SWBAT identify the relationship between the respiratory and circulatory systems

Heart rate and respiration change with exertion. The changes correlate.

15 minutes

I begin this lesson by asking students to read an article about the cardiovascular system. I like this article because it is written in kid-friendly language and it describes both the structures and functions of the cardiovascular system and the link between the cardiovascular system and the respiratory system. Since we will explore the link between these two systems in today's lesson, I want my students to understand the basic relationship between their heart, blood, and lungs.

30 minutes

Next, I teach the students how to find their pulse. I ask students to place their pointer and middle fingers on the inside of their wrist directly under their thumb. I tell students to press down gently on their inner wrist until they can feel their pulse. If a student has a very difficult time locating their pulse in this way, I guide them to place their fingers on the outside of their neck, under their jawbone.

Once all students can locate their pulse, I ask students to count their resting pulse for thirty seconds. I ask students to multiply this number by two to find their pulse in beats per minute. I then ask students to record this number on their heart and respiration recording sheet. I then ask students to record their respiration rate in breaths per minute. A completed record sheet can be found here.

I repeat this process twice more with the students. The second pulse and respiration rates are recorded after the students do ten jumping jacks. The final pulse and respiration rates are recorded after vigorous exercise (my students ran in place for 1 minute or around our school track one time). A video of my students engaging is exercise and finding their pulse can be found here.

20 minutes

After collecting the data on their heart and respiration rates, I remind students that scientists must be able to record and share data with their peers. We brainstorm ways that scientists can share data with colleagues. I inform the students that they will use their data to write some conclusions and that they will represent their data using a bar graph. I provide students with the heart graph organizer. A completed example of a student's conclusion can be found here. A completed example of a student's graph can be found here.