4.4 - Regulation of Blood Glucose Levels

Explain glucose’s role in the body

• glucose is the main source of energy for the body

• glucose is used in cellular respiration to create ATP (usable energy) for cells, functions and the body

Why must Glucose levels maintain constant?

• concentration of blood glucose levels is 3.0 - 7.7 mmol/L

• must remain relatively constant for effective functioning of cells and, therefore, individual

How is glucose obtained?

Glucose is obtained from diet:

• foods with carbohydrates

  • get broken down into glucose (simple sugars) in digestion

What is glucose converted into?

glucose gets converted into glycogen in the liver when there is an excess amount OR fat stores in the muscle

What gland is responsible for the regulation of glucose?

Pacreas:

• Islets of Langerhans: clusters of alpha and beta cells

  • Alpha cells: detect low levels of blood glucose, they produce & secrete glucagon hormone to raise levels

    • liver will convert glycogen back to glucose, muscle cells convert fat back to glucose

  • Beta cells: detect high blood glucose levels, secrete insuline to lower them

    • liver converts excess glucose into glycogen, muscle cells stores glucose as fat

What is Type 1 diabetes

• autoimmune diseases, genetic disorder

• the body cannot produce insulin

• glucose cannot enter the cells to be used in cellular respiration to create ATP, glucose levels remain high

Type 2 diabetes

• caused by diet, lifestyle

• cells do not respond to insulin, so, overtime, insulin is not produced

put in symptoms

Symptoms of diabetes and why?

1. More Urine (Polyuria)

• Why: When blood glucose levels are too high (hyperglycemia), the kidneys try to filter out the excess glucose.

• Result: Glucose spills into the urine (normally it shouldn’t), and it pulls water with it (osmosis), leading to increased urine production.

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2. Feeling Thirsty More (Polydipsia)

• Why: You're urinating more, so your body is losing a lot of water.

• Result: To compensate for this dehydration, your brain signals thirst, making you want to drink more.

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3. Glucose in Urine (Glycosuria)

• Why: The kidneys usually reabsorb all glucose from the blood, but when glucose levels are too high (usually above ~180 mg/dL), they can’t keep up.

• Result: Glucose "leaks" into the urine because the reabsorption threshold is exceeded.

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4. Being More Hungry (Polyphagia)

• Why: Even though there’s lots of glucose in the blood, it’s not getting into cells (due to lack of insulin or insulin resistance).

• Result: Your cells are "starving," so your body signals you to eat more to get energy into the cells—though it doesn’t help unless insulin is working properly.

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5. Slow Healing Wounds

• Why: High blood glucose damages blood vessels and impairs circulation, reducing oxygen and nutrient delivery to wounds.

• Also: High glucose weakens immune cells and increases inflammation.

• Result: Wounds take longer to heal and are more prone to infection.