Grade 3 Science (NSO) : Human body part 1

A look at the grade 2 lessons

Grade 2 Science (NSO): Human Body

Human beings: Parts of the body

Human beings : Sense organs

Our body is made up of different organs and organ systems. There are in all 12 systems in our body

Muscular System

Muscular system is the system of Human Body that provides motor power for all movements of body parts. Muscular system is composed of special tissue called muscular tissue. Muscles have the ability to contract actively to provide the force for movements of body parts.

Types of muscles:

  • Skeletal Muscles:

Striated, under voluntary control, found attached to skeleton, produce major movements of body parts

  • Smooth Muscles:

Non striated, not under voluntary control, found in soft organs of body, responsible for processes like digestion of food etc.

  • Cardiac Muscles:

Striated, involuntary, present exclusively in heart, responsible for pumping activit of heart, very strong and tough

Circulatory system

The circulatory system is a network consisting of blood, blood vessels, and the heart. This network supplies tissues in the body with oxygen and other nutrients, transports hormones, and removes unnecessary waste products. It is a system by which blood circulates in our body.

  • It consists of the heart, the blood and the bloood vessels (arteries and viens)
  • The heart is the main organ of this system
  • The heart pumps blood to different parts of the body. This blood is carried to different parts of the body through arteries and is brought back to heart, from the body, through veins.
  • Blood picks up oxygen from the lungs and food from the small intestine and supplies them to different parts of the body.

 

Immune system

The organs and processes of the body that provide resistance to infection and toxins. Organs include the thymus, bone marrow, and lymph nodes.

-portions of many different systems that fight disease