Homeostasis and hormones flashcards

Homeostasis is the process by which the body maintains a stable internal environment despite changes in external conditions. It involves monitoring and adjusting variables such as body temperature, blood glucose concentration, and water content. The nervous system and the endocrine system both play roles in homeostasis, but hormones are particularly important for slower, longer-lasting responses. Key hormones include insulin and glucagon, which are produced in the pancreas and work together to regulate blood glucose levels. Insulin lowers blood glucose by stimulating cells to take in glucose and the liver to convert it to glycogen. Glucagon raises blood glucose by stimulating the liver to break down glycogen back into glucose. Understanding how these systems fail, as in type 1 and type 2 diabetes, is also essential.

1. Card 1

   What is homeostasis?

   Homeostasis is the maintenance of a stable internal environment within the body, keeping conditions such as temperature and blood glucose within narrow limits.

2. Card 2

   What is the endocrine system?

   The endocrine system is a collection of glands that produce and release hormones directly into the blood to regulate body processes.

3. Card 3

   How do hormones travel around the body?

   Hormones are chemical messengers released by glands into the bloodstream, which carries them to target organs where they cause a response.

4. Card 4

   Which organ monitors and controls blood glucose concentration?

   The pancreas monitors blood glucose levels and releases the hormones insulin and glucagon to bring levels back to normal.

5. Card 5

   What does insulin do and when is it released?

   Insulin is released when blood glucose is too high. It causes body cells to absorb glucose and the liver to convert glucose into glycogen for storage.

6. Card 6

   What does glucagon do and when is it released?

   Glucagon is released when blood glucose is too low. It stimulates the liver to break down glycogen back into glucose, raising blood glucose levels.

7. Card 7

   What is the difference between type 1 and type 2 diabetes?

   In type 1 diabetes the pancreas cannot produce insulin. In type 2 diabetes the body's cells no longer respond properly to insulin.

8. Card 8

   How is type 1 diabetes treated?

   Type 1 diabetes is treated by injecting insulin regularly, as the pancreas cannot produce it. Diet and exercise are also managed carefully.

9. Card 9

   What is a negative feedback mechanism?

   Negative feedback is when a change from the normal level triggers a response that reverses that change, returning conditions back to the set point.

10. Card 10

    Name two differences between nervous and hormonal communication.

    The nervous system acts quickly via electrical impulses with short-lived effects. The hormonal system acts more slowly via the blood but produces longer-lasting responses.

11. Card 11

    What is glycogen and where is it stored?

    Glycogen is a storage carbohydrate made from many glucose molecules joined together. It is stored mainly in the liver and muscle cells.

12. Card 12

    Why must body temperature be kept close to 37 degrees Celsius?

    Enzymes in the body work best at around 37 degrees Celsius. If temperature strays too far, enzyme activity is reduced or the enzyme becomes denatured.

• Many students confuse insulin and glucagon, incorrectly stating that glucagon lowers blood glucose rather than raises it.
• Students often say that type 1 and type 2 diabetes are the same condition, when in fact type 1 involves no insulin production whereas type 2 involves a loss of sensitivity to insulin.
• A common error is to describe hormones as travelling through nerves rather than through the bloodstream, mixing up the nervous and endocrine systems.

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