This definitions covers Key Definitions within Nervous System for GCSE Biology. Topic 2: Nervous System It is section 9 of 14 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 9 of 14
Practice
15 questions
Recall
20 flashcards
Key Definitions
Central nervous system (CNS): The brain and spinal cord; the coordination centre that processes information from sensory neurones and sends instructions to motor neurones.
Sensory neurone: A nerve cell that carries electrical impulses from sensory receptors toward the CNS.
Relay neurone: A nerve cell found within the CNS that connects sensory neurones to motor neurones and processes information.
Motor neurone: A nerve cell that carries electrical impulses from the CNS to effectors (muscles or glands).
Synapse: The tiny gap between two neurones across which neurotransmitters diffuse to transmit a signal from one neurone to the next.
Neurotransmitter: A chemical released from the end of one neurone that diffuses across the synapse and binds to receptor proteins on the next neurone, triggering a new impulse.
Receptor (nervous system): A specialised cell or cell ending that detects a specific stimulus (e.g. light, pressure, temperature) and converts it into an electrical impulse.
Effector: A muscle or gland that responds to instructions from the CNS, producing a movement or secretion.