Skeleton and Muscle System

We are movable. We are not static at one place. We move from one place to another. We can also move our hands, legs, head and so on. All these movements are possible by the mixture of two systems in human body - bones and muscles. All bones together make skeleton system and all muscles together make muscle system.

Skeleton System

Skeleton is a structure of bones which is hard and gives movement to many parts of body. These give support to the body. The main parts of skeleton are: 

  • Skull - box giving protection to human mind which starts from brain and ends at spinal cord
  • Ribs - these cover lungs and heart
  • Bones of shoulder and hips

The total number of bones in our body is 206. The longest bone is femer in thighs and the smallest bone is behind the ear drum smaller than a grain of rice.


Joints are those places where one bone gets connected to other bones. For example, knee and below joints are moveable and static. Moving joints is a structure that keeps two bones together is called tendon.

There are muscles attaches to bones which move automatically.

There are three more functions of skeleton system:

  1. It gives shape and support to body.
  2. It gives security of soft parts of body like skull to brain and rib makes lungs and heart secure.
  3. Bones give place to muscles join and helps in the movement.

Muscle System

There are more than 600 muscles in human body. All these muscles provide movement to bones as well as soft body parts like heart, intestines. 

Types of Muscles

There are two types of muscles: 

1. Voluntary muscles - these muscles work according to our wish. Example - muscles related to the movements of hands and legs. These muscles are connected to bones. 

2. Non voluntary muscles - These muscles are not in our control and keep working automatically. Intestine muscles or stomach muscles work automatically and keeps on forwarding the food from time to time.

Muscles are also found in the walls is of arteries and veins. Heart muscles are also different in their structures. Their structures are related to voluntary muscles but their work is non voluntary. This is also called heart muscles. All muscles are made up of fiber.

How does a muscle work?

Muscles contract to do work. Voluntary muscles on one end are static or fixed and together are connected to moving bones. When a muscle contracts the movement of the bone happens as bone is pulled towards contracted muscles.

Contracted muscles get smaller and pulls its motion head giving way to movement. The moving end if muscle gets connected to bone by a skull. When contraction ends pulling of bones also ends and muscles come back to old form and moves in opposite direction.

Function of Muscle System

  1. Muscles help in the movement of our body organs like walking, running or holding objects.
  2. They help us in swallowing and chewing food.
  3. They help in expansion and contraction of chest leading to our breathing system.
  4. They make heart pace muscles.