Digestion and Teeth
Concept: All About Tongue and Teeth
The tongue is a vital muscular organ present in the buccal cavity. The tongue has voluntary muscles.
It is attached to the base of the buccal cavity by a muscular fold called the frenulum.
Functions of the tongue:
The tongue performs some vital functions in the human body. These are—
- Mastication of food: The tongue helps in chewing food by making it soft by assisting in the mixing of food with saliva.
- Tasting of food: The tongue has tiny bumps on its surface called taste buds. These taste buds assist in distinguishing the different flavours of food like sweet, sour, bitter and salty.
- Speech: The tongue helps in speaking.
- Secretory function: It secretes mucus and some fluids which keep the oral cavity moist.
Structure of the tongue:
- The length of the human tongue varies from 3.1 inches to 3.3 inches in females and males, respectively.
- The outermost covering of the tongue is called the epithelium.
- This epithelium comprises taste buds and papillae.
- Taste buds are made of slender cone-shaped cells with a nucleus at the centre.
- There are around 2000 to 5000 taste buds on the tongue.
- These taste buds help detect different tastes like sweet, sour, bitter and salty.
Teeth are hard and bony structures found in the oral cavity. They grow from the jawbone and remain fixed to the gum.
Significance of teeth:
- Teeth are specialised for mastication and breaking of food.
- Mammals develop two sets of teeth during their lifetime.
- The first and second sets of teeth are called milk (or primary) teeth and permanent teeth, respectively.
Differences between milk teeth and permanent teeth:
|Milk Teeth||Permanent teeth|
Types of teeth:
There are four main types of teeth.
- There are 8 incisors. Each jaw comprises 4 incisors.
- They are located in the front of each jaw.
- Incisors are specialised in cutting and biting food.
- There are 4 canines; 2 located in each of the upper and lower jaws, respectively.
- They are located at the corner of the mouth.
- They have sharp triangular edges.
- They are specialised in tearing food like flesh.
- They are located between the canines and molars.
- They are 8 in numbers, 4 in each jaw.
- They have flat-edged surfaces.
- They are specialised in chewing food.
- There are a total of 12 molars in permanent dentition, 6 in each jaw.
- They are located at the back of the buccal cavity.
- They are specialised in chewing and grinding the food before it is swallowed.
The arrangement of teeth in the buccal cavity is called dentation. The teeth are arranged in the upper and lower jaw of the buccal cavity. The dentition of the teeth in the buccal cavity is as follows—
- The total number of milk teeth is 20.
- 10 milk teeth are arranged in each jaw.
- During the development of milk teeth, the last two molars in each jaw are absent.
- The total number of permanent teeth is 32.
- The upper jaw and lower jaw comprise 4 incisors, 2 canines, 4 premolars and 6 molars each.
- The last four molars situated on both the ends of the upper and lower jaws respectively usually develop between the ages of 17 to 21.
Structure of a tooth:
- The hard white part of the teeth visible in the buccal cavity is called the crown.
- It is made up of enamel which is the toughest substance in our body.
- The part of the tooth that is not visible and embedded inside the gum is called the root of the tooth.
- Enamel is followed by the layer of dentine below it.
- Dentine is comparatively soft than the tooth itself.
- The layer below the dentine, which forms the innermost layer, is called the pulp.
- Pulp is a soft layer embedded with blood vessels and nerves.
Taking care of our teeth:
- Brush the teeth twice a day and also floss them.
- Avoid eating too much sugar-rich foods.
- Visit a dentist for regular check-ups.
- Eat hard foods like raw and crunchy fruits and vegetables to exercise the teeth and gums.
- Include calcium-rich foods in your diet. Calcium helps in keeping the teeth strong.
- Clean your tongue regularly to remove germs.
- Tooth cavities are those regions on the teeth that have been eroded by the acid formed in the oral
The formation of acid occurs in the mouth due to bacterial action on the food that gets stuck between the teeth.
This phenomenon is also called tooth decay.
- Symptoms of tooth cavity include the following—
- Sensitivity to hot, cold and sour foods.
- Visibility of holes in the teeth.
- Brown and black stains on the crown of the teeth.
- Plaque is a yellow sticky layer formed on the top layer of a tooth.
- This layer is formed by the production of acid by digesting the sugars present in food.
This digestion is carried out by bacteria that survive on the food stuck between the teeth.
- The bacteria make pits and holes in the tooth enamel and slowly move to the inner layers.
- The pain in the tooth starts once the bacteria reach the pulp, which is embedded with blood vessels and nerves.
Buccal cavity: The cavity of the mouth; also called the oral cavity.
Voluntary muscles: The muscles attached to bones that help us move our body parts.
Mastication: The activity of crushing or grinding food by teeth.
Blood vessels: The tube-like structures through which blood flows through the tissues and organs.
Did You Know?
- Teeth comprise 96% of minerals and are harder than bones.
- In ancient times, people used twigs in place of toothbrushes to clean their teeth.
- The human mouth contains more bacteria than the total number of people on earth.
- Flossing helps in cleaning around 35% of the tooth surface.
- Only one-third portion of the tooth is visible in the buccal cavity, while the other two-thirds part is inside the gum.
- 90% of the diseases associated with the organ systems are related to tooth health.