Assertion: Secretin is released into circulation in response to low duodenal pH.
Reason: Secretin primarily functions to neutralize the pH in the duodenum, allowing digestive enzymes from the pancreas to function optimally.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Assertion: The muscularis externa of the stomach is unique from other organs of the gastrointestinal tract.
Reason: It does not have the Auerbach’s or myeneteric plexus.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach.
Reason: It acts on enterochromaffin like cells that release histamine which stimulates the parietal cells.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: The defining sign of kwashiorkor in a malnourished child is pitting edema (swelling of the ankles and feet).
Reason: Kwashiorkor is inadequate energy intake in all forms, including protein.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: The active absorption of calcium in the intestine requires the presence of Vitamin D.
Reason: Vitamin D is activated in kidney under the influence of parathyroid hormone.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: One serious side effect of a vagotomy[cutting of vagus nerve] is a vitamin B₁₂ deficiency later in life that is similar to pernicious anemia.
Reason: The vagus normally stimulates the stomach's parietal cells to secrete acid and intrinsic factor.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Constipation can be caused or exacerbated by a low-fiber diet, low liquid intake, or dieting.
Reason: Dietary fiber helps to decrease colonic transport time, increases stool bulk but simultaneously softens stool.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Consider the following statements regarding human alimentary canal:
I. Human dentition is thecodont, homodont and diphyodont
II. The tongue is freely movable muscular organ attached to the roof of the oral cavity by the frenulum
III. The opening of the stomach into the duodenum is guarded by the cardiac sphincter
The incorrect statements include:

The structural and functional units of liver are:
1. The four hepatic lobes containing the hepatic sinusoids lined by kupffer cells
2. The hepatic lobules containing hepatic cells arranged in the form of cords
3. The porta hepatis which carries the common bile duct and common hepatic artery, and the opening for the portal vein.
4. The right and the left lobes separated by the falciform ligament

Bile pigments help in:
1. Emulsification of fats
2. Absorption of the end products of fat digestion
3. Hydrolysis of fats
4. They do not play any role in fat metabolism or digestion