CK-12 Foundation
Ck 12: Life Science: Organization of the Human Body
[Free Registration/Login may be required to access all resource tools.] Cells, like these nerve cells, do not work in isolation. To send orders from your brain to your legs, for example, signals pass through many nerve cells. These cells...
CK-12 Foundation
Ck 12: Life Science: Human Skeletal System
[Free Registration/Login may be required to access all resource tools.] How important is your skeleton? Can you imagine your body without it? You would be a wobbly pile of muscle and internal organs, and you would not be able to move....
TED Talks
Ted: Ted Ed: Could We Survive Prolonged Space Travel?
Prolonged space travel plays a severe toll on the human body: microgravity impairs muscle and bone growth, and high doses of radiation cause irreversible mutations. As we seriously consider the human species becoming space-faring, a big...