Antagonistic Hormones Flashcards

Questions and Answers

Where are insulin and glucagon secreted from?

pancreas

What do insulin and glucagon do?

manage blood glucose levels

What does insulin do?

Insulin is secreted when glucose levels in the bloodstream are high as it lowers glucose levels.

What does glucagon do?

Glucagon is secreted when glucose levels in the bloodstream are low as it raises glucose levels. Signup and view all the answers

What types of cells secrete insulin?

beta cells Signup and view all the answers

What are Islets of Langerhans?

clusters of beta cells which make insulin Signup and view all the answers

Is insulin water-soluble or fat-soluble?

water-soluble Signup and view all the answers

How does insulin lower the blood glucose levels?

Insulin binds to muscular or liver cells, stimulating them to absorb glucose from the bloodstream. Signup and view all the answers

What cells does insulin bind to?

muscular and liver cells Signup and view all the answers

What are antagonistic hormones?

Hormones that have opposing effects Signup and view all the answers

What is the feedback loop of insulin and glucagon?

Both act as negative feedback loops to regulate glucose levels in the blood. Signup and view all the answers

What types of cells secrete glucagon?

alpha cells Signup and view all the answers

Is glucagon water-soluble or fat-soluble?

water-soluble Signup and view all the answers

How does glucagon raise the blood glucose levels?

Glucagon stimulates the liver to convert glycogen to glucose and release it into the bloodstream. Signup and view all the answers

What type of gland secretes insulin and glucagon?

Endocrine Signup and view all the answers

Where is PTH released from?

parathyroid gland Signup and view all the answers

What does PTH do?

Increases calcium levels in the blood by facilitating absorption and reabsorption. Signup and view all the answers

Where is calcitonin secreted from?

the parafollicular cells of the thyroid gland Signup and view all the answers

What does calcitonin do?

Lowers blood calcium levels by moving calcium from the blood into bones. Signup and view all the answers

What are PTH and calcitonin in terms of feedback loops?

negative feedback loop which raises levels when needed and lowers when needed Signup and view all the answers

Study Notes

Insulin and Glucagon Overview

Insulin and glucagon are secreted by the pancreas to regulate blood glucose levels.
Insulin lowers blood glucose; secreted when glucose levels are high.
Glucagon raises blood glucose; secreted when glucose levels are low.

Insulin Function

Produced by beta cells found in clusters called Islets of Langerhans.
Water-soluble, binds to receptors on muscle and liver cell membranes, not able to pass through.
Stimulates cells to absorb glucose, which is converted to glycogen in liver and muscle, or stored as fat in adipose tissue.

Glucagon Function

Secreted by alpha cells in the pancreas, also water-soluble.
Stimulates liver to convert stored glycogen back to glucose when blood glucose is low, increasing glucose in the bloodstream.

Hormonal Interaction

Antagonistic hormones have opposing effects on the body.
Insulin and glucagon operate via negative feedback loops: insulin secretion stops as blood glucose normalizes, glucagon secretion halts once levels return to normal.

Calcium Regulation

Parathyroid hormone (PTH) is released from the parathyroid gland; increases blood calcium levels.
PTH enhances calcium absorption in the intestines, reabsorption in kidneys, and releases calcium from bones by stimulating osteoclasts.

Calcitonin Role

Secreted by parafollicular cells of the thyroid gland; lowers blood calcium levels.
Promotes bone formation by inhibiting osteoclast activity, redistributing calcium from blood to bones.
Reduces calcium reabsorption in kidneys, aiding in lowering blood calcium.

Feedback Loops in Calcium Regulation

Both PTH and calcitonin are part of a negative feedback loop, adjusting calcium levels appropriately in response to physiological needs.

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Description

Test your knowledge of insulin and glucagon with these flashcards. Learn about their functions, secretion points, and their roles in managing blood glucose levels. Perfect for students studying biology or health sciences.