1. The Skeletal System
Chapter 2, section 1

2. 4 Major functions of the Skeletal System
Provides shape and support to body
Enables you to move
Skeletal system works along with muscular system for this
Protects your internal organs
4. Production and Storage
Produces red blood cells
Stores fat and calcium until body needs them

3. What is the function of cartilage in adolescents and adults?
Protects bones and joints
Prevents surfaces of bones from rubbing against each other and reduces friction

5. Formation of Bones – Does bone development occur from the outside in or from the inside out? Answer: from the inside out
Before birth, most bone is actually cartilage
Gradually replaced by bone in infancy and childhood (cartilage does NOT just harden into bone…they are two DIFFERENT types of tissue)
How does this happen? Inside the bones are…

6. …Growth Plates new bone cells produced here
The cartilage that was first produced here, is now replaced, gradually, by bone tissue

7. What is the difference between cartilage and ligaments?
Cartilage – tissue that covers ends of bones. Function is to protect, cushion and reduce friction
Ligaments - tissue that connects bones to other bones at joints. Function is to stabilize the joints and keep them from shifting

9. Bones – The Inside Story
In this lab, you will be creating a model of a human long bone. Before you start, let’s review what you already know about the structure of bones from the reading.

10. Structure of Bones There are TWO main types of bone tissue:
Compact Bone
Spongy Bone

11. Compact Bone Makes up the hard, outer part of bone Dense web of fibers
Contains small canals that run through which carry blood vessels & nerves from surface to living cells in bone

12. Spongy Bone Just inside the compact bone
Located at the ENDS of the long bones
Makes most all of short bones (like wrist)
has many small spaces in it which makes bone strong but lightweight

13. Bone Marrow Found in the spaces of bones: 2 Types: 1) Red 2) Yellow-
produces blood cells
Found in spongy ends of long bones/some flat bones like ribs
2) Yellow-
stores fat that serves as an energy reserve
Found in longest part of long bones

14. Periosteum A membrane that surrounds bone
Covers all parts of bone that are not covered by cartilage
Blood vessels and nerves enter and leave through this membrane

16. Your Challenge Produce a model of a human long bone.
You may use any of the materials from the front of the room.
Model must represent the following parts of the bone:
Compact bone
Spongy bone
Bone marrow
Periosteum
Blood vessels
nerves

17. How Bones Form
Infants – Much of the skeleton is made up of cartilage (a connective tissue that is more flexible than bone)
As you grow, cartilage is gradually replaced by bone.
As an adult, cartilage covers the end of many bones where it acts as a cushion to keep bones from rubbing together at joints

18. Joints-a place in the body where two bones come together
Immovable - Allow little or no movement
Movable - Allow a wide range of movements
*Ball & Socket - Ex: shoulder, hip *Pivot – Ex: between top of neck & head *Gliding – Ex: ankle, wrist *Hinge – Ex: knee, elbow *Ligaments hold together bones *Cartilage covers the ends of bones *fluid lubricates ends of bones
Ex: skull, joint where ribs meet the sternum

19. Bone Health Balanced Diet – plenty of calcium & phosphorus
Exercise – makes bones stronger and denser
Prevention of osteoporosis – condition in which bones become weak and break easily
More common in women than in men
More common in older people
May be prevented by regular exercise throughout your life
May be prevented by diet rich in calcium and vitamin D throughout your life