Human Body

Human Body Organ System for Class 4 Science

Here, the students will get an idea about the organisation of the human body. Our body is made up of different types of organs. This concept will introduce the students to human body organ system.

After reading the concept, students will be able to:

• Answer the following:
  • What is a cell?
  • What is tissue?
  • Types of organ systems in human body.
• Understand about organ systems like
  • Respiratory system functions.
  • Human circulatory system.
  • What is skeletal system?
  • What is nervous system?
  • Human digestive system.
  • Human excretory system.

Each concept is explained to class 4 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 of Human Organ Systems provided in PDF format.

• An organ is made with a group of tissues that perform specific functions in the body.
• The human body is built up of several organ systems that regulate all bodily functions.

Levels of Organisation in our Body:

Cell : A cell is the smallest unit of life. It is the structural and functional unit of the human body.

Tissue : A group of cells with similar structures and performing similar functions.

Organ : It consists of a group of tissues that carry out a particular function.

Organ System : A system consisting of a group of organs that work together to perform specific body functions.

Organism : A living thing capable of performing all life processes with the help of the organ systems.

There are six major organ systems present inside our body—

1. Circulatory System
2. Skeletal System
3. Nervous System
4. Respiratory System
5. Excretory System
6. Digestive System

Organ Systems	Parts of the organ system	Functions
Circulatory System	Heart Arteries Veins Blood capillaries	Helps in the circulation of blood. Carries oxygen and nutrients to the cells.
Skeletal System	Bones Joints	Helps in movement and locomotion. Helps in running, jogging and different kinds of physical activities.
Nervous System	Brain Spinal cord	Controls all kinds of body movements, body functions and thought processes.
Respiratory System	Nostrils Respiratory tubes Lungs	Helps in respiration. Helps to breathe in oxygen from the air and breathe out carbon dioxide.
Excretory System	Kidney Ureter Urinary bladder Urethra	Purifies blood by absorbing all toxic materials and excess water. Produces urine as an excretory product.
Digestive System	Esophagus Stomach Liver Pancreas Colon	Digests food. Absorbs nutrients from the food. Discharges undigested materials as faecal matter.

New Words

Did You Know?

Skin is the largest organ of the human body.

Our body has two kidneys, but surprisingly, we can survive with only one.

Other than bones, we also have muscles in the body that help in movement and locomotion.