The shape of the lesson
By the end of the lesson, learners can
- Glands, hormones and targets: Choose male or female, then click each gland.
- Adrenaline: fight or flight: Press A sudden fright and watch the readings change, then press Calm down.
- Nerves versus hormones: Press Send both: a nerve impulse and a hormone set off at the same moment.
- Hormone: chemical, made by a gland, carried by the blood, alters specific target organs.
- Pairs: adrenal glands and adrenaline, pancreas and insulin (and glucagon), testes and testosterone, ovaries and oestrogen.
- Adrenaline: breathing rate up, heart rate up, pupils wider; (Extended) blood glucose up.
- Nerves vs hormones: faster and shorter versus slower and longer-lasting.
One picture every idea returns to
A hormone is a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs. The adrenal glands secrete adrenaline, the pancreas insulin, the testes testosterone and the ovaries oestrogen. Adrenaline is secreted in fight or flight situations and increases breathing rate, heart rate and pupil diameter. Nervous control is faster but shorter-lasting than hormonal control.
Forty-five minutes, phase by phase
| Time | Phase | What happens in the room | Grouping |
|---|---|---|---|
| 0 to 5 min | Hook: predict | Open with the question in the title, Chemical messages in the blood.. Not every message travels along a nerve. Put the figure on the board: it is the one picture every idea in the lesson returns to. | Whole class, then pairs |
| 5 to 13 min | Teach and check: Glands, hormones and targets | Choose male or female, then click each gland. Project tab 1 of the lab (Endocrine glands and their hormones) and let a student drive it while the class predicts. | Whole class, then pairs |
| 13 to 21 min | Teach and check: Adrenaline: fight or flight | Press A sudden fright and watch the readings change, then press Calm down. Project tab 2 of the lab (Adrenaline and fight or flight) and let a student drive it while the class predicts. | Pairs |
| 21 to 30 min | Teach and check: Nerves versus hormones | Press Send both: a nerve impulse and a hormone set off at the same moment. Project tab 3 of the lab (Nervous and hormonal control compared) and let a student drive it while the class predicts. | Think-Pair-Share |
| 30 to 36 min | Check | The four Stage 1 questions from the student lesson, answered on mini whiteboards or by show of fingers. Re-teach the one most get wrong. | Individual, then whole class |
| 36 to 43 min | Plenary | The exam-style questions from Stage 2, one at a time: thirty seconds alone, then a random call. The feedback lines in the key give the examiner's wording. | Individual, random call |
| 43 to 45 min | Exit and homework | Set the worksheet below (6 questions, 22 marks). Learners self-assess against the objectives before they leave. | Individual |
Protect the parts that carry the learning
The sequence carries about fifty minutes of material, so the lab is driven by one student while the class predicts rather than explored freely. Times are a guide.
Protected: the check at 30 minutes. It is the only individual read on whether the key idea landed, and it is not cut.
Cut first if the build overruns: the last check in Nerves versus hormones, never the check or the plenary.
In a 60 minute block: run worksheet questions 1 to 3 in class as a Rally Coach set and model both the hardest worked example and its check live.
Think-Pair-Share
Pose the question, give thirty seconds of silent thinking, then a minute to compare with a partner before a few pairs share with the class. The silent minute is the part that cannot be cut.
The full structure, with its variations and the other twelve, is on the cooperative-learning page.
What to head off, and how
| Trap learners fall into | Teaching move that pre-empts it |
|---|---|
| A hormone is carried in the blood plasma, not by red blood cells, and it is made by a gland, not by the target organ. | Do not confuse the adrenal glands with the kidneys they sit on. |
| Adrenaline increases pupil diameter. | Do not mix this up with the pupil reflex, where bright light makes the pupil smaller. |
| The syllabus comparison is about speed of action and duration of effect. | Write both halves: nerves are faster and their effect is shorter; hormones are slower and their effect lasts longer. |
Hormones: worksheet
6 questions, 22 marks. Written in the style of the papers; no past paper question is reproduced.
Define the term hormone.
Name the hormone secreted by each of these glands: adrenal glands, pancreas, testes, ovaries.
A cyclist sees a car pull out in front of her. Describe three effects of the adrenaline secreted and explain how they help her react.
A student's heart rate was measured before and during a frightening film scene.
| Time / min | 0 | 1 | 2 | 3 | 6 | 10 |
|---|---|---|---|---|---|---|
| Heart rate / beats per min | 72 | 72 | 118 | 110 | 90 | 76 |
The scene began at 1 min and ended at 2 min. (a) Calculate the percentage increase in heart rate between 1 min and 2 min. (b) Use the data to explain why this response is thought to be hormonal, not only nervous.
Compare nervous control and hormonal control in terms of speed of action and duration of effect, and explain the difference in speed.
Extended. Describe the role of adrenaline in the control of metabolic activity.
Answer key and marking notes
- A chemical substance produced by a gland.
- Carried by the blood.
- Which alters the activity of one or more specific target organs.
- Adrenal glands: adrenaline.
- Pancreas: insulin (Extended: also glucagon).
- Testes: testosterone.
- Ovaries: oestrogen.
- Adrenaline is secreted by the adrenal glands in a fight or flight situation.
- Heart rate increases, so blood carries oxygen and glucose to the muscles faster.
- Breathing rate increases, taking in more oxygen for respiration in the muscles.
- Pupil diameter increases, letting more light into the eyes.
- (a) (118 − 72) ÷ 72 × 100 = 64% (63.9%).
- (b) Heart rate stayed high for several minutes after the scene ended.
