(todo 7.4-8) Hormones and Fertility - Paper 2

Question 1

Define hormone

Answer 1

A hormone is a chemical substance, produced by a gland and carried in the bloodstream, which alters the activity of specific target organs.

Question 2

Recall the names and locations of relevant endocrine glands.

Answer 2

• Pituitary gland
• Thyroid gland
• Pancreas
• Adrenal glands
• Ovaries
• Testes

Question 3

Where is adrenalin produced?

Answer 3

In the adrenal glands.

Question 4

Explain how adrenalin prepares the body for fight or flight.

Answer 4

It increases breathing rate, heart rate, blood pressure, flow of blood to muscles, conversion of glycogen to glucose, etc.

Question 5

Explain how thyroxine controls metabolic rate as an example of negative feedback.

Answer 5

Low thyroxine levels in the bloodstream stimulate the hypothalamus to release TRH which stimulates the pituitary gland to release TSH so the thyroid releases more thyroxine. So blood levels return to normal.
Normal thyroxine levels in the bloodstream inhibit TRH release from the hypothalamus and TSH production in the pituitary gland, so normal levels are maintained.