Plaque (biology) facts for kids

A plaque in biology is a flat area of growth. It's like a patch or a thin layer that can form in different places. You might have heard of dental plaque, but the word "plaque" is also used for other things in the world of living organisms.

What is Plaque?

A plaque is often a flat, thin layer of something that grows or builds up. It can be made of living things, like bacteria, or non-living things, like certain proteins or fats. The word "plaque" comes from a Greek word meaning "flat plate."

Plaques Made by Bacteria

Bacteria are tiny living things, so small you need a microscope to see them. They can form plaques in a few ways.

Bacterial Growth in Labs

Sometimes, scientists grow bacteria in a lab on a special dish called an agar plate. This plate has a jelly-like food that bacteria love. When a single bacterium starts to grow, it multiplies and forms a visible, flat spot. This spot, made of millions of bacteria, is called a plaque. It helps scientists study how bacteria grow.

Dental Plaque

One of the most common types of plaque is dental plaque. This is a sticky, colorless film of bacteria that constantly forms on your teeth.

• It feels fuzzy if you run your tongue over your teeth before brushing.
• These bacteria feed on sugars from the food you eat.
• As they eat, they produce acids that can damage your tooth enamel, leading to cavities.
• If not brushed away, dental plaque can harden into something called tartar, which can only be removed by a dentist.
• Brushing and flossing regularly helps remove dental plaque and keep your teeth healthy.

Plaques Inside the Body

Plaques can also form inside the human body, and sometimes they can cause health problems.

Brain Plaques

In some brain conditions, like Alzheimer's disease, tiny clumps of a protein called amyloid beta can build up outside brain cells. These clumps are called plaques.

• They are sometimes called "senile plaques" because they are often found in older people.
• These plaques can interfere with how brain cells communicate, which can affect memory and thinking.
• Scientists are still studying exactly how these plaques cause problems in the brain.

Artery Plaques

Another type of plaque can form inside your arteries. Arteries are like tubes that carry blood from your heart to the rest of your body.

• These plaques are made of fatty substances, cholesterol, calcium, and other things from your blood.
• When these fatty plaques build up, the condition is called atherosclerosis.
• The plaques can make the arteries narrower and harder, making it harder for blood to flow through.
• This can lead to serious health issues, like heart attacks or strokes, because parts of the body might not get enough blood.
• Eating healthy foods and exercising can help keep your arteries clear.