B9.3 : Hormones

Question 1

Hormones

Answer 1

1. Changes the activity of one or more specific target organs
2. Carried by the blood
3. A Chemical substance
4. Produced by glands
5. Hormones travel to target organs where they initiate a response.

Question 2

Endocrine Glands

Answer 2

1. The endocrine system coordinates the body’s response to changes in the environment using chemical messengers (hormones).
2. Endocrine glands are groups of cells that produce hormones and secrete them into the bloodstream, where they travel to target organs.

Question 3

Types of endocrine glands

Answer 3

1. Pancreas
2. Adrenal Glands
3. Testes (for males)
4. Ovaries (for females)
5. Pituitary
6. Thyroid

Question 4

Pancreas (endocrine glands)

Answer 4

1. The pancreas produces insulin and glucagon, both of which are involved in regulating blood glucose levels.
2. Insulin acts to decrease blood glucose levels.
3. Glucagon acts to increase blood glucose levels.

Question 5

Adrenal Glands (endocrine)

Answer 5

1. They produce adrenaline, which triggers the ‘fight or flight’ response when an organism is presented with a dangerous situation.
2. Adrenaline increases breathing and pulse rate to provide nutrients to respiring cells more quickly.
3. Adrenaline widens pupils to take in more visual information.

Question 6

Testes (endocrine glands)

Answer 6

The testes produce testosterone, which controls puberty and sperm production.

Question 7

Ovaries (endocrine glands)

Answer 7

The ovaries produce oestrogen, which controls puberty and is one of the main hormones in the regulation of the menstrual cycle.

Question 8

Pituitary (endocrine glands)

Answer 8

1. This is the main endocrine gland and it is found in the brain.
2. It is linked to the hypothalamus, which is a region of the brain that receives signals from the receptors.
3. Often known as the master gland because many hormones released by the pituitary gland cause other glands to release hormones

Question 9

Thyroid (endocrine glands)

Answer 9

1. This gland is in our neck

2. It releases thyroxine, which regulates our metabolism, heart rate and temperature.

Question 10

Difference between endocrine system and central nervous system

Answer 10

1. Endocrine (hormonal) system triggers a slower response while the CNS triggers a rapid response
2. Endocrine (hormonal) system uses chemical messengers that are carried by blood which the CNS uses electrical signals that are carried by neurones.
   3 . Endocrine (hormonal) system response can be long-lasting which CNS response is very short
3. Endocrine (hormonal) system can act on large areas of the body while the CNS acts on a very precise part of the body