Alimentary Canal
The tube extending from the mouth to the anus in which food intake, digestion, absorption and excretion of undigested food takes place is called alimentary canal or alimentary canal. The different parts of the alimentary canal are mouth, pharynx, esophagus, stomach, small intestine, colon and anus.
Mouth
 1. The face is located below the nose in the front of the human head. The mouth has two parts namely—
(1) Vestibule: It is transversely located orifice. It is surrounded by lips. Its interior is surrounded by gums and teeth.
: Functions of vestibule: With vestibule
We take food.
(II) Buccal cavity: It is the internal extension of the mouth. The parts of the mouth are the palate, tongue and teeth.
(a) Palate: The roof of the mouth is called the palate. Its front is called hard palate or hard palate and the back is called soft palate or soft palate. The hard palate has numerous transverse ridges. They are called rugae. The soft palate does not have ridges. At the end of the soft palate is a small fleshy flap or uvula.
(b) Tongue: Tongue is human’s sense of taste. The tongue is in the mouth
located on the floor. It is the lingual frenulum on the floor.
It is attached with a fold. The tongue is divided into two parts by an inverted ‘V’ shaped groove sulcus terminalis, namely the anterior oral part and the posterior pharyngeal part. The tip of the sulcus terminalis extends posteriorly and a
Marked by a small hole, called the foramen caecum. Numerous small projections can be seen on the surface of the tongue, called papillae.
The tongue has four types of papillae, namely-
(i) Circumvallate papillae: 10-12 in number. These are the largest of the four types of papillae. Each papilla contains 100 taste buds. They are at the back of the tongue, ‘V’ shaped.
(ii) Filiform papillae: largest in number and smallest. They are located towards the center of the tongue. These papillae do not contain taste receptors, instead they contain tactile receptors. They are also called conical (conical) papilli. They are primary.
(iii) Fungiform papillae (Fungiform pa- not pillae): These are smaller than vallate but larger than filiform. These papillae are mushroom shaped and located on the tip of the tongue. It contains sweet taste. They are red in color because they are full of blood cells.
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(iv) Foliate papillae: These are located on both sides of the base of the tongue and look like leaves. It does not contain flavoring.
â– Taste areas of tongue: Taste areas on the surface of the tongue can sense various tastes. The tongue has sweet taste buds at the front, bitter taste buds at the back and sour and salty taste buds on both sides respectively. on vivo Almera
Functions
1. The main function of the tongue is to taste. Also can feel touch, cold and hot. 2. Chewing and swallowing food
helps 3. Saliva helps to mix the food while chewing the food. 4. Helps to speak.
Teeth:
â– Characters: Human teeth are diphydont, thecodont and heterodont in nature.
(i) Diphidont teeth: Humans have two sets of teeth, milk teeth and permanent teeth. Milk teeth appear at the age of six-months and are 20 in number. Baby teeth fall out when the child is six years old. The teeth that erupt next are the permanent teeth, 32 in number. Eruption of permanent teeth ends between the ages of 18-25 years.
(ii) Thecodont teeth: Human teeth are set in unstable sockets in the jaws.
(iii) Heterodont teeth: Humans have different types of teeth, ie incisors: 2 in each half of each jaw, total 4. These teeth help in cutting food. Canine: The pointed tooth next to the incisor. 1 in each half of each jaw for a total of 4. Used for cutting and tearing. Premolar: The next tooth of the canine. Each jaw has 2 in each half for a total of 4. Molar: The tooth next to the premolar. A total of 12 teeth make up each half of each jaw. The third molar of a human is called wisdom teeth. Premolars and molars help in chewing food.