Human mouth

Your mouth is a very important part of your body. It is the first stop in the alimentary canal. This is the long path that food takes through your body. The mouth receives food and makes saliva to help. The inside is lined with a wet layer called the oral mucosa.

This lining keeps the inside of your mouth moist. The mouth also helps you talk to other people. While your throat makes the main sounds, your mouth helps too. Your tongue, lips, and jaw work together to make speech.

The mouth has two main areas inside it. The first area is called the vestibule. This is the small space between your teeth, lips, and cheeks. The second area is the oral cavity proper. The sides and front are held by the alveolar process. This is the part of the bone that holds your teeth.

The roof of this space is the hard palate. The floor is made of the mylohyoid muscles. Most of your tongue sits on this floor. The oral mucosa lines the tongue and the jaw. This lining gets wet from salivary glands.

Many parts of the mouth work together to feel things. Nerves carry messages from your teeth and gums to your brain. These nerves come from the trigeminal nerve. The maxillary nerves help you feel your upper teeth. They include the superior alveolar nerves. These nerves form a dental plexus above your teeth.

The mandibular nerves help you feel your lower teeth. The inferior alveolar nerve runs inside your lower jaw bone. This nerve gives off branches to all your lower teeth. These branches form the inferior dental plexus. Many different nerves help you feel your gums and cheeks.

Your mouth also helps you breathe and eat. Most people breathe through their nose. Mouth breathing happens if the nose is blocked. It works as a backup system for your body.

Babies are born with a sucking reflex. They know how to use their lips and jaw to eat. The mouth also helps with chewing and biting food. Some people use their mouths in special ways. Artists who cannot use their hands may use their mouths. They can hold a brush with their teeth. They use their tongue and cheek muscles to paint. This can be hard work for their neck and jaw.

Your lips are very useful for showing feelings. They form a line that can change shape. A smile looks like an up-open parabola. A frown looks like a down-open parabola.

The lips also mark where the inside of your mouth meets your skin. There is a small dip above your lip called the philtrum. This is formed during embryo development. It happens where the maxillary and nasomedial processes meet. If these parts do not fuse, a person might have a cleft lip. You might also see lines from your nose to your mouth. These are called nasolabial folds. They often become more visible as people age.