Ingestion of food - class-X

Most of our foods are complicated chemical structure.
In order to be absorbed and utilized by the body, they
must be broken down into relatively simple molecules.
The process by which the complex food materials are
changed to simple molecules is called digestion.

Epiglottis stands open during breathing, allowing air into the larynx. During swallowing it closes to prevent aspiration, forcing the swallowed liquids or food to go into the esophagus instead. It is thus the structure that diverts passage air into  the trachea and food into the esophagus

Succus entericus, or intestinal juice, contains enzymes that function optimally in an alkaline environment, which is maintained by secretions from Brunner's glands and the pancreas.

• Variables considered with feeding rate and gastric evacuation time includes temperature, season, activity, body size, gut capacity, satiety, and metabolic rate. 
• Gastric emptying rate declines more or less exponentially with time. Larger meals first are digested at a faster rate than small meals and the amount of pepsin and acid produced was somewhat proportional to the degree of distension of the stomach.
•  Stomach mobility often increases with the degree of stomach distension also. Gastric emptying time is approximately 3 - 4 hours.

Deglutition is the medical term for the act of swallowing, which involves the movement of food from the mouth through the pharynx and esophagus to the stomach.

Enterokinase is an enzyme secreted by the intestinal mucosa that activates trypsinogen into trypsin, making it a component of intestinal juice.

Micelles are small spherical aggregates formed by bile salts and fatty acids/monoglycerides, which facilitate the transport of lipids to the intestinal absorptive cells.

Succus entericus is the collective term for the secretions of the intestinal glands (brush border cells) and goblet cells in the small intestine.

Intrinsic factor is a glycoprotein produced by the parietal cells, also known as oxyntic cells, of the gastric mucosa and is essential for the absorption of vitamin B12.

Deglutition (swallowing) is a complex process that begins as a voluntary action in the mouth before becoming an involuntary reflex in the pharynx and esophagus.

Beaumont recognized that he had in St. Martin an unusual opportunity to observe digestive processes. Dr. Beaumont began to perform experiments on digestion for the first time using the stomach of St. Martin. He is known as father of gastric physiology.

The correct answer is (d).

The epiglottis is a flap of cartilage that covers the glottis during swallowing to prevent food from entering the trachea; failure of this mechanism leads to coughing.