New
New
Year 10
Edexcel
Higher

Adrenaline, thyroxine and negative feedback, including TRH

I can describe the roles of the hormones adrenaline and thyroxine in the human body, and explain what is meant by negative feedback.

New
New
Year 10
Edexcel
Higher

Adrenaline, thyroxine and negative feedback, including TRH

I can describe the roles of the hormones adrenaline and thyroxine in the human body, and explain what is meant by negative feedback.

Lesson details

Key learning points

  1. The hormone adrenaline is secreted by the adrenal gland during stress; it causes the body to prepare for rapid action.
  2. The hormone thyroxine is secreted by the thyroid gland; it controls growth and the rates of chemical reactions in cells.
  3. The pituitary gland secretes hormones that control other glands.
  4. Hypothalamus secretes TRH; this causes pituitary gland to secrete TSH; this causes thyroid gland to secrete thyroxine.
  5. Thyroxine causes the pituitary gland to stop secreting TSH; this is an example of negative feedback.

Common misconception

Negative feedback only works to reverse high levels back to normal.

The slide deck has several slides where changes are described as being high and low and there is a CFU question in the final learning cycle that specifically assesses this misconception.

Keywords

  • Adrenaline - A hormone secreted by the adrenal glands in times of fear or stress.

  • Thyroxine - A hormone secreted by the thyroid gland that stimulates the basal metabolic rate.

  • Negative feedback - A mechanism where changes to conditions cause an action to reverse the change, keeping conditions stable.

  • Gland - An organ or tissues that produces and secretes substances, such as hormones.

You can link negative feedback to previous lessons such as regulating blood glucose to reinforce the idea of negative feedback with a different example.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
The image shows glands of the endocrine system. What are the circled glands called?
An image in a quiz
thyroid glands
pancreas
Correct answer: adrenal glands
ovaries
Q2.
Which hormone is secreted by the adrenal glands?
thyroxine
oestrogen
adrenal stimulating hormone (ASH)
Correct answer: adrenaline
Q3.
Which gland in the human body is involved in regulating metabolism?
pancreas
Correct answer: thyroid gland
testes
adrenal gland
Q4.
What is the name of the hormone secreted by the thyroid gland?
insulin
Correct answer: thyroxine
testosterone
thyroid stimulating hormone (TSH)
Q5.
Which gland is known as the master gland?
Correct answer: pituitary gland
hypothalamus
pancreas
ovaries
thyroid gland
Q6.
Regulation of constant internal conditions for optimum enzyme activity and cell function is called ...
Correct Answer: homeostasis

6 Questions

Q1.
Match the hormone to the gland that it is secreted by.
Correct Answer:adrenaline,adrenal gland

adrenal gland

Correct Answer:TSH,pituitary gland

pituitary gland

Correct Answer:thyroxine,thyroid gland

thyroid gland

Correct Answer:TRH,hypothalamus

hypothalamus

Q2.
Which of the following correctly describe the effect of adrenaline on the body?
Decreased breathing and heart rate.
Correct answer: Stored glycogen is converted to glucose.
Correct answer: Blood is diverted to major limb muscles.
Pupils dilate to become smaller in size.
Q3.
What is the mechanism called where the body detects changes in conditions, then reverses these changes to bring levels back to normal?
Correct Answer: negative feedback
Q4.
Put these steps in order to show the body's response to low levels of thyroxine.
1 - Low thyroxine levels are detected.
2 - The hypothalamus is stimulated to secrete TRH.
3 - The pituitary gland secretes TSH.
4 - The thyroid gland is stimulated to produce thyroxine.
5 - Thyroxine levels increase back to normal.
Q5.
Which of the following statements are true when thyroxine levels are too high?
The hypothalamus secretes more TRH.
Correct answer: The hypothalamus inhibits TRH.
There is more TSH available to stimulate the thyroid gland.
Correct answer: TSH in inhibited and so does not stimulate the thyroid gland.
Q6.
The graph below shows changes in thyroxine over time. Which statements about the graph are correct?
An image in a quiz
At point B TRH and TSH are being secreted.
Correct answer: At point D TRH and TSH are being secreted.
Correct answer: At point B TSH is being inhibited.
At point D TSH is being inhibited.