The human nervous system key terms

nervous system

A complex network of neurones that detects stimuli, coordinates responses, and enables humans to react to their surroundings.

coordination

The process by which the nervous system organizes and integrates sensory information to produce appropriate behavioral responses.

sensory neurone

A type of neurone that carries impulses from receptor cells to the central nervous system (CNS) after detecting stimuli.

motor neurone

A type of neurone that transmits impulses from the central nervous system (CNS) to effectors, such as muscles or glands, to initiate a response.

central nervous system

The part of the nervous system that consists of the brain and spinal cord, responsible for processing information and coordinating responses.

spinal cord

A long, thin bundle of nervous tissue that extends from the brain down the back, transmitting signals between the brain and the rest of the body.

effectors

In Structure and function, effectors means muscles and glands that bring about responses in the body. This matters in The human nervous system because it supports the learning objective to describe muscles and glands as effectors that bring about responses, with muscles contracting and glands secreting hormones. Use effectors only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

glands

Glands are effectors that produce and release chemical substances. In the nervous-system reflex pathway, glands are contrasted with muscles: muscles contract, while glands secrete substances such as hormones to bring about a response.

reflex action

An automatic and rapid response to a stimulus that occurs without conscious thought, designed to protect the body.

automatic response

A quick reaction to a stimulus that does not involve conscious decision-making, allowing for immediate protective actions.

reflex arc

The neural pathway that mediates a reflex action, consisting of a stimulus, receptor, sensory neurone, relay neurone, motor neurone, and effector.

motor neurone

A type of neurone that transmits impulses from the central nervous system to effectors, such as muscles or glands, to bring about a response.

synapse

A junction between two neurones where signals are transmitted across gaps through neurotransmitters.

neurotransmitter

A chemical substance released at a synapse that transmits signals from one neurone to another.

reflex arc

A neural pathway that controls a reflex action, consisting of a stimulus, receptor, sensory neurone, relay neurone, motor neurone, and effector.

motor neurone

A type of neurone that transmits impulses from the central nervous system to effectors, such as muscles or glands, to initiate a response.

nervous system

A complex network of neurones that transmits signals between different parts of the body, enabling rapid communication and coordination of responses.

hormonal coordination

A slower form of communication in the body that involves the release of hormones into the bloodstream to regulate various physiological processes.

reaction time

The time taken to respond to a stimulus, often measured in experiments to assess the efficiency of the nervous system.

data interpretation

The process of analyzing and making sense of data collected from experiments, particularly in the context of nervous system responses.

reaction time

In Structure and function, reaction time means the time taken to respond to a stimulus, often measured in milliseconds. This matters in The human nervous system because it supports the learning objective to translate reaction-time information between numerical and graphical forms. Use reaction time only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

data representation

The method of displaying information in numerical or graphical formats to facilitate analysis.

reaction time

In Structure and function, reaction time means the duration taken for an organism to respond to a stimulus. This matters in The human nervous system because it supports the learning objective to carry out Required Practical 7 by planning and performing an investigation into the effect of a factor on human reaction time. Use reaction time only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

required practical

A structured investigation designed to explore the effect of a specific factor on human reaction time.

control variables

Factors that are kept constant during an experiment to ensure that the results are valid and reliable.

mean values

The average of a set of numbers, calculated by adding them together and dividing by the number of values, used to summarize data in experiments.

neurones

Specialized cells that transmit nerve impulses, forming the basic building blocks of the nervous system.

complex behaviour

Actions or reactions of an organism that involve multiple processes and interactions within the brain.

cerebral cortex

The region of the brain associated with consciousness, intelligence, memory, and language.

brain

In The brain (biology only), brain means an organ made of billions of interconnected neurones that controls complex behaviour. This matters in The human nervous system because it supports the learning objective to identify the cerebral cortex as the brain region associated with consciousness, intelligence, memory and language. Use brain only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.