An introduction to Bones for Grade 8 health

1. The Skeletal System

2. What is the Skeletal system?
Your Skeletal system is all of the bones in the body and the tissues such as
tendons, ligaments and cartilage that connect them.
Your teeth are also considered part of your skeletal system but they are not counted as
bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance
in your body.
How does the Skeletal System help us?
The main job of the skeleton is to provide support for our body
Your skeleton also helps protect your internal organs and fragile body tissues
Bones provide the structure for muscles to attach so that our bodies are able to move.
Our bones have red bone marrow that make blood

3. How does the Skeletal System help us?
The main job of the skeleton is to provide
support for our body
Your skeleton also helps protect your
internal organs and fragile body tissues
Bones provide the structure for muscles to
attach so that our bodies are able to move.
Our bones have red bone marrow that
make blood cells
Bone Question - Who has more bones a baby or an adult?

4. Bones have their own nerves and blood vessels, and they do
various jobs, such as storing body minerals like calcium. Bones are
made of a mix of hard stuff that gives them strength and tons of
living cells which help them grow and repair themselves.
Periosteum - blood cells enter the bone to keep it
healthy, forms new bone
Compact bone - gives bone its strength
Yellow bone marrow - mostly fat cells
Spongy bone - filled with open spaces that has
red bone marrow that makes red blood cells
Answer - Babies have more than adults! At birth, you have about 300
bones. As you grow older, small bones join together to make big ones.
Adults end up with about 206 bones

5. Young bones - babies bones contain cartilage that
gets slowly replaced with hard bone as the child
ages.
Children - bones grow, the periosteum adds new
bone to the outside cells on the inside of the bone
destroy cells.
Middle Age - bone loss increases faster that
growth
Exercise puts a strain on bones and helps
them to become stronger. vitamins A, C, and
D are also important for bones.

6. Common Scientific
Name Name
skull cranium
jawbone mandible
collarbone clavicle
shoulder scapula
blade
breast bone sternum
funny bone humerus
spine vertebrae
hips pelvis
wrist carpals
thigh bone femur
kneecap patella
shin bone tibia
ankle tarsals

7. Bone Joints
Your skeleton has over 200 joints. Joints are where bones come together.
Ligaments are strong inelastic bands of connective tissue that help hold bones
together at joints
Where the bones come together at joints there is a cushion of cartilage that helps protect
the bones. Cartilage helps to prevent the bones from rubbing against each other and
wearing down the bone

9. Types of Joints
Pivot - Pivot joints allow for rotation such as the neck
Ball And Socket - in which the spherical head of one bone lodges in the spherical cavity of
another. In the shoulder joint, the humerus (upper arm bone) fits into the socket of the
shoulder blade
Hinge - found in the elbows and the joints of the fingers and toes. Hinge joints allow
movement in only one direction. The hinge joint of the knee, the body's largest joint
Saddle - allows movement in two directions. The saddle joint gives the human thumb the
ability to "cross over" the palm of the hand.
Gliding - Lets bones slide over one another like in the wrist and ankle

10. Tendons
Connect Muscle to Bone