Specific enteroendocrine cells of the stomach, called G cells, are stimulated by partially digested proteins, caffeine, and rising pH. When stimulated, G cells secrete

A. The voluntary phase of swallowing takes place within the mouth: The oral phase is under voluntary control and involves tongue movement to push the bolus to the oropharynx.
B. The epiglottis assists in propelling food into the trachea: This is incorrect. The epiglottis prevents food from entering the trachea by covering the glottis during swallowing; it does not propel food.
C. The involuntary portion of swallowing takes place in the pharynx: After the oral phase, swallowing becomes involuntary, involving reflexive contractions of pharyngeal muscles.
D. The mouth, pharynx and esophagus all take part in swallowing: All three structures are involved in the three phases of deglutition: oral, pharyngeal, and esophageal.

A. Lipolysis, glycogenolysis, beta oxidation: These refer to fat and glycogen metabolism, not the complete oxidation of glucose.
B. Glycolysis, citric acid (Krebs) cycle, electron transport chain, oxidative phosphorylation: This is the correct and complete pathway for glucose metabolism leading to ATP production.
C. Glycogenesis, lipogenesis, electron transport chain: Glycogenesis and lipogenesis are anabolic processes, not catabolic.
D. Gluconeogenesis, citric acid (Krebs) cycle, lipolysis: These are mixed pathways that do not directly represent glucose oxidation.