Cells, tissues and organs
A cell is the smallest living part of any organism.
It is like a tiny building block that makes up all plants, animals, and humans.
Tissues are groups of similar cells that work together to do a specific job.
Example: In your body, many muscle cells join together to form muscle tissue that helps you move.
Organs are body parts made of different tissues working together to do a special job.
Example:
Heart – pumps blood
Lungs – help you breathe
Stomach – helps digest food
Brain – controls your body
Skin – protects your body
Nerve cells (also called neurons) are special cells in your body that carry messages between the brain, spinal cord, and all other parts of the body.
Blood vessels are tubes in your body that carry blood everywhere.
They are like tiny roads that help blood travel to all parts of your body.
There are three main types:
1. Arteries – carry blood away from the heart
2. Veins – carry blood back to the heart
3. Capillaries – very tiny vessels where oxygen and food pass into the cells