5 Questions
What is the primary function of glucagon in the regulation of blood glucose levels?
Stimulating hepatic glycogenolysis and gluconeogenesis
Which hormone assumes a critical role in hypoglycemia when glucagon secretion is deficient?
Epinephrine
What is the effect of epinephrine on insulin secretion and uptake?
Inhibits insulin secretion and inhibits insulin uptake
What is the role of the hypothalamic glucoreceptors in response to hypoglycemia?
Triggering the secretion of catecholamines and ACTH
What is the term used to describe the hormones that oppose the action of insulin on glucose use?
Counterregulatory hormones
Study Notes
Glucoregulatory Systems
- Humans have two overlapping glucose regulating systems that are activated by hypoglycemia:
- Pancreatic α cells releasing glucagon
- Hypothalamic receptors responding to low blood glucose concentrations
- Hypothalamic glucoreceptors trigger:
- Catecholamine secretion
- ACTH and growth hormone release from the anterior pituitary
- ACTH increases cortisol synthesis and secretion in the adrenal cortex
Counterregulatory Hormones
- Glucagon, catecholamines, cortisol, and growth hormone counteract insulin's action on glucose use
- Function:
- Glucagon: stimulates hepatic glycogenolysis and gluconeogenesis
- Epinephrine:
- Promotes glycogenolysis and lipolysis
- Inhibits insulin secretion and insulin-mediated glucose uptake in peripheral tissues
- Cortisol and growth hormone: involved in long-term transcriptional management of glucose metabolism
Hypoglycemia
- Types of hypoglycemia:
- Insulin-induced hypoglycemia (frequent in diabetes patients receiving insulin treatment)
- Postprandial (reactive) hypoglycemia
- Fasting hypoglycemia
- Alcohol-related hypoglycemia
- Treatment of insulin-induced hypoglycemia:
- Mild cases: oral administration of carbohydrates
- Unconscious patients: subcutaneous or intramuscular glucagon administration
This quiz covers the two overlapping glucose regulating systems in humans, including the pancreatic α cells and hypothalamic glucoreceptors. It also explores the role of these systems in responding to hypoglycemia and regulating blood glucose levels.
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