14.1 Coordination and Response 2

2026 Syllabus Objectives

  1. State that electrical impulses travel along neurones
  2. Describe the mammalian nervous system in terms of:
    • (a) the central nervous system (CNS) consisting of the brain and the spinal cord
    • (b) the peripheral nervous system (PNS) consisting of the nerves outside of the brain and spinal cord
  3. Describe the role of the nervous system as coordination and regulation of body functions
  4. Identify in diagrams and images sensory, relay and motor neurones
  5. Describe a simple reflex arc in terms of: receptor, sensory neurone, relay neurone, motor neurone and effector
  6. Describe a reflex action as a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands)
  7. Describe a synapse as a junction between two neurones
  8. Describe the structure of a synapse, including the presence of vesicles containing neurotransmitter molecules, the synaptic gap and receptor proteins
  9. Describe the events at a synapse as:
    • (a) an impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap
    • (b) the neurotransmitter molecules diffuse across the gap
    • (c) neurotransmitter molecules bind with receptor proteins on the next neurone
    • (d) an impulse is then stimulated in the next neurone
  10. State that synapses ensure that impulses travel in one direction only

The Human Nervous System

https://cambridgeassistant.com

🔑 Key Concept: Coordination

Coordination is the process of ensuring that the actions of different parts of the body work together effectively. Animals need fast and efficient communication systems between their receptors (cells that detect stimuli) and effectors (parts of the body that respond to stimuli, such as muscles and glands).

Stimuli are changes in an organism's environment. For example:

  • Smelling good food cooking → salivary glands respond by secreting saliva
  • Touching something hot → pain receptors send impulses to arm muscles to contract and pull the hand away

Two Methods of Communication

Most animals have two methods of sending information from receptors to effectors:

  1. Nervous system (faster) - uses electrical impulses along nerves
  2. Endocrine system (slower) - uses chemical hormones

📌 The nervous system provides the fastest method of communication, essential for rapid responses to stimuli such as avoiding predators or catching prey.

Sign in to view full notes