- To perform various functions of the body, energy is required, which is obtained from food. The process of conversion of complex food material into simple and diffusible forms by hydrolysis is termed as Digestion. Human Digestive System
- All parts of the body are involved in the uptake and digestion of food along with the elimination of undigested material.
- The alimentary canal is mainly referred to as the pathway by which food enters our body and moves out through the anus after digestion. It is a tube-like structure that starts from the mouth and ends in the anus.
- The alimentary canal plays a primary role in human digestion and is also termed as the digestive tract.
The alimentary canal is divided into the following parts:
- Mouth and Buccopharyngeal cavity
- Small Intestine
- Large Intestine
➢ Mouth and Buccopharyngeal Cavity
The mouth is also called the buccal cavity or the oral cavity. In the human digestive system mouth is the upper end or the beginning of the alimentary canal, which leads to the pharynx and to the oesophagus.Mouth
In humans, both the mouth or the buccal cavity and the nasal cavity are separated by the palate. The buccal cavity mainly comprises the primary organ of the digestive system including the teeth, tongue and salivary glands.
The mouth is an opening through which the food is taken inside the body. It is bounded by lips and its inner parts comprise of the cheeks, tongue, upper jaw and lower jaw.
- The upper jaw is fixed, which forms the roof of the mouth cavity and consists of palate, teeth, and gums surrounding the teeth. The lower jaw is movable and forms the floor of the mouth cavity, which consists of the tongue along with the teeth and gums surrounding them.
- The mouth plays an important role in speech, helps in breathing in certain cases, when the nose is blocked and during strenuous exercise. It is also the most important part of the human body, which permits us to enjoy the food we eat and also to communicate with the rest of the world.
The mouth or the oral cavity comprises of two parts:
(i) The oral cavity proper: It mainly comprises of the tongue.
(ii) The oral vestibule: It is the slit-like space between the teeth and the buccal cavity and between the lips and cheeks.
► Different Parts of the Buccal Cavity
- Lips are the soft, muscular and movable structures, which are formed by the complex of orbicularis oris muscles.
- The reddish-pink appearance of the lips is mainly because of the underlying blood vessels which are covered by the thin and transparent epithelium tissues.
- It is a large, muscular organ, which occupies most of the oral cavity and can take up a variety of shapes and positions.
- There are 50 to 100 taste receptor cells in each taste buds, which are located in the lining of the mouth.
It is the main sense organ of human beings and is involved in:
- Sense of taste.
- A major organ of speech.
- Oral cleansing of the mouth.
- Squeezing food into the oropharynx while swallowing.
- Formation of clear and distinct sound during the speech.
(iii) Buccal mucosa
- It is the inner lining of the cheeks and the back of the lips. It provides a round shape to the cheeks.
Question 1:This is a muscular organ in the mouth that helps position the food between the teeth and is covered in nerve endings that allow us to taste our food.
- The teeth are the strongest and rigid substances in the human body. A normal adult has 32 teeth and is divided into incisor, canine, molars and premolars. There is a third molar, which is called the wisdom teeth, which appear in a person’s late teens or early twenties.
Question 2:How many types of teeth are present in an adult?
Permanent teeth in an adult are of 4 types. They are incisors, canines premolars and molars.
- Each tooth consists of a crown with one or more tips, a neck, and a root. The Pulp cavity is the centre part of the tooth, filled with blood vessels, nerves and connective tissues and is surrounded by an enamel, which protects the tooth against scratch, cut and from the invasion of bacteria present in the mouth.