Types of skeletons, parts and their functions

In a nutshell

Humans and many other animals have a skeleton made of bones, which grow as the animal grows. The skeleton acts as a frame that supports and protects the animal, as well as help it move. Skeletons can be found on the inside or outside of an animal's body, depending on the type of animal.

Types of skeleton

Endoskeleton

Some animals have a skeleton made of bones on the inside of their bodies. When a skeleton is on the inside of an animal, it is called an endoskeleton.

Examples

Humans and other mammals have an endoskeleton.

Exoskeleton

Some animals have a skeleton on the outside of their body that is not made of bones.

Examples

Crabs and lobsters have exoskeletons.

Note: There are some animals that lack an internal or external skeleton completely, examples of these include jellyfish and slugs.

Skeleton parts

Below are the main parts of a human skeleton that you should know. Some of these bones have a scientific name in brackets.

1. Skull (cranium), 2. Collarbone (clavicle), 3. Ribs, 4. Backbone (vertebrae), 5. Pelvis, 6. Thigh bone (femur), 7. Kneecap (patella)

Function of the skeleton

The three main functions of the skeleton are movement, protection and support.

Support

Inside the body, the skeleton has muscles, blood vessels and skin wrapped around it. The bones in the neck, legs and back keep the body upright and stop it from collapsing. There are three important parts of the skeleton that support the body.

Part of the skeleton	Function
Collarbone (clavicle)	Supports the shoulders.
Pelvis	Supports the upper body.
Thigh bone (femur)	Supports the weight of the body.

Movement

A skeleton is made up of lots of bones joined together. The place where two bones meet is called a joint and bones that form a joint are attached to each other by ligaments. Ligaments, joints and muscles all help the skeleton to bend and generate movements.

Example

Ligaments, joints and muscles help when climbing stairs.

Protection

Another function of the skeleton is to protect the delicate parts of the body, like organs.

Part of the skeleton	Function
Skull (cranium)	Protects the brain.
Ribs	Protects the heart and lungs.
Backbone (vertebrae)	Protects the spinal cord.
Kneecap (patella)	Protects the knee joint.