Blood Flow Experiment

Blood flow is affected by pressure and resistance by the formula: F = P/R

Since flow and pressure are directly related, an increas in pressure will result in an increase is flow and vice versa.
Blood flow and resistance are inversely related, so an increase in resistance will decrease the flow and vice versa.

Resistance factors that affect blood flow are

• Length of the vessel
• Diameter of the vessel
• Viscosity of the blood flowing through the vessel

In this experiment both pressure and resistance will be observed as to how they will affect flow

Materials:

2 sets of 3 different size tubes (straws could work) : 1/8 ", 1/4", 1/2" diameter
2 sets of 3 different fluids (water, catsup, corn syrup)
Stop watch

Measure one set of tubes and cut tubing into 1/3 vs 2/3 (not in half) so you will have 3 different lengths for each diameter.
The original tubing length and the two partial tubing lengths.

Pressure, Resistance, and Viscosity

obtain 6 tubes (3 different diameters, 3 differernt lengths)
obtain 1 set of the 3 different liquids
Have someone use the stop watch and time how fast each of the fluids move through the various lengths and diameters of the tubing when the tubing is held at a 20 degree angle from the table, 45 degree angle from the table and 90 degrees from the table.

Record your findings and analyze how flow was affected

Sample Data Sheet:

Water through 1/8" diameter of ______ (original) length at 20 degree angle = _________ seconds
Water through 1/8" diameter of ______ (original) length at 45 degree angle = _________ seconds
Water through 1/8" diameter of ______ (original) length at 90 degree angle = _________ seconds

Repeat this for water through 1/4" diameter at the 1/2" diameter tube at the various angles and record findings.

Set up again for corn syrup and again for catsup and create a data sheet to record findings at the various diameters and angles using the original length of tubing.

How does pressure (angle) and viscosity affect blood flow?

Repeat experiment using the other lengths of tubing and compare to original data
How did the length of the tube affect the flow at the different diameters and pressures (angles) ?

How does the body control the threeresistance factors to maintain normal blood flow?
What conditions could create a change in blood vessel length (longer or shorter)?