4.5.3 Hormonal coordination in humans (will come up) P2 Flashcards
What is the endocrine system
The body’s coordination system which involves hormones
What is a hormone
A hormone is a chemical messenger secreted by a gland
It travels in the blood to a target organ, where it causes a response
What type of organ secretes hormones
Glands
Which gland controls many other glands in the body
The pituitary gland
Why is the pituitary gland considered a ‘master gland’
It secretes a wide range of hormones, some of which may stimulate other endocrine glands
What is the role of the pituitary gland in the endocrine system
Secretes human growth hormone - controls human growth
Stimulates the thyroid gland
Stimulates ovulation and the production of oestrogen in the ovaries
Stimulates the production of sperm and testosterone in the testes
What is the role of the thyroid gland in the endocrine system
Secretes the hormones thyroxine - controls metabolism, heart rate and body temperature
What is the role of the pancreas in the endocrine system
Secretes the hormone insulin - controls blood glucose levels
What is the role of the adrenal gland in the endocrine system
Secretes adrenaline - controls the body’s ‘fight or flight’ response
What is the role of the ovaries in the endocrine system
Secrete oestrogen, which coordinates the menstrual cycle and the development of female secondary sexual characteristics
What is the role of the testes in the endocrine system
Secrete testosterone, which coordinates the production of sperm and the development of male secondary sexual characteristics
Which organ monitors and controls blood glucose concentration
The pancreas
How does the pancreas respond when blood glucose levels are too high
The pancreas secretes the hormone insulin
Insulin binds to receptors on the liver and muscles, causing excess glucose to be converted into glycogen and stored
How does the pancreas respond when blood glucose levels are too low
The pancreas secretes the hormone glucagon
Glucagon binds to liver cells, causing glycogen to be converted into glucose and released into the blood
How is blood glucose concentration controlled using a negative feedback loop
When the blood glucose concentration rises or falls below the optimum, a hormone is secreted by the pancreas
The action of either hormone (insulin or glucagon) helps bring back the concentration to the correct level
What is Type 1 diabetes
An autoimmune disorder in which the pancreas does not produce sufficient insulin to control the blood glucose concentration
As a result, blood glucose levels are often very high, leading to excessive urination, tiredness and weight loss
How can Type 1 diabetes be treated
Insulin injections before meals - allows glucose to be converted into glycogen
Limiting carbohydrate intake
Attempts using pancreas and pancreatic cell transplants; investigations into genetic engineering of pancreatic cells
What is Type 2 diabetes
A disorder in which the body’s cells stop responding to insulin, leading to an uncontrolled blood glucose concentration
Its onset is linked with increasing age and obesity
How can type 2 diabetes be treated
Following a carefully-controlled diet
Doing regular exercise
Losing weight
Use of drugs which increase insulin production and effectiveness
