The document discusses two systems that help coordinate the body's activities and maintain homeostasis: 1) The nervous system, which uses electrical impulses traveling along nerves to communicate information around the body rapidly. It is coordinated by the central nervous system (brain and spinal cord). 2) The endocrine system, which uses hormones as chemical messengers to coordinate bodily functions.

1. Co-ordination and Homeostatis Two systems help to coordinate the activities and development of our bodies and keep our internal environment constant . The nervous system, using electrical impulses, and endocrine system, using chemicals called hormones.

2. objectives know that the nervous system uses nerves to communicate information rapidly around the body coordinated by the central nervous system (brain and spinal cord). describe the passage of the nerve impulse through a reflex arc.

3. keywords Neurone Sensory Reflex Motor Intermediate / Relay Synapse spinal cord

4. The nervous system There are 2 parts The CNS – central nervous system The PNS – peripheral nervous system CNS is the brain and spinal cord PNS are the nerves

5. Sensory Neurones Carry information from sense organs (skin, eye, ear, nose, tongue) To the brain

6. Motor neurones Carry information from the brain To effectors (muscles and glands)

7. Stimulus Coordinator Effector response

8. How sensitive are you?

9. Plenary True or false? Nerves are the longest cells of the body The PNS is the brain and spinal cord Motor neurones carry information to the brain Reflexes involve no thinking The skin is the biggest sense organ

10. Reflex arc