* Tissues: Groups of similar cells that work together to perform a specific task. There are four main types of tissues:
* Epithelial tissue: Covers surfaces, lines cavities, and forms glands.
* Connective tissue: Supports and binds other tissues (like bone, blood, cartilage).
* Muscle tissue: Responsible for movement.
* Nervous tissue: Transmits and receives information.
* Organ Structure: These tissues are arranged in a specific way within an organ, allowing them to work together efficiently. For example, the stomach has layers of epithelial tissue for digestion, muscle tissue for churning food, and connective tissue for support.
Here's an analogy: Imagine building a house. The bricks, windows, and plumbing are like individual tissues. When you put them together according to a plan, you create a functional house, which is like an organ.
Some examples of organs and their functions:
* Heart: Pumps blood throughout the body.
* Lungs: Exchange oxygen and carbon dioxide.
* Brain: Controls thoughts, emotions, and actions.
* Stomach: Digests food.
* Liver: Filters blood and produces bile.
* Kidneys: Filter waste from the blood.
Key takeaway: An organ is a complex structure made up of various tissues working together to perform a specific function.
