Science: Muscles & Bones - ch.3.5 Flashcards
3 main functions of the skeleton
- Support
- Protection
- Movement
Axial skeleton
- 80 bones
- Protects organs
- skull, vertebral column, ribs
Appendicular skeleton
- 126 bones
- Allows movement
- arms and legs
Bones
- Structures that makes up the skeleton
- They are lightweight and living
Compact bone
- makes up the outer layer of the bone
- dense and heavy which gives the bone its strength
Spongy bone
- Light and honeycombed inner part of the bone
- Filled with bone marrow
Bone shaft
Long bones have a cavity that carries blood vessels
Bone marrow
A jelly-like material that produces blood cells
Joint
Where 2 bones are in contact
What is cartilage?
A smooth slippery material that covers the ends of bones
What is the function of cartilage?
It helps cushion the impact of movement
Synovial fluid
- Lubricates the bone ends
- Allows them to slide over each other freely
Hinge joint movement
Allows movement in only one plane (backwards and forwards)
Hinge joint example
Elbow joints, knee joints, fingers
Ball-and-socket joint bones
One bone has a ball shaped surface that fits into a cup-shaped socket in the other bone
Ball-and-socket joint movement
The bone with a ball can complete all types of movement
Ball-and-socket joint example
Hip and shoulder joints
Pivot joint bones
Moves by a ring- shaped bone turning around another bone shaped like a finger
Pivot joint movement
Allows a wide range of movement
Pivot joint example
Neck and head
Saddle joint movement
Allows movement in both directions
Saddle joint example
Base of thumb, ankle
Ligaments
flexible tissue that hold the bones in a joint together
Tendons
Elastic tissue that attaches muscles to bones
