Bones make up the skeletal system.  They are living, and they protect the body’s internal organs, support the body, make blood cells, store minerals, and provide a place for muscles to attach.  Inside bones is a substance called marrow.  It’s a thick fluid that makes blood cells that help the body fight off infection, and [...]

The heart and blood vessels (veins and arteries) make up the circulatory system.  The heart pumps blood that carries oxygen and nutrients to all parts of the body.  The heart is the size of a fist and acts like a pump to circulate blood.  Tell your carschoolers to put their hands over the center of [...]

Skin is an organ.  In fact, it is the largest organ of the human body.  Skin forms a protective layer over the body to help prevent injury and disease, keeps moisture in the body, regulates the body temperature, produces vitamin D, and excretes waste.

Looking at skin through a magnifying glass or jeweler’s loop is a [...]