- It took about 8 minutes to return close to the starting value.
- A long-lasting effect is typical of a hormone (adrenaline) carried in the blood; a purely nervous response would fade quickly.
- Nervous control acts faster than hormonal control.
- The effect of nervous control is shorter-lived; the effect of hormonal control lasts longer.
- Impulses travel as electrical signals along neurones, which is very fast.
- Hormones must be carried in the blood to the target organ, which takes longer.
- Adrenaline increases the blood glucose concentration (the liver releases glucose into the blood).
- It increases the heart rate, so glucose and oxygen are delivered to the muscles faster.
- More respiration can take place in the muscles, releasing more energy for action.
8 multiple-choice questions on this lesson
From the topic question bank. Assign them in the app for a marked score in your gradebook, or run the topic as a class game.
The diagram shows some endocrine glands. Which row names the hormone secreted by P, Q and R?
- AP insulin, Q adrenaline, R testosterone
- BP adrenaline, Q insulin, R testosterone
- CP insulin, Q testosterone, R adrenaline
- DP oestrogen, Q adrenaline, R insulin
How are hormones carried from a gland to their target organs?
- ADissolved in the blood
- BAlong sensory neurones
- CThrough the lymph nodes only
- DBy diffusion through the body cavity
Adrenaline reaches every organ in the body, but only some organs respond to it. Why?
- AOnly its target organs respond to it
- BIt is broken down before it reaches other organs
- COther organs are protected by a layer of fat
- DIt only travels in arteries to the heart
Which combination of effects is caused by adrenaline?
- AFaster breathing, faster heart rate, wider pupils
- BSlower breathing, faster heart rate, narrower pupils
- CFaster breathing, slower heart rate, wider pupils
- DSlower breathing, slower heart rate, narrower pupils
A person touches a hot pan and pulls their hand away in 0.1 s. Later their heart is still racing 10 minutes after the fright. Which explanation is correct?
- AThe hand movement was nervous control; the racing heart was hormonal control
- BThe hand movement was hormonal control; the racing heart was nervous control
- CBoth responses were nervous, because both followed a stimulus
- DBoth responses were hormonal, because adrenaline was released
Extended: which hormone is secreted by the pancreas, as well as insulin?
- AGlucagon
- BGlycogen
- CAdrenaline
- DOestrogen
Extended: how does adrenaline help muscles to release more energy during fight or flight?
- AIt raises blood glucose and heart rate, so muscles receive more glucose and oxygen
- BIt lowers blood glucose so the muscles are forced to respire faster
- CIt slows the heart so blood has more time to give up oxygen
- DIt acts as a fuel that muscles respire directly
Extended: an athlete's blood glucose rises from 5.0 to 6.5 mmol/dm3 just before a race, without eating. What is the percentage increase, and the most likely cause?
- A30%, adrenaline causing the liver to release glucose
- B30%, insulin causing the liver to release glucose
- C23%, adrenaline causing the liver to release glucose
- D1.5%, glucagon from the adrenal glands
Quiz key
P is the pancreas, which secretes insulin. Q is an adrenal gland on top of the kidney, which secretes adrenaline. R is a testis, which secretes testosterone. Swapping adrenaline and insulin confuses the pancreas with the adrenal glands; oestrogen comes from the ovaries, which are not present in a male body.
Endocrine glands secrete hormones directly into the blood, which carries them all round the body. Neurones carry electrical impulses, not hormones. Lymph nodes filter lymph and are not the transport route for hormones. Diffusion alone would be far too slow to reach distant organs.
A hormone alters the activity of specific target organs; other organs are exposed to it but do not respond. It is not destroyed before reaching them, since the blood takes it everywhere. Fat does not shield organs from blood-borne chemicals. Adrenaline travels in the blood to the whole body, not just to the heart.
Adrenaline increases breathing rate, increases heart rate and increases pupil diameter, preparing the body for action. Every other option includes at least one effect in the wrong direction: a slower heart or breathing rate would supply less oxygen, and narrower pupils is the bright-light pupil reflex, not an effect of adrenaline.
The very fast, short response of the hand is typical of nervous control (a reflex). The long-lasting effect on the heart is typical of a hormone, adrenaline, which stays in the blood. Reversing them ignores that nerves are faster and shorter-lasting. Hormonal responses also follow stimuli, so having a stimulus does not make a response nervous, and a reflex in 0.1 s is far too fast for a hormone.
The pancreas secretes both insulin and glucagon. Glycogen is the carbohydrate stored in the liver and muscles, not a hormone. Adrenaline comes from the adrenal glands, and oestrogen from the ovaries.
Adrenaline increases blood glucose concentration and increases heart rate, so glucose and oxygen are delivered to the muscles faster for respiration. It raises rather than lowers blood glucose. It speeds up the heart, not slows it. Adrenaline is a signalling chemical, not a respiratory substrate.
The change is 6.5 − 5.0 = 1.5 mmol/dm3, and 1.5 ÷ 5.0 × 100 = 30%. Nervousness before a race causes adrenaline secretion, which raises blood glucose. Insulin lowers blood glucose rather than raising it. 23% comes from dividing by the final value. 1.5 is the absolute change, not a percentage, and glucagon comes from the pancreas, not the adrenal glands.
What to project
The student lesson embeds these tabs. Open them full screen on the projector; every slider has a drag handle on the stage.
Slides for this lesson
A projectable deck for every pack is on the way. Until then, present the student lesson full screen: its sections, figure and lab tabs follow the same order as the plan above.