2. Standard 4.4.10 Explain that if germs are able to get inside the body, they may keep it from working properly. Understand that for defense against germs, the human body has tears, saliva, skin, some blood cells, and stomach secretions. Also note that a healthy body can fight most germs that invade it. Recognize, however, that there are some germs that interfere with the body's defenses. Activity: http://www.indianastandardsresources.org/files/sci/sci_4_4_10.pdf
14. Activity: Germs Keep Out How do germs get into our bodies? Germs can enter the body through many places like your mouth, nose, eyes, or broken skin. Look at this apple. Is it possible that when this apple was growing on its tree, that it could have become infected by germs? How could the apple get an infection? Can one volunteer please come up and take a bite of this apple?
15. Activity: Germs Keep Out! Do you think germs would have had an easier time infecting the apple if its skin was broken? The skin of an apple protects the apple much like the skin of a human protects the human from germs and disease. Once the skin is broken, it is easier for germs to get inside and hurt the body (and the apple). What happens when germs get inside the body? What happens when your body gets an infection? Once germs invade the body, they stay for a while and draw energy from the body. They take nutrients and energy and produce wastes.
16. Activity: Germs Keep Out! You come in contact with germs everyday. If you come in contact with so many germs why are you not sick all of the time? The body has special defenses to fight off germs and today we will learn a few of them. Can I have a volunteer write the following words on the chalkboard: tears, saliva, skin, white blood cells, stomach secretions. How do you think these things help fight off germs? Tears wash germs and particles out of the eye; saliva in a person’s mouth is made of substances that kill germs; unbroken skin serves as a protective barrier so that germs cannot enter; some white blood cells find and attack invading germs; stomach secretions are liquids in the stomach that contain chemicals that kill germs.