With respect to the sub-mucosal layer of the alimentary canal, which of the following statements are correct?
I. It is formed of loose connective tissues containing nerves, blood, and lymph vessels. II. In the duodenum, glands are present in the sub-mucosal layer. III. Brunner's glands are mucosal glands that extend into the muscularis layer. IV. Sub-mucosal glands help in secreting pepsinogen in the stomach.
Explanation: Statements I and II are correct. The sub-mucosa consists of loose connective tissue containing nerves, blood vessels, and lymph vessels. Brunner's glands are present in the sub-mucosa of the duodenum. Statement III is incorrect because Brunner's glands are sub-mucosal glands, not mucosal glands. Statement IV is incorrect because pepsinogen is secreted by chief cells of the gastric mucosa.
Question 62 of 100
📘 CLASS XI
Read the following statements regarding mucosal modifications in the human stomach and small intestine:
I. The mucosal layer forms irregular folds called rugae in the stomach. II. It forms small finger-like foldings called villi in the small intestine. III. Crypts of Lieberkuhn are mucosal glands formed in between the bases of villi in the intestine. IV. Gastric glands are sub-mucosal glands that secrete mucus.
Explanation: Statements I, II, and III are correct. The stomach mucosa forms rugae, while the small intestine has villi and Crypts of Lieberkuhn. Statement IV is incorrect because gastric glands are mucosal glands, not sub-mucosal glands.
Question 63 of 100
📘 CLASS XI
Evaluate the following statements regarding the structural adaptations of intestinal villi for absorption:
I. The cells lining the villi produce numerous microscopic projections called microvilli, giving a brush border appearance. II. These brush border modifications increase the surface area enormously. III. Villi are supplied with a network of capillaries and a large lymph vessel called the lacteal. IV. Lacteals absorb amino acids and simple sugars, while blood capillaries absorb fatty acids.
Explanation: Statements I, II, and III are correct. Microvilli form the brush border and greatly increase the absorptive surface area. Each villus contains blood capillaries and a central lacteal. Statement IV is incorrect because lacteals absorb fats in the form of chylomicrons, whereas amino acids and monosaccharides enter the blood capillaries.
Question 64 of 100
📘 CLASS XI
Identify the correct set of statements regarding salivary gland secretions and locations:
I. Saliva is mainly produced by three pairs of salivary glands situated just outside the buccal cavity. II. The parotid glands are located in the cheek region. III. The sub-maxillary/sub-mandibular glands are located at the lower jaw. IV. Sub-lingual glands are situated below the tongue and open into the stomach directly.
Explanation: Statements I, II, and III are correct because the three pairs of salivary glands are situated just outside the buccal cavity. The parotid glands lie in the cheek region, the sub-maxillary (sub-mandibular) glands are located at the lower jaw, and the sub-lingual glands are situated below the tongue. Statement IV is incorrect because the sub-lingual glands open into the buccal cavity, not the stomach.
Question 65 of 100
📘 CLASS XI
Read the statements regarding the human liver and select the correct combination:
I. The liver is the largest gland of the body, weighing 1.2 to 1.5 kg in an adult human. II. The hepatic lobules are the structural and functional units of the liver. III. The hepatic cells in each lobule are arranged in the form of cords. IV. Glisson's capsule is a thin connective tissue sheath covering each hepatic lobule.
Explanation: All statements are correct. The liver is the largest gland in the human body, weighing about 1.2 to 1.5 kg. Its structural and functional units are the hepatic lobules, where hepatocytes are arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called Glisson's capsule.
Question 66 of 100
📘 CLASS XI
Assess the statements regarding the human bile duct system and pancreas anatomy:
I. The bile secreted by hepatic cells is stored and concentrated in a thin muscular sac called the gall bladder. II. The cystic duct of the gall bladder along with the hepatic duct from the liver forms the common bile duct. III. The common bile duct and pancreatic duct open together into the duodenum as the common hepato-pancreatic duct. IV. The opening of the common hepato-pancreatic duct is guarded by the sphincter of Oddi.
Explanation: All statements are correct. Bile secreted by hepatic cells is stored and concentrated in the gall bladder. The cystic duct joins the hepatic duct to form the common bile duct, which unites with the pancreatic duct to form the common hepato-pancreatic duct. Its opening into the duodenum is guarded by the sphincter of Oddi.
Question 67 of 100
📘 CLASS XI
Evaluate the statements regarding the dual nature of the pancreas and its secretions:
I. The pancreas is a compound gland containing both exocrine and endocrine portions. II. It is an elongated organ situated between the limbs of the 'C' shaped duodenum. III. The exocrine portion secretes an alkaline pancreatic juice containing inactive enzymes. IV. The endocrine portion secretes proteolytic hormones like pepsin and trypsin into the blood.
Explanation: Statements I and III are correct. The pancreas is a compound gland with exocrine and endocrine parts. Its exocrine portion secretes alkaline pancreatic juice containing inactive zymogens. Statement II is incorrect according to the NCERT description used here because the pancreas lies between the limbs of the 'U' shaped duodenum. Statement IV is incorrect because the endocrine pancreas secretes hormones such as insulin and glucagon, not proteolytic enzymes.
Question 68 of 100
📘 CLASS XI
Which of the following statements about digestion in the buccal cavity is/are correct?
I. The buccal cavity performs mastication of food and facilitation of swallowing. II. Mucus in saliva helps in lubricating and adhering the masticated food particles into a bolus. III. The bolus is conveyed into the pharynx and then the oesophagus by swallowing (deglutition). IV. Saliva contains electrolytes and enzymes: salivary amylase and lysozyme.
Explanation: All statements are correct. The buccal cavity performs mastication and facilitates swallowing. Salivary mucus lubricates food and forms a bolus, which is swallowed through the pharynx into the oesophagus. Saliva contains electrolytes, salivary amylase, and the antibacterial enzyme lysozyme.
Question 69 of 100
📘 CLASS XI
Assess the statements regarding starch digestion in the human oral cavity and select the correct option:
I. The chemical process of digestion is initiated in the oral cavity by salivary amylase. II. About 30 percent of starch is hydrolysed in the oral cavity by salivary amylase. III. The optimum pH for the activity of salivary amylase is 1.8. IV. Salivary amylase digests starch into simple monosaccharides like glucose.
Explanation: Statements I and II are correct because salivary amylase initiates digestion in the mouth and hydrolyses about 30% of starch. Statement III is incorrect because the optimum pH for salivary amylase is 6.8, whereas pH 1.8 is optimal for pepsin. Statement IV is incorrect because salivary amylase converts starch into maltose, not glucose directly.
Question 70 of 100
📘 CLASS XI
Read the following statements about gastric juice cells and secretions and identify the correct combination:
I. Mucus neck cells secrete mucus which helps in lubricating the mucosal epithelium. II. Peptic or chief cells secrete the active proteolytic enzyme pepsin directly. III. Parietal or oxyntic cells secrete HCl and intrinsic factor. IV. Intrinsic factor secreted by parietal cells is essential for the absorption of vitamin B12.
Explanation: Statements I, III, and IV are correct. Mucus neck cells secrete mucus, while parietal (oxyntic) cells secrete hydrochloric acid and intrinsic factor required for vitamin B12 absorption. Statement II is incorrect because chief cells secrete inactive pepsinogen, not active pepsin.
