Your heart beats automatically thanks to its own built-in electrical... Show more
Physical Education
Combined Science
SociologySign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
3
0
Alice Crosby
13/12/2025
Physical Education
Cardiac conduction system
1 / 4
The Cardiac Conduction System
Think of your heart as having its own electrical wiring system that keeps it beating without you having to think about it. The cardiac conduction system consists of specialised cells in your heart walls that generate electrical impulses, making your heart myogenic - meaning it can contract on its own.
The electrical journey starts at the sinoatrial (SA) node, often called your heart's natural pacemaker. From there, the impulse travels through a specific pathway: it spreads through the atria (causing atrial systole), then reaches the atrioventricular (AV) node where there's a crucial 0.1-second delay.
This delay ensures your atria finish contracting before your ventricles start. The impulse then travels down the bundle of His in the septum, splits into left and right bundle branches, and finally spreads through Purkinje fibres throughout the ventricles, causing ventricular systole.
Key Point: The 0.1-second delay at the AV node is essential - without it, your atria and ventricles would contract simultaneously, making your heart much less efficient at pumping blood!
Neural Control of Heart Rate
During exercise, your heart rate needs to increase rapidly to supply working muscles with more oxygen - but how does this happen so quickly? The answer lies in neural control mechanisms involving your nervous system.
Your cardiac control centre in the medulla oblongata coordinates two competing systems: the sympathetic nervous system (which speeds up your heart) and the parasympathetic nervous system (which slows it down). When you're about to exercise - like taking a penalty in football - your body shows an anticipatory rise in heart rate.
This happens because sympathetic impulses increase whilst parasympathetic impulses decrease, both targeting the SA node. Your peripheral nervous system detects muscle movement (like your quadriceps extending) and sends this information via the central nervous system to your brain, which then signals the SA node to adjust heart rate accordingly.
Remember: Your heart rate can increase before you even start moving - that's your sympathetic nervous system preparing your body for action!
Chemical and Pressure Receptors
Your body has three types of clever sensors that constantly monitor what's happening and adjust your heart rate accordingly. Chemoreceptors in your carotid arteries and aortic arch act like chemical detectives, sensing changes in blood composition during exercise.
When you exercise, these chemoreceptors detect increased CO₂ levels in your bloodstream and signal your heart to beat faster. Meanwhile, baroreceptors monitor blood pressure changes and have a "set point" for normal pressure levels.
If blood pressure rises beyond this point, baroreceptors stretch and signal the medulla oblongata to decrease heart rate. Conversely, if pressure drops, the reduced stretch triggers an increase in heart rate. Interestingly, at the start of exercise, this set point increases so your heart rate doesn't slow down and hamper performance.
Proprioceptors in your muscles, tendons, and joints detect movement and body position. When they sense increased muscular activity, they send messages to increase heart rate via the sympathetic nervous system.
Quick Tip: Think of these receptors as your body's smart monitoring system - chemoreceptors check chemistry, baroreceptors check pressure, and proprioceptors check movement!
Receptor Summary and Response Patterns
Understanding how each receptor responds helps you grasp why your heart rate changes in different situations. The relationships are straightforward but crucial for your understanding of cardiovascular responses to exercise.
Chemoreceptors follow a simple pattern: increased CO₂ leads to increased heart rate. This makes perfect sense - more CO₂ means your body needs to work harder to remove waste and deliver fresh oxygen. Baroreceptors work oppositely to maintain balance: increased blood pressure triggers decreased heart rate to prevent dangerous pressure levels.
Proprioceptors respond directly to activity levels. More muscle movement signals increased heart rate, whilst reduced movement leads to decreased heart rate through parasympathetic stimulation of the SA node.
These three receptor types work together seamlessly, constantly adjusting your heart rate to match your body's needs whether you're resting, exercising, or recovering.
