Starter: Complete the following past exam question:

1. Title: Responding to Change Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Starter: • Complete the following past exam question: Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

2. The Nervous System Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? • The primary goal of the nervous system is to enable you to react to your surroundings and co-ordinate your behaviour. Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

3. The Nervous System Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? • Changes in your surroundings (stimuli) are picked up by cells known as receptors Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

4. The Nervous System Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? • Receptor cells are clustered together in special sense organs, like your eyes or skin. Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

5. The Nervous System Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

6. How Your Nervous System Works • Once a sensory receptor detects a stimulus, the information is sent in the form of an electrical impulse along cells known as neurons. Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

7. How Your Nervous System Works • Neurons are usually arranged in bundles of round a thousand, known as a nerve. Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

8. How Your Nervous System Works • The impulse travels along the nerve until it reaches the central nervous system (CNS) Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

9. How Your Nervous System Works • Sensory Neurons carry nerve impulses from receptors in the body to the CNS. • Motor Neurons carry nerve impulses from the CNS to the rest of the body Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

10. How Your Nervous System Works • Impulses that travel along motor neurones causeeffector organs like muscles or glands to respond. • Muscles contract and glands secrete chemical substances. Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs

11. Task 1. Your ........ system carries fast....... impulses. Changes in the .............. are picked up by your................ Learning Objectives Why do you need a nervous system? What is a receptor? How do you respond to changes in your surroundings? 2. Complete: Receptor  ___  CNS  ___ Effector 3. Explain what happens in your nervous system when you see a piece of chocolate and eat it. Key Words: stimuli, receptors, impulses, sense organs, CNS, neurons, nerves, secretory organs