Which of the following is not an accessory organ

Correct Answer: C

Rationale: The correct answer is C: esophagus. An accessory organ is one that aids in digestion but is not part of the digestive tract. The esophagus is part of the digestive tract, responsible for transporting food from the mouth to the stomach. The pancreas, liver, and gallbladder are all accessory organs as they play a role in digestion but are not directly part of the digestive tract. Pancreas produces enzymes for digestion, liver produces bile for fat digestion, and gallbladder stores and releases bile. Therefore, the esophagus is the correct answer as it is not an accessory organ.

Correct Answer: D

Rationale: The correct answer is D: cuspids. Cuspids, also known as canines, are pointed teeth that are specifically adapted for tearing and shredding food. They have long, sharp points that help in grasping and cutting food. Incisors (A) are flat-front teeth used for cutting and biting. Bicuspids (B) are premolars with two cusps used for grinding food. Molars (C) are large, flat teeth at the back of the mouth used for grinding and chewing. Therefore, D is the correct answer as cuspids are the pointed teeth adapted for tearing and shredding.

Correct Answer: D

Rationale: The correct answer is D because Plicae Circularis and intestinal villi increase the surface area of the small intestine mucosa, aiding in absorption. Plicae Circularis are circular folds in the mucosa, while intestinal villi are finger-like projections. This increased surface area allows for more efficient absorption of nutrients. A: Incorrect. Plicae Circularis and intestinal villi do not produce new cells for the mucosa. B: Incorrect. These structures do not carry products of digestion that won't pass through blood capillaries. C: Incorrect. They do not produce hormones to aid in digestion. In summary, choice D is correct as Plicae Circularis and intestinal villi primarily function to increase the surface area of the small intestine mucosa, aiding in absorption of nutrients.

Correct Answer: D

Rationale: Step 1: The cephalic phase occurs before food enters the stomach, triggered by the sight, smell, or thought of food. Step 2: The vagus nerve sends signals to the stomach to prepare for food digestion during this phase. Step 3: Increased flow of action potentials along the vagus nerve stimulates gastric glands to secrete gastric juice. Step 4: Therefore, choice D is correct as it accurately describes the physiological response during the cephalic phase. Summary: Choices A and B are incorrect as they do not align with the physiological processes during the cephalic phase. Choice C is incorrect because distention of the stomach triggers the gastric phase, not the cephalic phase.

Correct Answer: C

Rationale: The correct answer is C: stomach. The stomach has 3 layers of smooth muscle in its muscularis externa, which help in mixing and churning food for digestion. The small intestine (A) has 2 layers of smooth muscle, the esophagus (B) has skeletal and smooth muscle, and the large intestine (D) has outer longitudinal and inner circular layers of smooth muscle, not 3 distinct layers like the stomach.