Control of heart rate: Role of SAN & AVN in the cardiac cycle, Parasympathetic & sympathetic nerves

[@blythehenderson]

cramming for the paper at 9am. so simple, so streamlined. your videos are a godsend. thank you!!!

[@daisywells6608]

This channel has helped me so much, its been a lifesaver! Thank you for all of the videos you have released and the time you have spent to create them. You make the content much easier to understand and much more accessible. Youre saving my revision! Thank you :)

[@MissEstruchBiology]

Aww thank you for such a lovely message Daisy, it makes me so happy to know how much its helped you 😊 Fingers crossed for the rest of your revision and exams and really hope you achieve the grades you're aiming for.

[@katietaylor2804]

The most helpful channel❤️ I’m so glad I’ve discovered you. you are helping us more than you know

[@MissEstruchBiology]

I'm so glad the channel is helping you Katie😊😊

[@patienceomosigho]

Medulla oblagata - controls how quickly the wave of depolarisation is released from the SAN SAN - a tissue that releases waves of depolarisation that cause the atria to contract acts as a pacemaker Any impulses sent via the parasympathetic nervous system will trigger the SAN to slow down the release of waves of depolarisation,decreasing the heart rate.

[@marionmay7731]

Best A- Level Biology videos.

[@MissEstruchBiology]

Aww thank you!! Glad you think so.

[@heba1328]

Thank you! You explained it very well.

[@MissEstruchBiology]

Glad it was helpful! :D

[@mennaahmed4501]

You are amazing ! Thank you so much for your effort god bless you ❤️

[@MissEstruchBiology]

Thank you ☺ So happy to hear you like the content

[@bhekiebhekie9616]

THANKS FOR SUCH AMAZING EXPLANATIONS

[@MissEstruchBiology]

So happy you think so! Hope it had helped 😊

[@GastricIssuesFartman]

Hi Miss, the textbook mentions the binding of acetylcoline which binds to receptors on the SAN. Is mentioning this unnecessary?

[@mariaandthebear]

Thank you! This was very helpful :--)

[@MissEstruchBiology]

Really glad it helped 😊

[@finnerz9200]

when you mention pressure receptors stretch in response to blood pressure increase, is this same principle as pacinian corpuscle with stretch mediated sodium channels? Great video by the way🙂

[@sabriya5219]

Hi, in the CGP textbook it mentions acetylcholine and noradrenaline binding to receptors on the SAN. Is this necessary info for AQA?

[@shira7658]

Don’t need to know it

[@arinamohajeri9256]

thank you it was so good

[@MissEstruchBiology]

you're welcome 😊☺

[@talyastewart426]

How does noradrenaline play into this?

[@ash.orsmash]

pretty sure noradrenaline is a neurotransmitter that is released from the adrenal glands and travels through the sympathetic nerve in order to increase your heart rate

[@Ika-zg7vz]

Do u do OCR? If so, then for low bp/pH levels its the sympathetic ns so impulse travels from medulla to SAN (via sympathetic/accelerator nerve which releases noradrenaline which binds to SAN) to increase heart rate

[@AhhYdsaguiydqge]

Thank you so much Ms Estruch for your videos and notes they’ve helped me so much!🫶🏽

[@MissEstruchBiology]

So pleased they have helped you 😀

[@samsephton5788]

Another great video!! Just clarifying if the electrical impulses in the flow diagrams are still Waves Of Depolarisation?

[@samsephton5788]

And if so are they interchangeable? Thanks in advance!!

[@salemabrahaley2774]

i dont even do aqa but these vids are too good🤣

[@aizazeeshan9728]

depolarisation happens in tissues?

[@sunphlower3080]

How does heart rate affect blood pressure?

[@AM-hn7gj]

How does the left atrium contract at the same time as the right atrium if the SAN is only located in the right atrium?

[@arooj7329]

because the wave of electrical activity spreads across both atria

[@kamil_z91_72]

been looking at the specification and aqa approved workbooks and i cannot find anything on it so do i have to learn it?

[@MissEstruchBiology]

its in topic 6 AQA

[@harrybellis]

at the end in the part where receptors can change heart rate, you used pressurereceptors in some of the slides and chemoreceptors in others. Are these words interchangeable? Love these playlists by the way they have got me an A in my mock so far!

[@MissEstruchBiology]

Hey, they aren't interchangeable, but they are both receptors in this process. Chemoreceptors detect changes on pH (H+ ions) where as pressure receptors detect changes in blood pressure

[@anaymorjaria6447]

what about if it were an increased PH?

[@aqsakhan6946]

Increased ph means more co2 in blood so pressure is increased to remove the co2 from blood so you talk about chemoreceptors detecting the change in ph which sends impulses the medulla oblongata which sends even further impulses via the sympathetic pathway to the SAN to increase the heart rate

[@Ika-zg7vz]

@@aqsakhan6946 Almost correct! If high pH - LOW CO2, so same process just heart rate must now decreases so impulse travels down the Vagus nerve (paraympathetic ns) to SAN x

[@aqsakhan6946]

@@Ika-zg7vzoh yeh sorry confused high ph for low ph thanks

[@alanszewerniak2958]

is this a level?

[@MissEstruchBiology]

yes 😊

[@ordinarykaycee]

Just the apex

[@rejoiceamieghemen4638]

What are your bank details? YT cannot be paying you enough for your service !

[@MissEstruchBiology]

😂😂 I accept Taylor Dwift Eras tour tickets