Digestion and Absorption Test - 46

The small intestine is the most important part of the digestive system where digestion and absorption of nutrients take place. The small intestine in adults is a long and narrow tube about 7 meters (23 feet) long. The large intestine is so called because it is wide in diameter as compared to the small intestine. The small intestine can be divided into 3 major regions such as duodenum, jejunum, and ileum.

The one whose diet is deficient in proteins is suffering from kwashiorkor. The symptoms of this include, edema or swelling (of face), change in skin and hair color, fatigue, diarrhoea, irritability.
Therefore, the correct answer is option A.

The small intestine in adults is a long and narrow tube about 7 meters (23 feet) long. The large intestine is so called because it is wide in diameter. However, it is shorter than the small intestine - only about 1.5 meters (5 feet) long. 

Gastric acid is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl) 0.05–0.1 M (roughly 5,000–10,000 parts per million) potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes break down the long chains of amino acids. The highly acidic environment in the stomach lumen causes proteins from food to lose their characteristic folded structure (or denature). This exposes the protein's peptide bonds. The gastric chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen, and in infancy rennin). Hydrochloric acid activates pepsinogen into the enzyme pepsin, which then helps digestion by breaking the bonds linking amino acids, a process known as proteolysis. In addition, many microorganisms have their growth inhibited by such an acidic environment, which is helpful to prevent infection. HCl is digestive juice. Fatty acids are digested by bile acids.

Parietal cells in the mucosa are found in the inner lining of the stomach which secrete hydrochloric acid (HCl) into the stomach lumen, or cavity. It decreases the pH of the stomach and has corrosive nature hence can harm the stomach wall. The gastric juice consists mucous also. It gets deposits on the inner wall of the stomach to protect it from the corrosiveness of HCl.

Many microbes present in alimentary canal of some animals like cones help in digestion and absorption of food. Bacteria in our large intestine helps in bowel movement.

Parotid salivary glands are present in the angle between two jaws. The parotid gland is a salivary gland, responsible for making saliva. There are two parotid glands, one on each side of the face. They are located in front of the ears and extend to the lower borders of the jawbones. The glands secrete the saliva which travels into the mouth to aid in chewing and digesting food. 

• The inner lining of the small intestine contain tiny finger like projections called Villi. These greatly increase the inner surface area for absorption of digested food.
• The surface of these villi are well supplied with a network of thin blood vessels, through which glucose and amino acids are passed into the bloodstreams. And fats are passed through specialised tubes called lymphatic vessels.
• Thus, Option C is correct.

Diarrhoea is a disease caused by the virus like norovirus and bacteria like clostridium, salmonella. It is characterised by the frequent passing of loose or watery stools. Common symptoms of diarrhoea include skin tenting, abdominal pain, nausea, dehydration, cramping, fever and bloody stools. Hence option A is correct.