BACKGROUND:
A pulse is created when the ventricles of the heart
contract and force blood into the arteries. Each beat of the heart
makes an artery stretch thereby causing a pulse within the artery.
Blood in the arteries has a much higher pressure than the blood in the
veins. Therefore, blood found in the arteries moves much faster than
blood found in the veins. That is why it is so difficult to
stop an artery from bleeding and why so much blood is lost if an artery
is cut.
Blood pressure is a measure of the pressure of the blood
on the walls of the arteries. The students should observe the mechanical
heart found in the module so they can see a "pulse" in motion.
PROCEDURE:
- This lab has the students detecting their own
pulse rates and calculating the number of beats per minute. They
will determine their pulse rates while standing still and after running. Use
the model of the heart to go over the different components of the heart
(see Pre Lab).
- The purpose of this lab is to determine if boys and girls have
a different pulse rates. The students will have to determine the
average of the class for both girls and boys and then compare this with
the average pulse rate. This lab may take a considerable longer time
than most of the other labs, because you will have to tabulate each child's
pulse rate.
- Reinforce the information given in the pre lab.
