How is the pulse rate controlled by the medulla and the adrenal glands?
This simple classroom activity is worksheet based with an interactive whiteboard presentation. It will help students to make sense of the links between the medulla oblongata, the adrenal glands and the pacemaker of the heart. Students will understand the key differences between the nervous system and hormones, they will practice remembering the main biological concepts and create a sheet of revision notes.
How does blood flow through the heart?
How is the rate of the heart's beating controlled?
Look at the diagram below and try to describe each step of how the blood flows through the heart.
Activity 1 - Worksheet activity.
Read the bullet points on the worksheet which summarise the key details of the control of heart beat. Highlighting a few key words in each bullet point to help you remember it later.
Use these phrases as labels to annotate the diagram on the back of the sheet. Control of heart rate worksheet
Memorize the annotations as whole points.
Activity 2 - Think / Pair / Share
Think for a minute or two about what you would say if someone asked you to explain the diagram on the worksheet. Run through the explanation in your head. Ask for any clarifications you need and make a note of answers.
Pair up with someone in the class for just five minutes and take turns to say your explanation out loud.
Offer suggestions of improvements to your partner.
Share your explanation with the whole class - at the whiteboard if you are confident enough.
Activity 3 - IB Style questions
Answer these IB style heart rate questions. Remember to use the new details which you have learnt.
Extension - Video animation of a beating heart in the human body.
This page can be projected on the whiteboard during the lesson.
The central part of the activity is a printable worksheet, there is a starter activity, an IB style question and a video animation which could be used as an extension.
- The mygenic nature of heartbeat
- The control of heartbeat by the medulla using nerves
- The hormonal control of heartbear by the adrenal glands
A possible lesson plan
Starter (10 minutes)
- Students get out notes and consider how the body might control the rate of heart beat.
- Plenary 'discussion' of the myogenic nature of the heart beat and a recap of the structure of the heart.
Main (30 minutes)
- Students read through the points on the worksheet, identify any points they don't understand and look for clarification of any confusion.
- Students label the diagram on the reverse side of the worksheet.
Encourage the students to remember the labels as much as possible.
- Think Pair Share activity will help build student confidence in their understanding of the control of heartbeat
One or two students can share their explanations with the whole class.
End (20 minutes)
- Students attempt the IB style questions
Students could mark these using the model answer sheet.
- IB style heart rate model answers
- Show the video to the whole class, or individual students can watch the final animation while others complete the questions.