Q: The type of muscle fibres present in the wall of alimentary canal is:

Smooth muscle fibers or cells are elongated and spindle-shaped. The main function of these muscle fibers is peristalsis. It happens in the tubular viscera. That’s why smooth muscle fibers are present in the wall of the alimentary canal. The autonomous nervous system controls the action of these muscles. Thus, they are involuntary muscles.Thus, the correct answer is option A.

Q: Pick up the correct pairing.

\textbf{Correct answer: A} \textbf{Option (A):} \bullet Saliva is secreted in the mouth cavity from the salivary glands. There is salivary amylase present which helps in the digestion of starch. \bullet About 30% of the starch digestion occurs in the mouth with the help of salivary amylase. \bullet So, the mouth cavity is responsible for starting carbohydrate digestion. \textbf{Option (B):} \bullet Small intestine is the region in which digestion of all the nutrients takes place. \bullet This is because of the presence of pancreatic juice and the intestinal juice that contains the different enzymes for digestion. \bullet But water absorption takes place in the large intestine. \textbf{Option (C):} \bullet The pancreas is the region for the secretion of pancreatic juice containing different enzymes. \bullet Pancreatic juice also contains pancreatic lipase which helps with the digestion of fat in the small intestine. \bullet The pancreas is not the site for digestion as all the enzymes are released into the duodenum. \textbf{Option (D):} \bullet Liver is responsible for the secretion of bile. \bullet This helps with the emulsification of fat and facilitates the absorption of fat. Therefore the liver is not responsible for protein digestion in the system. Hence, the correct answer is option (A).

Question 1

In the wall of the alimentary canal, what is the correct sequence of layers, starting from the outside to the inside?

Accepted Answer

The alimentary canal walls have four basic tunics or layers. The outermost one is the serosa which is a thin membranous covering. Inner to serosa is the muscle layer of outer longitudinal muscles and the inner layer of circular&#10;muscles.Then&#10;there is&#10;submucosa which is then followed by the innermost layer of mucosa. The mucosa is the epithelial membrane lining the lumen of the alimentary canal.So, the correct answer is (C).

Question 2

The type of muscle fibres present in the wall of alimentary canal is:

Accepted Answer

Smooth&#10;muscle fibers or cells are elongated and spindle-shaped. The main&#10;function of these muscle fibers is peristalsis. It happens in the tubular viscera.&#10;That&#8217;s why smooth muscle fibers are present in the wall of the alimentary canal. The autonomous nervous system controls the action of these muscles. Thus, they are involuntary muscles.Thus, the correct answer is option A.

Question 3

What are the basic layers of the wall of alimentary canal?

Accepted Answer

The wall of alimentary canal possesses four layers- serosa, muscularis, sub mucosa, and mucosa. Serosa is the outermost layer and is made up of a thin mesothelium and connective tissue. Muscularis is formed by smooth muscles usually arranged into an inner circular and an outer longitudinal layer. Sub-mucosa layer is formed of loose connective tissues containing nerves, blood and lymph vessels. Glands are also present in sub-mucosa of duodenum. Mucosa is the innermost layer lining the lumen of the alimentary canal. Mucosa forms irregular folds (rugae) in stomach and villi in small intestine.

Question 4

Pick up the correct pairing.

Accepted Answer

extbf{Correct answer: A}   	extbf{Option (A):}   \bullet  Saliva is secreted in the mouth cavity from the salivary glands. There is salivary amylase present which helps in the digestion of starch.  \bullet  About 30% of the starch digestion occurs in the mouth with the help of salivary amylase.  \bullet  So, the mouth cavity is responsible for starting carbohydrate digestion.  	extbf{Option (B):}   \bullet  Small intestine is the region in which digestion of all the nutrients takes place.  \bullet  This is because of the presence of pancreatic juice and the intestinal juice that contains the different enzymes for digestion.  \bullet  But water absorption takes place in the large intestine.  	extbf{Option (C):}   \bullet  The pancreas is the region for the secretion of pancreatic juice containing different enzymes.  \bullet  Pancreatic juice also contains pancreatic lipase which helps with the digestion of fat in the small intestine.  \bullet  The pancreas is not the site for digestion as all the enzymes are released into the duodenum. 	extbf{Option (D):}   \bullet  Liver is responsible for the secretion of bile.  \bullet  This helps with the emulsification of fat and facilitates the absorption of fat. Therefore the liver is not responsible for protein digestion in the system. Hence, the correct answer is option (A).

