1. LESSON EIGHT SKIN, BONES, MUSCLES
CHAPTER FIFTEEN
LESSON EIGHT
SKIN, BONES, MUSCLES

2. OBJECTIVES DESCRIBE WHY YOUR SKIN, BONES, AND MUSCLES ARE IMPORTANT.
DESCRIBE DISEASES OF THE SKIN, BONES, AND MUSCLES.

3. BELLRINGER IMAGINE WHAT A HUMAN BODY WOULD BE LIKE WITHOUT
SKIN, BONES, OR MUSCLES. WRITE A PARAGRAPH ABOUT
THE PROBLEMS A PERSON WOULD HAVE—BESIDES JUST
AN UNPLEASANT APPEARANCE—WITHOUT SKIN, BONES,
OR MUSCLES.

4. ESSENTIAL QUESTION
WHY ARE BONES CONSIDERED LIVING
TISSUE?

5. DEFINITIONS
SKIN YOUR SKIN IS A PROTECTIVE COVERING FOR YOUR BODY. IT RECEIVES SIGNALS FROM THE ENVIRONMENT, SUCH AS TOUCH OR PAIN.
BONES BONES ARE SOLID STRUCTURES MADE OF PROTEINS, MINERALS, AND CONNECTIVE TISSUE. YOUR BONES GIVE YOU STABILITY. THEY ALSO PROTECT IMPORTANT ORGANS, SUCH AS THE BRAIN AND THE SPINAL CORD.
MUSCLES YOUR MUSCLES ARE TISSUE THAT MAKE IT POSSIBLE FOR YOUR BODY TO MOVE.
BLOOD VESSELS INSIDE YOUR BONES DELIVER NUTRIENTS TO THE LIVING BONE CELLS. BONE MARROW, LOCATED IN THE CENTER OF THE BONE, IS WHERE BLOOD CELLS ARE FORMED.
SKIN SOME SKIN DISEASES, SUCH AS SKIN CANCERS, ARE CAUSED BY EXPOSURE TO SUNLIGHT. OTHER SKIN DISEASES, SUCH AS PSORIASIS, HAVE NO KNOWN CAUSE.
BONES OSTEOPOROSIS IS A BONE DISEASE THAT CAUSES LOSS OF BONE DENSITY, SO BONES BECOME BRITTLE. RICKETS RESULTS FROM A LACK OF VITAMIN D, AND CAN BE TREATED WITH A PROPER DIET.
MUSCLES MUSCULAR DYSTROPHY IS A GROUP OF SEVERAL INHERITED MUSCLE DISEASES THAT CAUSE MUSCLES GRADUALLY TO BECOME WEAK AND DISABLED.