Human Digestive System

The anterior end of the stomach is situated near the diaphragm,  which is right beneath the heart and that is the reason why it is branded as the Cardiac Stomach. Hastate plate makes the mid-ventral floor of cardiac stomach.

Liver does not secretes any enzyme. Bile juice is produced here.

Stem cells are specialised cells which are capable of cell division to replace dead cells. In the gastrointestinal tract, these cells are essential to replenish the surface epithelium.

Bile is a bitter tasting, dark green to yellowish brown fluid produced by the liver of most vertebrates. It is secreted by the liver, stored in the gallbladder and discharged into the duodenum. It is a composition of water, bile salts, mucus and pigments, fats, inorganic salts and cholesterol.

Dubin-Johnson syndrome is a conjugated hyperbilirubinemia caused by defective transport of conjugated bilirubin into the bile canaliculi. The defect is in the MRP2 (multidrug resistance-associated protein 2) transporter, not in UDP glucuronyl transferase (which is deficient in Crigler-Najjar syndrome) or hepatic uptake (defective in Rotor syndrome). The liver appears black due to melanin-like pigment deposition.

This is given wrong as it is the opposite. It actives pepsinogen to its active form pepsin.

Duodenum is correct as it is the site where neutralisation of acidic chyme occurs with bicarbonate ions.

Ptyalin acts on boiled starch only.

The heart is part of the circulatory system, not the digestive system. The digestive system includes the mouth, stomach, liver (which produces bile), intestines, and other organs that process food. The heart pumps blood and has no direct role in digestion.

This is the correct option as zymogen cells are responsible for secreting a proenzyme of protein digestive enzyme called pepsiogen.

Nutrition involves processes that provide nutrients to the body: ingestion (taking in food), digestion (breaking down food), absorption (taking nutrients into blood), and assimilation (using nutrients). Excretion removes waste products and is not part of the nutrition process.

The liver produces bile, small intestine produces intestinal enzymes, and stomach produces gastric juices. The oesophagus is a muscular tube that only transports food via peristalsis - it does not secrete any digestive juices.

While digestion begins in the mouth and continues in the stomach, most enzymatic breakdown completes in the small intestine where pancreatic enzymes and intestinal juices finish breaking down proteins, carbohydrates, and fats.

The alimentary canal anatomically ends at the anus, but the rectum is the final storage chamber before elimination. The colon precedes the rectum, while the small intestine connects to the large intestine at the caecum.

Mastication is the scientific term for chewing - the mechanical breakdown of food by teeth. It increases surface area for enzymes to act, unlike ingestion (taking in), secretion (producing juices), or assimilation (absorbing nutrients).