Digestive System MCQ for RRB & SSC and other Competitive exams
51
The hepatic portal vein carries blood from which organ to the liver?
✓ Answer:
C
Intestines
The Hepatic Portal Vein carries nutrient-rich blood from the intestines, stomach, spleen, and pancreas to the liver. This allows the liver to process absorbed nutrients (glucose, amino acids) before they enter general circulation. This is the basis of the First Pass Metabolism concept.
52
Chymotrypsin is secreted by which organ?
✓ Answer:
C
Pancreas
Chymotrypsin is a proteolytic enzyme secreted by the pancreas as inactive Chymotrypsinogen, activated by Trypsin in the small intestine. It digests proteins by cleaving peptide bonds, specifically after aromatic amino acids (phenylalanine, tyrosine, tryptophan).
53
Which of the following is the primary site of fat digestion?
✓ Answer:
C
Small Intestine
Fat digestion primarily occurs in the small intestine (duodenum and jejunum). Bile emulsifies fat and Pancreatic Lipase breaks triglycerides into fatty acids and glycerol. Although a small amount of lingual lipase and gastric lipase act in the mouth and stomach, the small intestine is the major site.
54
Kupffer cells are found in which organ?
✓ Answer:
C
Liver
Kupffer cells are specialized macrophages (immune cells) found in the liver lining the sinusoids (liver capillaries). They phagocytose (engulf and destroy) bacteria, debris, old red blood cells, and foreign particles from the blood coming through the hepatic portal vein. They are part of the body's immune defense.
55
Which of the following is NOT a digestive enzyme found in pancreatic juice?
✓ Answer:
D
Rennin
Rennin is found in gastric juice of infants, NOT in pancreatic juice. Pancreatic juice contains: Pancreatic amylase (digests starch), Pancreatic lipase (digests fats), Trypsin and Chymotrypsin (digest proteins), Nucleases (digest nucleic acids), and Bicarbonate (neutralizes acid).
56
Which of the following is NOT a function of the liver?
✓ Answer:
B
Production of red blood cells in adults
In adults, red blood cells (RBCs) are produced in the Red Bone Marrow, NOT the liver. However, in the fetus, the liver is a site of RBC production. The liver synthesizes urea (from amino acid metabolism), plasma proteins (albumin, fibrinogen), and detoxifies harmful substances.
57
Which of the following is absorbed directly into the blood capillaries of the villi?
✓ Answer:
C
Glucose
Glucose and Amino acids are absorbed into blood capillaries of villi and transported to liver via hepatic portal vein. Fatty acids and Glycerol are reassembled into triglycerides and enter lacteals (lymph capillaries).
58
Which of the following is the end product of fat digestion?
✓ Answer:
C
Fatty acids and Glycerol
Fat digestion end products: Fats (Triglycerides) > Fatty Acids + Glycerol (by lipase). Carbohydrates > Glucose, Fructose, Galactose. Proteins > Amino Acids. These three are the final absorbable units of the three macronutrients.
59
Which part of the alimentary canal has the most acidic environment?
✓ Answer:
C
Stomach
The stomach has the most acidic environment with pH 1-2 due to HCl secretion by parietal cells. This is necessary for protein digestion and killing pathogens. The mouth is near neutral (pH 6.5-7.5), the small intestine is slightly alkaline (pH 7-8), and the large intestine is mildly acidic (pH ~5-7).
60
Which of the following describes the function of the rectum?
✓ Answer:
C
Temporarily stores faeces before defecation
The Rectum is the final section of the large intestine that temporarily stores faeces until defecation. When faeces fill the rectum, stretch receptors trigger the defecation reflex. Faeces are expelled through the anus, controlled by the internal and external anal sphincters.