Question 5

Enterokinase converts:

Accepted Answer

Enzymes are often produced in inactive forms called proenzymes. e.g. trypsinogen, pepsinogen, etc. Proenzymes are converted into active forms under specific conditions. For example, pepsinogen to pepsin and trypsinogen to trypsin. One of the important factors involved in the activation of trypsinogen to trypsin is enterokinase.

Question 6

The enzyme which hydrolyses starch to maltose is:

Accepted Answer

Hydrolases catalyse hydrolytic reactions. Some of the important hydrolases include amylases, sucrase, lactase, maltase, protease, esterase, etc. Amylase catalyses the hydrolysis of starch (polysaccharide form of glucose) into maltose (a disaccharide of glucose).

Question 7

Which of the following is a substrate of trypsin?

Accepted Answer

Trypsin is a protein-splitting enzyme, produced in the pancreas as an inactive protease trypsinogen. When it is secreted in the small intestine, it is activated by the intestinal enteropeptidase. Activated trypsin catalyses proteins into smaller peptides.Therefore, the correct answer is option A.

Question 8

Absorption of glycerol, fatty acids and monoglycerides takes place by:

Accepted Answer

Capillary walls contain an enzyme called lipoprotein lipase that dismantles the triglycerides in the lipoproteins into fatty acids and glycerol, thus enabling these to enter into the adipose cells.So, option A is the correct answer.

Question 9

Starting from the mouth, which enzymes are likely to act on the baked potato eaten by a man, as it moves down the alimentary canal?

Accepted Answer

Baked potatoes consist of starch which is a polysaccharide. In oral cavity, the food is mixed with saliva. The saliva contains an enzyme called salivary amylase (also called ptyalin) which converts starch into maltose, isomaltose and small dextrins. Salivary amylase is activated in the saliva by the chloride ions. The pancreatic juice (present in small intestine) contains starch digesting enzyme, called pancreatic amylase which converts starch into maltose, isomaltose and &#945;-dextrins.Hence, the correct answer is option B.

Question 10

Digested lipids are absorbed from lacteals as:

Accepted Answer

The products of the lipid digestion enter the body by a different process and different route. The monoglycerides and diglycerides are insoluble in water and cannot be directly absorbed from the intestinal content. They combine with the bile salts and phospholipids to form small, spherical, water soluble molecular aggregates called micelles.So, option A is the correct option.

Question 11

Describe the process of assimilation of food.

Accepted Answer

extbf{Solution: } 	extbf{Assimilation of Food}   \bullet  Assimilation of food is the process of accumulation of the nutrients inside the cell where the food molecules are metabolized or stored to provide energy to the cell.  \bullet  Digested food from the intestine is transported into the blood vessels or the lymph vessels. This acts as a transporter to move the absorbed nutrients from the intestine to the cells where the nutrient is stored.  \bullet   	extbf{Assimilation of Glucose:}  Glucose is the primary source of energy in the cell.  \bullet  Excess glucose gets stored in the liver and the muscle cells. It is stored in the form of glycogen which can be used for energy requirements when the level of glucose gets depleted in the body.  \bullet   	extbf{Assimilation of Fatty acid:}  Fatty acids that are absorbed through the intestine move into the lymph vessel which carries the fatty acids to the adipocyte cells.  \bullet  Fatty acids are stored in the adipocyte cells and based on the requirements they can be converted to glucose using gluconeogenesis.  \bullet   	extbf{Assimilation of Protein:}  Amino acids that are absorbed by the intestine are used in the generation of proteins inside the cells.  \bullet  The excess amino acids are converted to glucose in the liver with the generation of ammonia. This ammonia gets converted to urea inside the liver and is then removed from the body.

Question 12

Which of the following organs is responsible for storing excess bile produced by the liver?

