Why is the pancreas described as both an exocrine and an endocrine gland?

Its acinar tissue secretes digestive enzymes into a duct leading to the duodenum, which is exocrine secretion, while its Islets of Langerhans secrete hormones directly into the blood, which is endocrine secretion.

What is the exocrine tissue of the pancreas called, and what does it secrete?

It is called acinar tissue, and it secretes pancreatic juice containing digestive enzymes such as amylase, proteases and lipase.

How can the Islets of Langerhans be recognised in a stained photomicrograph of pancreas?

They appear as roughly spherical, pale-stained clusters of cells scattered among the much darker-stained acinar tissue.

OCR A-Level Biology B H422

The Developing Cell: Cell Division and Cell Differentiation

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The Principles and Importance of Homeostasis

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The Hormonal Control of Blood Glucose and the Management of Diabetes

Topic overview The pancreas as an endocrine gland The regulation of blood glucose by negative feedback Types of diabetes and diagnostic testing Treating and managing diabetes

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The Hormonal Control of Blood Glucose and the Management of Diabetes

4 subtopics
12 things to know
Components 01, 02 and 03

What The Hormonal Control of Blood Glucose and the Management of Diabetes covers

The Hormonal Control of Blood Glucose and the Management of Diabetes is examined in all three written papers — the specification states that Components 01, 02 and 03 can each assess content from any of the five modules, so nothing is confined to one paper. It covers the pancreas as an endocrine gland, the regulation of blood glucose by negative feedback, types of diabetes and diagnostic testing and treating and managing diabetes.

Where it is assessed

Components 01, 02 and 03

Every module can be assessed on any of the three papers.

Check the OCR specification ↗

The 4 subtopics

Each one has its own page.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Evaluation

Give one advantage and one disadvantage of using an electron micrograph rather than a photomicrograph to study pancreatic tissue.

Key term

How does a rise in blood glucose concentration cause a β cell to secrete insulin?

Key term

Why is the control of insulin secretion described as negative feedback?

Key term

How does a glucose biosensor measure the glucose concentration of a blood sample?

Key term

Why is a podiatrist part of the diabetes care team?

Key term

Name the two hormones secreted by the Islets of Langerhans and the cells that produce each.

Key term

What causes Type 1 diabetes?

Key term

Why must insulin be injected rather than swallowed?

Key term

Why does the acinar tissue of the pancreas take up stain more heavily than an islet does?

Key term

Which cells of the pancreas detect a rise in blood glucose concentration?

Key term

What is meant by insulin resistance in Type 2 diabetes?

Key term

What is meant by a basal-bolus insulin regime?

Take The Hormonal Control of Blood Glucose and the Management of Diabetes further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

Insulin vs Glucagon
Insulin: the secretion of the β cells of the Islets of Langerhans, which lowers blood sugar by promoting its uptake and storage. Glucagon: the secretion of the α cells of the Islets of Langerhans, which raises blood sugar by mobilising the store held in the liver.
Glycogen vs Glucagon
Glycogen: the branched storage polysaccharide held in liver and muscle cells as a reserve of respiratory substrate. Glucagon: a peptide hormone released when blood sugar falls too low, which acts on the liver to release sugar into the blood.
Type 1 diabetes vs Type 2 diabetes
Type 1 diabetes: an autoimmune condition in which the β cells are destroyed so none of the lowering hormone is made at all, and injections are needed from the start. Type 2 diabetes: a condition in which the cells respond poorly to a hormone that is still being secreted, usually developing later in life and linked to obesity.

Questions from this topic

Each one with the model answer underneath.

1
Why is the pancreas described as both an exocrine and an endocrine gland?
Model answer
Its acinar tissue secretes digestive enzymes into a duct leading to the duodenum, which is exocrine secretion, while its Islets of Langerhans secrete hormones directly into the blood, which is endocrine secretion.
2
Name the two hormones secreted by the Islets of Langerhans and the cells that produce each.
Model answer
Insulin, produced by the β cells, and glucagon, produced by the α cells.
3
What is the exocrine tissue of the pancreas called, and what does it secrete?
Model answer
It is called acinar tissue, and it secretes pancreatic juice containing digestive enzymes such as amylase, proteases and lipase.
4
How can the Islets of Langerhans be recognised in a stained photomicrograph of pancreas?
Model answer
They appear as roughly spherical, pale-stained clusters of cells scattered among the much darker-stained acinar tissue.
5
Why does the acinar tissue of the pancreas take up stain more heavily than an islet does?
Model answer
Acinar cells are packed with rough endoplasmic reticulum and with granules of digestive enzyme, and these structures bind a great deal of stain.
6
Approximately what proportion of the mass of the pancreas is made up of the Islets of Langerhans?
Model answer
Only about 1 to 2 per cent.

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The Developing Cell: Cell Division and Cell Differentiation

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measles and .

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