under 5 minutes.
I remember watching thia video in the past years just to know the phases of the heart cycle. i returned once again to see how its denoted on the EKG. just to say its lovely how so much information and diversity is given in 1 Video
You were so explicit and accurate
Especially at the valves
Thank you
Big 👍🏽
Woooowwww,best explain in world's about the "Cardiac cycle"😍😌😔...
Greetings from a medical student in Iraq🇮🇶😍💪🏽
THANK YOU
sincerely,
stressed out dental student :')
Me too By the why which country u are from
Same here sis ):
Alexandria Talley same.
Same here guys :")
saaaame :D
The way presentation the so inspiring and understandable...made basics strong...and unlike other videos proper events in a cyclic way are explained...it's no less than a life saver
This is incredible
Thank you
You just simplified the Wiggers Diagram
Any student here taking a Physiology course and learning Chapter 13 of The Heart? The lecture with slides and photos is not enough. This puts everything in less than 5 minutes from a 4 hour lecture.
That graph is the bane of my existence
This vedio was worth watching.....I mean....entire thing in just 4 mins......That's what we need!!Loved it!
Thank you for explaining it step by step. It's really helpful. I saw this diagram on books but haven't got any information out of it. But now I can see how useful this diagram is.
This video deserves 10M views! 💓 Precise! On spot! Perfect!
Thank you SO MUCH ! I have my final exams soon and i had troubles to understand this part so THIS IS AMAZING ! THANKS ! 😍
Thank you so much, A clear explaination. 4 minutes video for 1 hour lesson taught me perfectly
Currently a Paramedic going through ADN school to become an RN. Cardiology is a weak point for me but this video helps a ton. Thanks
Thank you so much... this has made my fundamentals very strong. Once again, really appreciated!
I'm glad I clicked this video FIRST. Helped me a lot!
Amazing..!!
Excellently explained in shortest time possible
Thanx😊
At first i studied from my textbook.. Than... Watched almost 7 to 8 videos of so long durations... But these 4 minutes changed my mind and my mood as i was so furious and was about to cry... ❤ thanks to this video for making my heartbeat normal once again 😍haaaaaaaahhhh
your videos are the best and are better than thousand lectures
Why is this so hard to learn? 😭😭😭
Its easy if u r not a kid
Karan Choudhary did u understand
Because there are so many steps and many details that are broken into smaller steps.
But memory is improved with fish oil or krill oil, magnesium, niacin (no flush) and vitamin D. I found I didn't need to repeat as much when I was on my brain supplements.
whisperingsage how do you take these supplements on a daily basis?
One of the best videos I have came across
Thank you so much. This helped me more than any lecture or textbook
Thank youuu sooooo much dear.. yesterday I have planned to refuse this topic..bcz it's very hard to understand.i didn't understand anything from this complex cycle.. now i am ok with this. Thank you
Thank you, I'm taking pathophysiology and needed a refresher ♥️
Thank you for summarizing a 6 hour lecture ❤❤
best cardiac cycle video in the internet
i actually used a stopwatch to see,what time a cycle required and it actually took 0.8 sec ,the time our heart takes.Seriously nice easter egg @alilamedicalMedia
:) glad you noticed, we always try to be as accurate as possible :)
Give this channel a award just for this video!✨
Thanku so much it help me so much I learned quickly from here and today is my final exam:)
This video is going to be the video that makes me pass my exam
Thank you so much for helping me teach human physiology to my students!
This is soooooo helpful before exams tomorrow, thank you!
I was stuck in this topic for an hour and you taught me that in minutes..... thank you so much...!!!