Accepted Answer

The liver produces bile, which is stored in the gall bladder before entering the bile duct into the duodenumSo, the correct answer is 'Gall bladder'

Question 13

Which of the following statement is incorrect about the pancreas?

Accepted Answer

Each hepatic lobule of the liver is covered by a thin connective tissue sheath called the Glisson's capsule. So, the correct answer is (d).

Question 14

Name the following: The three salivary glands

Accepted Answer

The three salivary glands  are -Parotid gland, submandibular gland and  sublingual gland

Question 15

Duodenum has characteristic Brunner's glands, which secrete two hormones called:

Accepted Answer

Brunner's glands (or duodenal glands) are compound tubular submucosal glands found in the duodenum. Secretin is secreted in the duodenum in response to the acidic chyme entering the small intestine from the stomach. The primary target of secretin is the pancreas. Secretin stimulates the pancreas and bile ducts to release sodium bicarbonate to neutralize the acid. Cholecystokinin is secreted in the duodenum in response to partially digested fat and protein from the stomach. It stimulates the release of digestive enzymes in the pancreas and stimulates the contraction of the gall bladder to empty bile into the duodenum.

Question 16

Which part of the human body is affected during Jaundice?

Accepted Answer

Jaundice affects the liver.A yellow-orange substance is formed whenever the heme in haemoglobin is broken down and bile pigments are produced. These substances get filtered in the liver and are eliminated.If liver is unable to remove these pigments, they accumulate in the liver, causing the skin, nails, urine to turn yellow.Hence, the correct answer is option (C).

Question 17

A condition in which feaces are discharged from the bowel frequently and in liquid form is termed as:

Accepted Answer

Diarrhoea is the frequent passage of loose, watery, soft stools with or without abdominal bloating, pressure, and cramps. People of all ages can suffer from diarrhoea; it can be caused by viruses or bacteria. Most common symptom is watery, liquid stool. Along with this, there can be abdominal cramps, fever, bloating, dehydration. etc.Therefore, the correct answer is option B.

Question 18

When the direction of the peristaltic movements of the stomach and oesophagus is reversed, it causes:

Accepted Answer

Peristalsis pushes food through the lower oesophagus into the stomach. When the peristaltic movements of the stomach and oesophagus reverse their normal direction, it is called reverse peristalsis. In this situation, the contraction of abdominal muscles and diaphragm pushes food back through the oesophagus and out through mouth which results to vomiting. So, the correct option is C.

Question 19

If your diet does not contain enough roughage, then you are likely to suffer from:

Accepted Answer

Roughage or dietary fibre as it is known is the indigestible portion of the carbohydrate present in the food derived from plants.These are of two types, namely, the soluble fibres and the insoluble ones. The insoluble fibres are metabolically inert and being prebiotic, ferment in the large intestine. These bulking fibers tend to absorb water as they move through the digestive system which helps in easy defecation. Hence, consuming a diet without roughage will lead to constipation.

Question 20

Difficulty in digestion of food is called:

Accepted Answer

Difficulty in the digestion of food is called indigestion. It occurs as a symptom of gastroesophageal reflux disease, ulcers, or gall bladder disease. It causes abdominal pain, belching gas, nausea and vomiting.So, the correct answer is 'Indigestion'.

Question 21

Kwashiorkor develops due to:

Accepted Answer

Kwashiorkor is a type of malnutrition disorder caused by a severely inadequate amount of protein in the diet. It is also called 'protein malnutrition'.Symptoms include fatigue, diarrhoea, loss of muscle mass, failure to grow or gain weight, edema (swelling) of the ankles, feet, and belly, the compromised immune system, which can lead to more frequent and severe infections, and irritability.So, the correct answer is 'Malnutrition'.

Column 1	Column 2
Mouth	Certain drugs coming in contact with the mucosa of mouth and lower side of tongue are absorbed into the blood capillaries lining them.
Stomach	Absorption of water, simple sugar and alcohol takes place.
Small intestine	Glucose, fructose, fatty acids, glycerol and amino acids are absorbed through the mucosa into the blood stream and lymph.
Large intestine	Absorption of water, some minerals and drug takes place.

Digestion And Absorption