Lab – The Effects of External Stimuli on Heart Rate and Blood Pressure
Adapted from Course Content for SBI 4U from KPR eLearning
In this lab you will be investigation the effects of external stimuli on heart rate and blood pressure.
Pre-Lab Activity 1 – Understanding the Effects of Stimulants and Depressants on the Body
Read the links provided in the Resources section at the bottom of the lab web page.
These links will help to inform your prediction and hypothesis for this lab.
Pre-Lab Activity 2 – Understanding How to Measure Heart Rate (HR) and Blood Pressure (BP)
1.
Begin the lab activity.
2.
Proceed through the lab to learn how to measure heart rate and blood pressure.
Answer the following questions as you proceed: a.
Why does a stethoscope need two different structures for detecting sound? b.
What is the calculated HR for the example? c.
What is systolic pressure? Is it the numerator or the denominator? d.
What is diastolic pressure? Is it the numerator or the denominator? e.
Briefly describe how BP is measured. f.
What is the BP of the subject shown?
Pre-Lab Activity 3 – Predictions and Hypothesis/Observation Table
Formulate predictions and hypotheses for the following situations: a.
John’s heart rate and blood pressure relative to resting heart rate and blood pressure after hearing a ghost. b.
John’s heart rate and blood pressure relative to resting heart rate and blood pressure after climbing the stairs in the CN Tower. c.
John’s heart rate and blood pressure relative to resting heart rate and blood pressure after drinking some alcohol.
Based on the predictions and hypotheses you formulated, create an appropriate observation chart to use when completing the lab.
At this point, please show your pre-lab activity completion to Mrs. Petrany before proceeding with the remainder of the lab.

Post Lab Activity – Complete the Following Discussion Questions as part of your formal lab report. Do not number the questions within your discussion. Integrate your answers into proper paragraphs within your report.
1.
Why is it important to take the resting heart rate and blood pressure of the subject before beginning the experiment?
2.
Explain the experiment in terms of stimulus and response. What is the stimulus and the response in each situation with John?
3.
How is the heart restored to homeostasis in each situation?
4.
Identify the part of the autonomic nervous system and any neurotransmitters or hormones you have researched that are involved in this laboratory simulation.
5.
Predict and hypothesize what you think drinking 5 cups of coffee would do to John’s blood pressure and pulse rate.
6.
Caffeine is a stimulant. Explain this term and the effect of caffeine on the nervous system.
How does it affect the endocrine system and excretory system?
7.
How is homeostasis restored after taking caffeine?
8.
Why do you suppose that drinking before driving is prohibited in Ontario? Explain the physiological effects of alcohol and how it affects the nervous system.
The Lab Report – this is a formal lab report. Please follow the 4U General Lab Report Outline.
NOTE: You do not need a Materials and Procedures section for this lab.
Mark Breakdown
Title Page /5
Introduction /15
Results /5
Discussion /10
Conclusions /10
References /5
Total = ______/50 marks
This assignment is due Tuesday, May 28 at 11:59 pm. You may hand in your lab using ONE of
the following methods:
1.
As an attachment through e-mail: tracy_petrany@kprdsb.ca
Please remember to include an appropriate and specific subject for the e-mail.
2.
A “DROP BOX” on D2L. The drop box for this assignment can be found using the following pathway: Assessments --- Drop Box --- Effects of External Stimuli Lab Report
(Under Unit 4).