Final answer:
Glucose in the post-absorptive state comes from glycogenolysis, the breakdown of glycogen, and gluconeogenesis, the synthesis of glucose from non-carbohydrate sources. The correct answer is B) Glycogenolysis and gluconeogenesis.
Step-by-step explanation:
Sources of Glucose in the Post-Absorptive State
The sources of glucose during the post-absorptive state are not from the diet, as the post-absorptive state signifies a period where digestion and absorption of a meal have already been completed. Instead, the body must rely on other mechanisms to maintain blood glucose levels. The processes that supply glucose during this time are known as glycogenolysis and gluconeogenesis.
Glycogenolysis is the breakdown of glycogen into glucose, primarily taking place in the liver and, to a lesser extent, in the kidneys. This process serves as the initial response to declining blood glucose levels, as glycogen stores can be quickly mobilized. Gluconeogenesis, on the other hand, is the synthesis of glucose not from carbohydrates but from non-carbohydrate sources, such as lactate, glycerol, and gluconeogenic amino acids, mostly occurring in the liver and kidneys. This metabolic pathway becomes increasingly important as glycogen stores are depleted.
Therefore, the correct answer to which sources provide glucose during the post-absorptive state is B) Glycogenolysis and gluconeogenesis.