Syllabus Edition

First teaching 2023

First exams 2025

|

Measuring Pulse Rate: Skills (SL IB Biology)

Revision Note

Marlene

Author

Marlene

Expertise

Biology

Measuring Pulse Rate

  • The contraction of the ventricles forces a large volume of blood through the arteries, which expand to accommodate this
  • This can be felt as a pulse, especially in places where an artery is close to the skin surface or passes over a bone
    • For this reason, the carotid artery or radial artery can be used to measure pulse rate
      • The carotid artery runs down the side of the neck and a pulse can be felt just below the jaw
      • The radial artery passes over the wrist bones where a pulse can be felt just below the base of the thumb
  • A pulse can be taken as follows:
    • Place two fingers on the radial or carotid artery and gently compress the blood vessel
    • Count the number of pulses felt for 60 seconds
      • Alternatively, you could count for 30 seconds and multiply by 2
  • Do not use your thumb when taking a pulse, since it also has a pulse that can lead to inaccurate results
  • There are many digital devices that can also be used to determine pulse rate
    • These include data loggers, smartwatches or fitness bands
    • They scan the blood flow through the radial artery to measure pulse rate

Measuring pulse diagram

taking-pulse-measurement

The radial or carotid artery can be used to measure the pulse rate

Did this page help you?

Marlene

Author: Marlene

Marlene graduated from Stellenbosch University, South Africa, in 2002 with a degree in Biodiversity and Ecology. After completing a PGCE (Postgraduate certificate in education) in 2003 she taught high school Biology for over 10 years at various schools across South Africa before returning to Stellenbosch University in 2014 to obtain an Honours degree in Biological Sciences. With over 16 years of teaching experience, of which the past 3 years were spent teaching IGCSE and A level Biology, Marlene is passionate about Biology and making it more approachable to her students.