Metabolism & Energy Balance

These flashcards cover key vocabulary and concepts associated with metabolism, energy balance, and hormone regulation, especially focused on insulin and glucagon's roles within fed and fasted states.

Insulin

A hormone produced by the β cells of the pancreatic islets that promotes glycogenesis, lipogenesis, and protein synthesis while preventing hyperglycemia.

Glucagon

A hormone produced by the α cells of the pancreatic islets that promotes glycogenolysis, gluconeogenesis, and ketone production while preventing hypoglycemia.

Fed-state

The state following food intake where nutrient storage and insulin release are stimulated by elevated levels of glucose and amino acids.

Fasted-state

The state occurring after food has been digested and absorbed, characterized by nutrient release and glucagon secretion to increase blood glucose.

GLUT4 transporters

Insulin-dependent glucose transporters that facilitate glucose uptake in adipose tissue and skeletal muscle.

Incretins

Digestive hormones released from the intestine in response to food that enhance insulin secretion from pancreatic β cells.

Glycogenesis

The process of converting glucose to glycogen for storage, primarily occurring in the liver and muscles.

Gluconeogenesis

The metabolic pathway that results in the generation of glucose from non-carbohydrate substrates during the fasted state.

Type I diabetes mellitus

A form of diabetes where the pancreas produces little to no insulin due to autoimmune destruction of β cells.

Type II diabetes mellitus

A form of diabetes characterized by insulin resistance and often associated with normal or elevated plasma insulin levels.

Polydipsia

Excessive thirst, often a symptom of diabetes due to increased plasma osmolarity.

A1C test

A test that measures the average blood glucose levels over the past 2-3 months by assessing glycated hemoglobin.

Feedforward system

A physiological response that anticipates a change and prepares the body for it, as seen with incretins during feeding.

Lipogenesis

The metabolic formation of fat from glucose and other substrates, occurring particularly during the fed-state.

Negative feedback control

A regulatory mechanism in which an increase in a product inhibits its production, maintaining homeostasis.

Epinephrine

A hormone that, when released during stress, can inhibit insulin action and promote the release of glucagon.