ORAL CAVITY (THE MOUTH)
The alimentary canal begins with the oral cavity or the mouth.
The major parts of the oral cavity are:
- Cheeks: They form the walls of the oval-shaped oral cavity.
- Lips: They surround the opening to the oral cavity.
- Hard palate: It forms the anterior portion of the roof of the mouth.
- Muscular soft palate: It lies posterior to the roof of the mouth.
- Uvula: It is a small soft tissue hanging from the soft palate that aids in producing sounds and speech.
- Tongue: It extends along the floor of the oral cavity and muscles attach it to the lower jaw bone. It moves food around during mastication and deglutition.
- Papillae: These are small raised areas on the tongue that contain the taste buds, which are sensitive to the chemical nature of the food.
- Tonsils: These are masses of lymphatic tissue located in depressions of the mucous membranes on both sides of the oropharynx (part of throat near the mouth)
- Gums: They are made of fleshy tissue and also surround the sockets of the teeth.
- Teeth: They are the set of hard, bony, enamel-like structures in the jaws, used for biting and chewing.
PHARYNX OR THROAT
The pharynx or throat is a muscular tube, about 5 inches long lined with mucous membranes.
It serves as a common passage for air travelling from the nose to the windpipe i.e. trachea and helps food travel from the oral cavity to the esophagus.
When swallowing of food occurs, a flap of tissue, the epiglottis covers the trachea so that the food does not pass into the trachea.
The oesphagus/esophagus or the food pipe is a 9- or 10- inch long muscular tube extending from the pharynx to the stomach.
It performs peristalsis, which means propelling food towards the stomach with the help of rhythmic contractions of the muscles in the walls of the esophagus.
It is an internal organ where the first part of the digestion occurs. It is a pear-shaped enlargement of the alimentary canal linking the esophagus to the small intestine. It is divided into:
- An upper portion called the fundic.
- A middle section known as the body.
- A lower portion which is known as the pylorus.
Q.1. Which amongst these is the lymphatic tissue?
Q.2. Esophagus is:
- 7- to 8- inches long
- 8- to 9- inches long
- 9- to 10- inches long
- 10- to 11- inches long
Q.3. At the time of swallowing, ____ it gets covered.
Q.4. Oropharynx is:
- Part of throat near food pipe.
- Part of throat near mouth.
- Part of stomach near esophagus
- Part of throat near tonsils
Q.5. Stomach contains:
Q.6. Uvula aids in producing:
Q.7. Papillae contain:
- Taste buds
- Parotid gland