Exam Tip: Learn these three simple equations - they're frequently tested and help you understand the logic behind heart rate regulation during different activities!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in Physical Education
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Understanding the Cardiac Conduction System
Your heart beats automatically thanks to its own built-in electrical system - no conscious effort required! The cardiac conduction system controls your heartbeat through specialised cells that generate electrical impulses, whilst various receptors help adjust your heart rate during exercise... Show more
The Cardiac Conduction System
Think of your heart as having its own electrical wiring system that keeps it beating without you having to think about it. The cardiac conduction system consists of specialised cells in your heart walls that generate electrical impulses, making your heart myogenic - meaning it can contract on its own.
The electrical journey starts at the sinoatrial (SA) node, often called your heart's natural pacemaker. From there, the impulse travels through a specific pathway: it spreads through the atria (causing atrial systole), then reaches the atrioventricular (AV) node where there's a crucial 0.1-second delay.
This delay ensures your atria finish contracting before your ventricles start. The impulse then travels down the bundle of His in the septum, splits into left and right bundle branches, and finally spreads through Purkinje fibres throughout the ventricles, causing ventricular systole.
Key Point: The 0.1-second delay at the AV node is essential - without it, your atria and ventricles would contract simultaneously, making your heart much less efficient at pumping blood!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Neural Control of Heart Rate
During exercise, your heart rate needs to increase rapidly to supply working muscles with more oxygen - but how does this happen so quickly? The answer lies in neural control mechanisms involving your nervous system.
Your cardiac control centre in the medulla oblongata coordinates two competing systems: the sympathetic nervous system (which speeds up your heart) and the parasympathetic nervous system (which slows it down). When you're about to exercise - like taking a penalty in football - your body shows an anticipatory rise in heart rate.
This happens because sympathetic impulses increase whilst parasympathetic impulses decrease, both targeting the SA node. Your peripheral nervous system detects muscle movement (like your quadriceps extending) and sends this information via the central nervous system to your brain, which then signals the SA node to adjust heart rate accordingly.
Remember: Your heart rate can increase before you even start moving - that's your sympathetic nervous system preparing your body for action!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Chemical and Pressure Receptors
Your body has three types of clever sensors that constantly monitor what's happening and adjust your heart rate accordingly. Chemoreceptors in your carotid arteries and aortic arch act like chemical detectives, sensing changes in blood composition during exercise.
When you exercise, these chemoreceptors detect increased CO₂ levels in your bloodstream and signal your heart to beat faster. Meanwhile, baroreceptors monitor blood pressure changes and have a "set point" for normal pressure levels.
If blood pressure rises beyond this point, baroreceptors stretch and signal the medulla oblongata to decrease heart rate. Conversely, if pressure drops, the reduced stretch triggers an increase in heart rate. Interestingly, at the start of exercise, this set point increases so your heart rate doesn't slow down and hamper performance.
Proprioceptors in your muscles, tendons, and joints detect movement and body position. When they sense increased muscular activity, they send messages to increase heart rate via the sympathetic nervous system.
Quick Tip: Think of these receptors as your body's smart monitoring system - chemoreceptors check chemistry, baroreceptors check pressure, and proprioceptors check movement!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Receptor Summary and Response Patterns
Understanding how each receptor responds helps you grasp why your heart rate changes in different situations. The relationships are straightforward but crucial for your understanding of cardiovascular responses to exercise.
Chemoreceptors follow a simple pattern: increased CO₂ leads to increased heart rate. This makes perfect sense - more CO₂ means your body needs to work harder to remove waste and deliver fresh oxygen. Baroreceptors work oppositely to maintain balance: increased blood pressure triggers decreased heart rate to prevent dangerous pressure levels.
Proprioceptors respond directly to activity levels. More muscle movement signals increased heart rate, whilst reduced movement leads to decreased heart rate through parasympathetic stimulation of the SA node.
These three receptor types work together seamlessly, constantly adjusting your heart rate to match your body's needs whether you're resting, exercising, or recovering.
Exam Tip: Learn these three simple equations - they're frequently tested and help you understand the logic behind heart rate regulation during different activities!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
3
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Most popular content in Physical Education
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user