The Skeletal System Part 1: The Skeleton

The skeletal system has 5 main functions.

4. Produces blood cells

3. Protects vital organs

5. Stores minerals

1. To give shape and support

2. Allows you to move

Five Functions

The skeletal system is made of 3 parts:

Strong living tissue – 206 in total

Bones

Tissue more flexible than bone

Tissue that holds bones in place

Cartilage

Ligaments

Three Parts

Bones are complex living structures.

Bone is one of the strongest tissues in the human body – and one of the lightest!

Bones are made of 4 materials:

Compact Bone

Cartilage

Spongy Bone

Bone Marrow

Bones

Compact Bone

Solid outer layer of bone

Hard and dense, but not totally solid

Contains blood vessels

Constantly changing

Compact Bone

Spongy Bone

Found at ends of bones

Honeycomb shaped – lots of small spaces within it

Light but very strong

Houses the bone marrow

Spongy Bone

Cartilage

Covers the ends of bones

Smooth, slippery & flexible

Acts as a shock absorber

Reduces friction from bones rubbing against each other

Cartilage

Bone Marrow

Soft connective tissue

Two types of marrow: red and yellow

Red makes red blood cells

Yellow stores fat for energy

Bone Marrow

Compact Bone

Marrow

Cartilage

Spongy Bone

Bone Anatomy

In your arms, legs

Long Bones

Types of Bone

Wrist or ankle bones

Short Bones

Types of Bone

Skull, shoulder blades

Flat Bones

Types of Bone

In your spine & ears

Irregular Bones

Types of Bone

The Skeleton

The Skeleton

Any Questions?

The Skeletal System Part 2: Joints

e.g. hip, shoulder

A joint is where two bones meet.

Joints allow bones to move in different ways.

There are 2 major types of joints:

e.g. skull

Allow a range of movement

Movable Joints

Allow little or no movement

Immovable Joints

What is a Joint?

Where two or more bones fuse together

e.g. skull

Immovable Joint

Immovable Joint

There are 4 types of movable joints.

Pivot Hinge

Ball & Socket Gliding

Movable Joints

Where one bone rotates around another

e.g. neck, lower arm

Pivot Joint

Pivot Joint

Moves forward and backward

e.g. knee, elbow

Hinge

Hinge Joint

Can freely move one bone in a circle:

widest range of motion

e.g. shoulder, hip

Ball & Socket

Ball and Socket Joint

One bone can slide over another

e.g. wrist, ankle

Gliding

Gliding Joint

Bones must be held together at joints.

Ligaments are strong bands of rope-like tissue that hold bones in place.

Ligaments connect bone to bone.

They keep bones from slipping out of joints.

Ligaments

Bones can rub against each other at joints.

Cartilage is a smooth, flexible tissue that reduces friction between bones

Cartilage covers the ends of bones at joints

It acts as a cushion and keeps joints smooth

Cartilage

Muscles move bones at joints.

Tendons are rope-like bands of tissue that pull on bones at joints.

Tendons connect muscle to bone.

Tendons allow you to move your body

Tendons

Tendon

Cartilage

Ligament

Tendons

Any Questions?