I always have a confusion regarding cardiac cycle. But this video helped me. Thank u🙏
You’re welcome 😊
Thank you, very helpful ❤️❤️
Articulate and explained slowly. Excellent graphics
av valves open when atrial pressue>ventrical pressures
slv valves open when ventricular pressure> aortic/ pulmonary pressure
*Atrial depolarization phase 1:*
1. cycle initiated by SA node *firing*
2. atria depolarize
*(P)*
3. atrial contraction (atria pressure increase)
4. blood into ventricles
4. ventricles filled by blood through av valves open(straight line in ventricle volume)
atrial contraction complete
5. atrial pressure fall
6. Pressure gradient reverse in av valves and they close (first heart sound) (s1)
*S1*
*IsoVolumeTeric CONTRACTION phase 2:* (no blood ejected and ventricular volume unchanged)
7. Ventricular depolarization (QRS complex) halfway through
8. Ventricles start to contract
*RAPID ejection phase 3:*
9. ventricular ejection
when ventricular pressures exceed aorta and pulmonary artery pressures and
10. pulmonic valves open
11. blood ejected out of ventricles
*REDUCED ejection phase 4:*
12.ventricular repolarization *(T)*
13. vp fall
14. ejection force reduced
15. vp below aortic and pulmonary pressure
16. SLV close
*IsoVolumeTeric RELAXATION phase 5:*
*S2*
IsoVolumeTeric= Ventricles relaxed, valves closed
17. ventricular pressure drop, ventricular volume unchanged
18. atria being filled with blood and atrial pressure rise
*Ventricular filling phase 6:*
19. ventricular filling start when ap>vp
20. AV Valve open
21. blood down ventricles
22. atria contract (to finish filling phase)
23. repeat
As a Respiratory Therapist student, this REALLY helped out with grasping the visual understanding of blood flow. I've been trying to wrap my brain around the individual heart stages. Thank you so much!!!
Can you do a video for preload, afterload, and cardiac output?
really good video, very condensed but otherwise accurate and easy to understand
Ohh girl uhh explained each thing reallyyyy clearly thank you so much all concepts are visual now❤️ love from INDIA❤️
Very nice. A hard topic descrived in only 4 minutes. Pls make a video on hemodyamic.(CO/VR)
WOW amazing video. You saved me from going crazy on cardiac physiology
Thank u explaining the complex process in a simple way
Happy to help
Watching for my neet mds.... U are really amazing
I'm watching this for my A levels and I wish anyone told us about it before.. Amazing video
Very good explanation...we couldn't understand it even in our 1 hrs class lecture ❤️❤️
Thank you! Seeing ALL of this at the same time helped me SO much!
Excellent explanation. Thank you
God loves you and he wants to save everyone ❤️
I don’t know how to thank you, very well explanation with the heart picture and animation of the cycle with the ECG diagram! Thank you sooooo much
Excellently explained! And the visuals are so easy to follow! Great job
Every second is important in this video!
this is too good
make videos on working of ear eye and kidney also
Omg thank you so much
Perfectly explained in just 4 minutes
Really wonderful video. I watched many videos about cardiac cycle but not one was able to illustrate it in a comprehensive way like this video. You've earned my subscription and like 👍
All I can say is God bless you ma'am!. Thank you
Wow 🤩you guys are doing so cool ✨ the animation and the explanation is so unique and makes the lesson so much simple thanks 🤗
better explanation than my A&P II professor
This channel is GOLD!!
This Cardiology playlist is awesome! Thank you
Fantastic approach. Highly appreciable.
Thank you so much for nice animated explanation in easy way..🙏🏻🙏🏻😊❤️
thnk u, i've a presentation about tht and this helped me sm
Hello, I have a presentation about this topic, can you help me by sending some documents that you made previously for your presentation...
Plz.
🙏🙏🙏🙏
I rarely write comments, but this 4 minute video made me do it! So good!😀❤
It’s funny how it takes to learn all those processes while it takes them a second. ;)
I LOVE THIS CHANNEL SO MUCH 🤧😍
liked subscribed and shared this video because this is the least i can do to show my gratitude. thank you for saving the day of us all.
Excellent video. I'm just too tired right now. Still have a week till the test, I'll be back.
Aced Systemic Physiology!! I was actually very happy when heart questions showed up on the exam and final. Thank you!
Lucky you. Mine is Saturday..AHHHHHHHHHHHH
Thanks a lot!!
My teacher explain this for 40 minutes but still couldn't get the gist.
That was awesome! I really appreciate what you do because it really helps me to understand
Seeing people commenting on how good this video is and I still don’t know what the hell is going on. Am I dumb?
Best video on cardiac cycle ever by a distance