Biology - 11 Hormonal Coordination - 11.1 Principles of Hormonal Control & 11.2 The Control of Blood Glucose Levels & 11.3 Treating Diabetes

Endocrine system

hormone system that regulates processes such as growth, reproduction, and metabolism

Hormone

chemical messengers that are produced in one tissue and affect another

How are hormones detected?

target organ has receptors on the cell membranes

Rapid-response hormones [2]:

- insulin
- adrenaline

What gland controls most hormone action?

pituitary gland

What hormones does the pituitary gland release? [3]

- ADH
- FSH
- TSH

Roles of the pituitary gland [4]:

- control growth in children
- stimulates the thyroid to regulate metabolism
- (in women) stimulates ovaries to produce and release eggs and oestrogen
- (in men) stimulates the testes to produce eggs and testosterone

Role of the thyroid gland:

controls the metabolic rate of the body

Role of the pancreas:

controls blood glucose levels

Role of the adrenal gland:

prepare body for stressful situations

Roles of the ovaries [2]:

- controls development of female secondary sex characteristics
- regulates the menstrual cycle

Roles of the testes [2]:

- controls development of the male secondary sex characteristics
- regulates sperm production

What does insulin do? [3]

- allows glucose to pass into the body's cells for respiration
- causes the liver to convert glucose into glycogen
- regulates the storage of glycogen in muscles and liver

When is insulin produced?

when blood sugar is high

Glycogen

insoluble form of glucose, used for storage

What happens to excess glucose?

it is converted into lipids and stored

What does glucagon do?

raises blood sugar levels by making the liver break down glycogen

Negative feedback

a mechanism of homeostasis, where a change in a variable that is being monitored triggers a response that counteracts the change

What causes type 1 diabetes?

when the pancreas does not make enough/any insulin

Effects of untreated type 1 diabetes [5]:

- blood glucose concentration is very high after eating
- kidneys excrete glucose in the urine
- a lot of urine is produced leading to dehydration
- glucose cannot be used for respiration leading to lack of energy
- fat and protein are used instead, so weight is lost

What causes type 2 diabetes?

body cells stop responding to insulin

What causes type 2 diabetes to develop? [4]

- obesity
- lack of exercise
- age
- genetic tendency

How is type 1 diabetes treated?

insulin injections before meals

How could type 1 diabetes be cured? [3]

- pancreatic transplant
- pancreatic cell transplant
- stem cells

What are the issues with a pancreatic transplant? [3]

- not enough donors
- risky operation
- patient must take immunosuppressants

How could stem cells be used to treat type 1 diabetes?

therapeutic cloning and use of the embryonic stem cells to produce insulin-producing cells with no rejection

How is type 2 diabetes treated without medical intervention? [3]

- eating a balanced diet and regulating carbohydrates
- losing weight
- regular exercise

How is type 2 diabetes treated with medical intervention? [4]

- drugs that increase cells' sensitivity to insulin
- drugs that help pancreas produce more insulin
- drugs that reduce the amount of glucose absorbed from the gut
- insulin injections