Blood Glucose Regulation

This lesson explains how the body regulates blood glucose concentration using hormones produced by the pancreas. Understanding negative feedback in the context of blood glucose is a core part of the AQA GCSE Biology specification. This lesson also covers Type 1 and Type 2 diabetes.

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Why Must Blood Glucose Be Controlled?

Blood glucose concentration must be kept within a narrow range to ensure cells have a constant supply of glucose for cellular respiration, but not so much that it causes damage.

Condition	What Happens
Blood glucose too high	Water moves out of cells by osmosis, causing dehydration of cells; excess glucose can damage blood vessels and organs
Blood glucose too low	Cells do not have enough glucose for respiration; this can lead to unconsciousness or death
Normal range	Sufficient glucose is available for cellular respiration; cells function optimally

Sources of blood glucose:

• Eating carbohydrate-containing foods (digested to glucose and absorbed into the blood)
• Glycogen breakdown in the liver (glycogen is converted back to glucose)