M5C14 Flashcards
(25 cards)
What is the role of the endocrine system in the body?
The endocrine system regulates body functions using hormones secreted directly into the bloodstream by endocrine glands.
Differentiate between endocrine and exocrine glands.
Endocrine glands: Secrete hormones directly into the bloodstream (e.g. pancreas).
Exocrine glands: Secrete substances through ducts (e.g.salivary glands)
What are the differences between steroid and non-steroid hormones?
Steroid hormones: Lipid-based pass through cell membranes.
Non-steroid hormones: Bind to cell surface receptors and use second messengers like cAMP to trigger responses.
What hormones are secreted by the adrenal cortex and adrenal medulla?
Adrenal cortex: Cortisol, aldosterone.
Adrenal medulla: Adrenaline and noradrenaline (non-steroid hormones involved in fight or flight response).
How does the pancreas function both as an endocrine and exocrine gland?
Endocrine: Islets of Langerhans (alpha and beta cells) release glucagon and insulin into the blood.
Exocrine: Releases digestive enzymes via ducts into the small intestine.
What stimulates insulin secretion and what does insulin do?
High blood glucose levels trigger insulin secretion. Insulin increases glucose uptake by cells and stimulates glycogenesis in the liver.
When is glucagon released and what is its function?
Glucagon is released when blood glucose levels are low. It stimulates glycogenolysis and gluconeogenesis.
How do insulin and glucagon regulate blood glucose levels?
Insulin: Lowers blood glucose by promoting uptake and storage.
Glucagon: Raises blood glucose by promoting breakdown and release of glucose.
What is the difference between Type 1 and Type 2 Diabetes?
Type 1: Autoimmune destruction of beta cells; no insulin production.
Type 2: Insulin resistance; often linked to lifestyle factors.
What is cell signaling in the context of hormonal communication?
It’s the process by which hormones interact with receptors to initiate a response in target cells.
What is the role of second messengers like cAMP in hormone signaling?
They amplify the signal from a hormone-receptor interaction initiating a larger cellular response.
What is the hormonal basis of the fight or flight response?
Adrenaline and noradrenaline from the adrenal medulla increase heart rate and respiration
What are the roles of alpha and beta cells in the pancreas?
Alpha cells: Secrete glucagon.
Beta cells: Secrete insulin.
What is the function of adenyl cyclase in cell signaling?
Adenyl cyclase converts ATP into cyclic AMP (cAMP) which acts as a second messenger to activate enzymes within the cell.
Describe the action of adrenaline on liver cells.
Adrenaline binds to receptors on liver cells activating adenyl cyclase
How does insulin affect hepatocytes (liver cells)?
Insulin stimulates hepatocytes to convert glucose to glycogen (glycogenesis) and increases glucose uptake from blood.
How does glucagon affect hepatocytes? Glucagon stimulates glycogenolysis (glycogen to glucose)
Glucagon stimulates glycogenolysis (glycogen to glucose), gluconeogenesis (new glucose from amino acids/fats)
How is blood glucose concentration regulated after a meal?
Blood glucose rises → detected by beta cells → insulin secreted → increased glucose uptake and glycogenesis → blood glucose returns to normal.
How is blood glucose concentration regulated during fasting?
Blood glucose falls → detected by alpha cells → glucagon secreted → increased glycogenolysis and gluconeogenesis → blood glucose returns to normal.
What causes Type 1 Diabetes and how is it treated?
Caused by autoimmune destruction of beta cells leading to no insulin production. Treated with insulin injections or pumps.
What causes Type 2 Diabetes and how is it managed?
Caused by insulin resistance and linked to obesity/lifestyle. Managed through diet, exercise
What is Gluconeogenesis:
Formation of glucose from non-carbohydrate sources.
What are the advantages and disadvantages of using genetically engineered bacteria to produce insulin?
Advantages: Human insulin (less allergy risk) = reliable.
Disadvantages: Requires sterile conditions and regulation.
What are the functions of the adrenal cortex hormones?
Cortisol: Increases blood glucose, suppresses immune response.
Aldosterone: Regulates Na+/K+ balance and blood pressure.
