Part A (blood pressure data)
Aim: To determine statistically whether moving from a supine to a standing position significantly influences heart rate and mean arterial blood pressure (MABP).
Cardiovascular data, obtained during Practical 3: Cardiovascular Physiology, is provided separately as an Excel spreadsheet entitled ‘STATS blood pressure & heart rate data AUG 2020’. It will show six columns of data: supine diastolic blood pressure, supine systolic blood pressure, standing diastolic blood pressure, standing systolic blood pressure and heart rate for supine and standing.
All six measurements are taken from the same set of subjects.
Whether the subject was male or female will be indicated in a seventh column: male (M) and female (F).
Note that you may need to sort the data into separate columns for male and female.
Note the units of measurement for blood pressure (mmHg) and heart rate (beats per min).
Answer all parts of the question
Put your answers in the boxes provided. Do not move or re-size the text boxes.
1). Provide the formula for calculating mean arterial blood pressure (MABP) from measurements of diastolic and systolic blood pressure.
| MABP = Cardiac Output X Total Peripheral Resistance |
[1 mark]
2). Using Excel, calculate four new columns, giving for each subject their MABP supine, MABP standing, the standing – supine difference in MABP and the standing – supine difference in heart rate.
From the new columns, again using Excel, calculate for the whole class, and for males and females separately, the mean and standard error of the mean (SEM) for both MABP and heart rate. Do this separately for the supine position, the standing position and for the standing – supine difference.
This should result in a total of eighteen sets of mean ± SEM values.
Create two tables that summarize the effects of moving from a supine to a standing position, one for MABP and one for heart rate. They should include mean and SEM for supine, standing and the standing – supine difference, for males separately, females separately and for the whole class (males & females combined). They should also contain the numbers of subjects and units of measurement, a title and a legend which states briefly how the experimental data were obtained (i.e. summarizes what was done in the practical).
Round the values up to an appropriate number of decimal places. Note that the number of decimal places that is appropriate for presentation purposes is not necessarily the same as the number of decimal places that is appropriate for use in calculations. Insert the tables in the box provided on the next page.
