SmallQuestions
What are teeth for? Teeth help you bite and chew food, shape speech sounds, and support the structure of your mouth and face. Different teeth have different jobs: incisors cut, canines tear, and premolars and molars crush and grind. Table of contents What are teeth for? Types of teeth and their functions How to care […]
Why should we brush our teeth? We brush to remove plaque and food, protect enamel and gums, and keep the mouth comfortable and healthy. Table of contents How often should you brush? Why brushing matters How to brush well Brushing tips for kids When to ask a dentist How often should you brush your teeth? […]
Why do we need sleep? Here is the evidence-based short answer. Why do we need sleep? Sleep gives the brain and body time to restore, organize information, regulate important systems, and prepare for the next day. It is an active biological process, not simply a period when nothing is happening. Table of contents What sleep […]
What makes us feel sleepy? Sleepiness comes from two interacting systems: a growing need for rest called sleep pressure and a body clock that times periods of wakefulness and sleep. Light, activity, illness, stress, caffeine, and the previous night’s rest can all change how sleepy someone feels. Table of contents Sleep pressure The circadian clock […]
Table of contents The heart’s main job How blood moves Heartbeat signals Common questions What does your heart do? Your heart is a muscular pump that moves blood through your body. Each beat sends blood to the lungs for oxygen and then to the brain, muscles, organs, and every other tissue. Blood also carries nutrients, […]
Table of contents Electrical signals One complete heartbeat What changes the rate Common questions Why does your heart beat? Your heart beats because electrical signals make its muscle contract and relax in a repeating rhythm. This moves blood to the lungs and then around the body. Electrical signals A group of specialized cells called the […]