movable joint Most mobile type of joint; the most common type of joint in the body.
osteoarthritis A condition in which the cartilage at the ends of the bones breaks down.
osteoporosis Disease in which bones become lighter and more porous than normal.
periosteum Tough, shiny, white membrane that covers all surfaces of bones.
pivot joint Joint structure in which the end on one bone rotates within a ring-type struc-
ture which can be made partly of bone and partly of ligament; example includes the
joint between the radius and ulna.
skeletal system Body system that is made up of bones, cartilage, and ligaments.
skeleton Sturdy scaffolding of bones and cartilage that is found inside vertebrates.
spongy bone Lighter and less dense than compact bone; found toward the center of the
bone.
sprain A ligament injury; usually caused by the sudden overstretching of a joint which
causes tearing.
Points to Consider
- How does your skeletal system interact with your muscular system?
- How might a broken bone affect the functioning of the muscular system?
- How do tendons differ from ligaments? How are they similar?
16.4 Lesson 16.4: The Muscular System
Lesson Objectives
- Identify the three muscle types in the body.
- Describe how skeletal muscles and bones work together to move the body.
- Describe how exercise affects the muscular system.
- Identify two types of injuries to the muscular system.