Human Body Organ System

Organ Systems for Class 2 Science

In this concept, the students will understand what is an organ system. Here, the students will be introduced to different organs of the body, like the organs of Respiratory system, organs of excretory system, organs of the digestive system, and many more.

After reading the concept, students will be able to:

• Identify the correct level of organisation in the human body.
• Recall the functions of different organs of the organ systems.

Each concept is explained to class 2 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Organ Systems provided in PDF format.

The human body comprises several organ systems that control bodily functions, like digestion of food, responding to mosquito bites and many more. An organ system is built up of several organs.

Human Body Organisation Levels:

• Different organs work under the control of the brain and form organ systems.
• A few functions of human organ systems are mentioned below—
1. Maintaining proper body posture.
2. Moving different parts of the body.
3. Sensing everything around.
   
4. Breathing.
5. Eating and digesting the food.
6. Supplying essential nutrients and oxygen throughout the body.
7. Eliminating harmful liquid and solid wastes from the body.

1) Skeletal System Parts and Functions:

• This organ system is made up of bones, joints, and cartilages. All these remain covered by the skin.
• When we touch our hand, leg, or head, we can feel the hardness underneath the skin. These are the bones.
• They allow the body to remain in the correct posture and help in body movement.
• The joints are the parts that enable the body parts to bend and turn.

•  Bending arms to pick things up, kicking the football, etc.
• Cartilages are more flexible and softer than bones.

2) Muscular System:

• Bones need help from the muscles to move various body parts.
• The muscles are connected to the bones, and they work together.

•  Lifting heavy objects, talking, pushing or pulling the door, and many more.
• As per the work, there are different kinds of muscles in the body, such as muscles in the limbs, muscles in the eyelids, etc.

3) Nervous System:

• This system tells us about the changes in the environment and helps us to coordinate with the changes.
• The nervous system is controlled by the brain and the spinal cord, which tell other organ systems how to function.
  
  Examples:   During winter we feel cold and wear sweaters. We feel pain if we bump onto a wall or fall on the ground.
• A sensory system consists of the brain, spinal cord, and nerves.
• The bony skull protects the brain.

• The skin helps feel all kinds of senses in the environment.

4) Respiratory System:

• The organs of the respiratory system are the nose, air pipe, and lungs.
• This system helps to breathe fresh air and breathe out the used air through the nose.
• The air taken inside fills the lungs that transfer it to other systems.
• The same lungs receive used air and pass it to the nose through the air pipe.

5) Digestive System:

• The digestive organ system starts from the mouth and ends at the rectum.
• Organs of this system are the mouth (tongue and teeth), food pipe, stomach, intestine, and rectum.
• The food we eat gets broken down into small pieces by the teeth.
• Tongue help to mix it with saliva.
• After swallowing the food, it gets thoroughly mixed with the digestive juices in the stomach.
• The body absorbs the useful nutrients of the food.
• The unwanted things are removed as solid waste from the rectum.

6)Components of Circulatory System:

• This system transports blood from the heart to the different organs of the body.
• Along with blood, it also transports the nutrients released from the food.
• The circulatory system helps to transport oxygen to all the parts of the body through blood.
• This system includes the heart and the network of arteries and veins.

7) Urinary System:

• Like the solid wastes released from the body, we must also remove harmful liquid wastes.
• To get this done, we have a filtration system inside our bodies.
• It includes the kidney, urinary bladder, and urethra.
• The kidney filters fluids, the urinary bladder stores the waste as urine for some time, and the urethra releases it outside the body.
• This system helps to balance the water content of our bodies by removing other waste materials.

New Words:

Spinal Chord: A long tube of nerves that run from the base of the brain.

Skull: A bony hollow covering that protects the brain.

Breathing: When we take in the fresh air by the nose and release the used air coming from the lungs, it is called breating.

Nutrients: Components of food that help in our growth and development

Did you know?

• We do not control the muscles of the heart and other internal organs. But they work continuously.
• Lungs are paired respiratory organs that provide oxygen to the circulatory system via blood.