How Do Cells Work Together?

Groups of similar cells join forces to form tissues. There are four main types:

• Epithelial tissue: Covers and protects surfaces.
• Connective tissue: Supports and binds other tissues.
• Muscle tissue: Moves parts of the body.
• Nervous tissue: Sends electrical signals.

Building Organs

Tissues combine to create organs, such as the heart, lungs, and stomach. Each organ has a special job. For example, your heart pumps blood, and your lungs help you breathe.

Organ Systems

Organs work together in systems, like:

• Digestive system: Breaks down food.
• Circulatory system: Moves blood around.
• Nervous system: Controls actions and senses.

Everyday Importance

When you eat, your digestive system (mouth, stomach, intestines) works as a team to turn food into energy. When you exercise, your heart and lungs work together to supply oxygen to your muscles.