--- title: "Nerve or hormone?" subtitle: "Year 9 Biology · Coordination and control · Lesson 4" --- # Nerve or hormone? **Name:** {{field-24}} **Date:** {{field-15}} **Class:** {{field-15}} > **Key question:** A fright makes you jump in a fraction of a second. Your heart is still pounding a few minutes later. Two different systems are at work. :::teacher-note **In one sentence:** Students compare the nervous and endocrine systems by message, route, speed, duration and target (AC9S9U01, node 4, a hinge node). **Students should be able to say:** I can explain that hormones travel in the blood, not along nerves. I can compare nervous and hormonal responses by speed and duration. I can explain why only target cells respond to a hormone. **Width:** the unmarked parts are the floor every student does (Engage, Explore, Explain, Evaluate). Typical and Wider sections add contexts, not difficulty. Students work in the online tutorial alongside this sheet. ::: ## Engage :::keep-together **Adrenaline is a hormone released when you get a fright. How does it reach your heart?** ☐ It is made in the heart ☐ In the blood, carried all round the body ☐ Through the air you breathe ☐ Along a nerve, like an impulse My prediction, and why: {{lines-3}} ::: :::teacher-note **What happens:** In the blood. The adrenal glands release it into the bloodstream, which carries it everywhere; cells with the right receptors (heart, liver, muscles) respond. ::: ## Explore Try it on the board in the tutorial. Was your prediction right? What was different? {{lines-2}} ## Explain: comparing the two :::keep-together ### Which system **Nervous system or endocrine system?** Groups: Nervous system, Endocrine system - Electrical impulses: {{field-15}} - Chemical messages in the blood: {{field-15}} - Very fast: {{field-15}} - Effects last minutes to years: {{field-15}} - Goes to one exact place: {{field-15}} - Reaches the whole body; target cells respond: {{field-15}} ::: :::teacher-note **Answer:** Electrical impulses → Nervous system; Chemical messages in the blood → Endocrine system; Very fast → Nervous system; Effects last minutes to years → Endocrine system; Goes to one exact place → Nervous system; Reaches the whole body; target cells respond → Endocrine system ::: :::keep-together ### Target cells **Every cell in the body gets the same adrenaline in the blood. Why do only some cells respond?** ☐ Other cells destroy it ☐ The brain tells the other cells to ignore it ☐ Adrenaline only flows to the heart ☐ Only target cells have receptors that fit adrenaline ::: :::teacher-note **Answer:** Only target cells have receptors that fit adrenaline ::: :::keep-together ### The right tool **Growth over years is controlled by growth hormone, not nerves. Why is a hormone better for this job?** ☐ The effect needs to last a long time and reach cells all over the body ☐ Hormones are faster ☐ Growth is a reflex ☐ Nerves can't reach bones ::: :::teacher-note **Answer:** The effect needs to last a long time and reach cells all over the body ::: :::keep-together ### Which one? **A sprinter reacts to the starting gun. Which system carries the message to the leg muscles, and why?** ☐ Endocrine: a hormone in the blood reaches every leg muscle at once ☐ Both equally: every response uses both systems ☐ Endocrine: the race lasts a long time, so the effect must last ☐ Nervous: the response must be very fast and go to particular muscles ::: :::teacher-note **Answer:** Nervous: the response must be very fast and go to particular muscles ::: :::typical ## Elaborate: both at once :::keep-together **A car swerves towards you on your bike. Which part of your response is nervous and which is hormonal?** Groups: Nervous, Hormonal - You brake and steer away: {{field-15}} - Your heart is still racing five minutes later: {{field-15}} - Your hands are shaky as you ride home: {{field-15}} - You flinch: {{field-15}} ::: :::teacher-note **Answer:** You brake and steer away → Nervous; Your heart is still racing five minutes later → Hormonal; Your hands are shaky as you ride home → Hormonal; You flinch → Nervous ::: ::: :::wider ## Elaborate: insulin :::keep-together **After a meal, the pancreas releases insulin. Liver and muscle cells take up glucose from the blood. Which describes it?** ☐ The pancreas is the gland, insulin is the hormone, liver and muscle cells are targets ☐ Glucose is the hormone ☐ The liver is the gland, insulin is the target ☐ Insulin is a nerve impulse from the pancreas ::: :::teacher-note **Answer:** The pancreas is the gland, insulin is the hormone, liver and muscle cells are targets ::: ::: ## Evaluate: look back Write one sentence: "At first I thought… Now I think… because…" **Revision summary** - **Nervous system:** electrical impulses along neurons; very fast; short-lived; to one exact place. - **Endocrine system:** **hormones** released by **glands** into the **blood**; slower; longer-lasting; reach every cell but act only on **target cells** with matching receptors. - Many responses use both. ## Exit ticket :::keep-together **Give two differences between a nervous and a hormonal response.** {{lines-3}} ::: :::teacher-note **Answer:** Nerves: electrical, fast, short-lived, one place. Hormones: chemical in the blood, slower, longer-lasting, target cells everywhere. :::