Human organs system
1) Nervous System
Definition: Controls the body.
Main: Sends messages.
Examples: Brain, nerves.
Interesting: Works very fast.
Fun Fact: Brain has billions of cells.
2) Circulatory System
Definition: Moves blood.
Main: Carries oxygen.
Examples: Heart, blood vessels.
Interesting: Heart beats all day.
Fun Fact: Heart never rests.
3) Respiratory System
Definition: Helps us breathe.
Main: Takes in oxygen.
Examples: Lungs, nose.
Interesting: Breathing is automatic.
Fun Fact: You breathe thousands of times daily.
4) Digestive System
Definition: Breaks down food.
Main: Gives energy.
Examples: Stomach, intestines.
Interesting: Starts in mouth.
Fun Fact: Small intestine is very long.
5) Skeletal System
Definition: Gives shape.
Main: Supports body.
Examples: Bones, skull.
Interesting: Adults have 206 bones.
Fun Fact: Babies have more bones.
6) Muscular System
Definition: Helps movement.
Main: Moves bones.
Examples: Arm muscles.
Interesting: 600+ muscles.
Fun Fact: Heart is a muscle.
7) Excretory System
Definition: Removes waste.
Main: Cleans blood.
Examples: Kidneys.
Interesting: Works daily.
Fun Fact: Kidneys filter a lot of blood.
8) Reproductive System
Definition: Helps make new life.
Main: Active at puberty.
Examples: Ovaries, testes.
Interesting: Different in boys and girls.
Fun Fact: Only used to create babies.
9) Endocrine System
Definition: Controls hormones.
Main: Controls growth.
Examples: Thyroid gland.
Interesting: Works slowly but strongly.
Fun Fact: Pituitary is master gland.
10) Immune System
Definition: Fights germs.
Main: Protects body.
Examples: White blood cells.
Interesting: Remembers infections.
Fun Fact: Vaccines train it.
11) Integumentary System
Definition: Outer protection.
Main: Covers body.
Examples: Skin, hair.
Interesting: Skin is largest organ.
Fun Fact: Skin renews itself.