Have the students research some of the theories concerning high blood pressure and ask them to report on lifestyle adjustments that could minimize risk. Invite a health care professional to come in to class and take students blood pressure, and graph the class range. Have students squeeze an unrestricted tube to see how much pressure it takes to force the water out, then clamp the tubing part way closed to represent a constricted artery. They will see that it takes much more pressure to force the water through. In fact, if the pressure gets to high, the tube may blow off the bottle representing a hemorrhage.
Bruises usually happen when muscle tissue gets a sudden blow with a blunt object.
When this happens, the skin doesn't break, but capillaries under the skin rupture and slowly leak blood which pools up. Usually, the capillaries seal themselves rather quickly and then the healing process begins. During this phase, the bruise usually changes from purple, to brown or even yellow. Generally, if cold is applied to a bruise right after it happens, the amount of internal bleeding will be reduced and the bruise will heal faster. If you strike the bag sharply with a blunt object, several of the eggs will break and their contents will leak into the bag.