Mouth

From Encyclopedia Jr, free information reference for Kids

Sagittal section of nose mouth, pharynx, and larynx.

A human mouth.

For the mouth of a river, see delta and estuary.

The mouth, also known as the buccal cavity or the oral cavity, is the opening through which an animal takes in food and water. The mouth of a planarium is in the middle of its belly.

[edit] Mouths of animals

Most animals have a complete digestive system, with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify animals into protostome and deuterostome.

Some animals, such as the cnidarians, the brachiopods, and the planaria, do not have a separate anus, and thus expel waste through the mouth.

In many animals, the mouth has mouthparts to chew food, hold food, or inject poison. In arthropods, they are external modified legs; in gnathostome vertebrates they are internal.

[edit] The human mouth

The human mouth is covered by an upper and lower lip. They play an important role in speech (it is part of the vocal apparatus), facial expression, kissing, drinking (especially with a straw), and smoking. Infants are born with a sucking reflex, by which they instinctively know to suck for nourishment using their lips and jaw. Lips are often adorned with lipstick or lip gloss although in most human cultures this is an affectation for females only. The philtrum is the vertical groove in the upper lip, formed where the nasomedial and maxillary processes meet during embryo development. When these processes fail to fuse fully, a hare lip and/or cleft palate can result. The nasolabial folds are the deep creases of tissue that extend from the nose to the sides of the mouth. One of the first signs of age on the human face is the increase in prominence of the nasolabial folds.

According to western etiquette, the mouth is kept closed, especially when chewing.

The mouth starts digestion by physically chewing the food and breaking it down with saliva.

[edit] See also

• Head and neck anatomy

[edit] People and characters famous for their mouth

• Animal
• Beaker
• Ismail Yasin, famous for his large mouth.
• Jim Carrey, famous for his "grinning idiot" roles
• John Cleese, famous for his stiff upper lip performances
• The Coneheads (in a famous scene in the movie, the father opens his mouth really wide while visiting the dentist.)
• Cookie Monster
• Macauley Culkin in Home Alone
• Farrah Fawcett
• Mick Jagger
• Scarlett Johansson (famously big lips)
• Angelina Jolie (same reason as Scarlett Johansson)
• Buster Keaton (in most of his films he kept his mouth closed and expressionless)
• Richard Kind
• The MGM Lion
• Mona Lisa (the internationally most famous smile)
• Jack Nicholson (famous for his grinning smile)
• Pepe the Prawn
• The Rolling Stones logo (lips with a long tongue)
• The Scream, painting by Edvard Munch
• Carly Simon
• Gene Simmons (famous for his long tongue)
• Guy Smiley
• Steven Tyler

Human anatomical features

HEAD: Skull - Forehead – Eye – Ear – Nose – Mouth – Tongue – Teeth – Jaw – Face – Cheek – Chin NECK: Throat – Adam's apple - Larynx TORSO: Shoulders – Spine – Chest – Breast – Ribcage – Abdomen – Belly button Sex organs (Penis/Scrotum/Testicle/Clitoris/Vagina/Ovary/Uterus) – Hip – Anus – Buttocks LIMBS: Arm – Elbow – Forearm – Wrist – Hand – Finger (Thumb - Index finger - Middle finger - Ring finger - Little finger) – Leg – Lap – Thigh – Knee – Calf – Heel – Ankle – Foot – Toe (Hallux) SKIN: Hair