The human nervous system key terms

myopia

A vision condition where distant objects appear blurred because they are focused in front of the retina.

retina

The light-sensitive layer at the back of the eye that contains receptor cells and is responsible for converting light into neural signals.

hyperopia

A vision condition where distant objects are seen clearly, but close ones are blurred, caused by light focusing behind the retina.

long sightedness

Another term for hyperopia, indicating difficulty in seeing nearby objects clearly due to improper light focus in the eye.

spectacle lenses

Optical devices worn in front of the eyes to correct vision defects such as myopia and hyperopia by altering the path of light entering the eye.

refraction

The bending of light as it passes through different mediums, which is essential for focusing images on the retina.

myopia

A vision condition where distant objects are focused in front of the retina, causing blurred vision for far away objects.

hyperopia

A vision condition where near objects are focused behind the retina, resulting in difficulty seeing close objects clearly.

contact lenses

In The eye (biology only), contact lenses means thin lenses placed directly on the surface of the eye to correct vision defects. This matters in The human nervous system because it supports the learning objective to evaluate the use of contact lenses, laser surgery and replacement lens surgery to correct vision defects. Use contact lenses 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.

laser surgery

A medical procedure that uses focused light to reshape the cornea and correct vision problems.

thermoregulatory centre

In Control of body temperature (biology only), thermoregulatory centre means the part of the brain that monitors and regulates body temperature. This matters in The human nervous system because it supports the learning objective to describe body temperature as an internal condition monitored and controlled by the thermoregulatory centre in the brain. Use thermoregulatory centre 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.

body temperature

An internal condition that is maintained within a narrow range to ensure proper physiological function.

thermoregulatory centre

A part of the brain that monitors and regulates body temperature by receiving signals from temperature receptors.

receptors

Specialized cells that detect changes in temperature and send impulses to the thermoregulatory centre.

temperature receptors

Specialized nerve endings in the skin that detect changes in temperature and send impulses to the thermoregulatory centre.

thermoregulatory centre

A region in the brain that monitors and regulates body temperature by processing signals from temperature receptors.

vasodilation

The widening of blood vessels, which increases blood flow to the skin and helps to dissipate heat when body temperature is too high.

sweating

The process of producing moisture on the skin's surface, which cools the body through evaporation when body temperature rises.

vasoconstriction

The narrowing of blood vessels to reduce blood flow and conserve body heat when the temperature is too low.

shivering

An involuntary muscle contraction that generates heat to help raise body temperature when it is too low.

vasodilation

The widening of blood vessels, which increases blood flow to the skin and helps to dissipate heat when body temperature is too high.

sweating

The process by which the body releases moisture through sweat glands, which cools the body as the sweat evaporates from the skin surface.

vasoconstriction

The narrowing of blood vessels, which reduces blood flow to the skin and helps to conserve body heat when temperatures are low.

shivering

A rapid, involuntary contraction of muscles that generates heat to raise body temperature when it is too low.

thermoregulation

The process by which the body maintains its internal temperature within a narrow range despite external temperature changes.

heat transfer

The movement of thermal energy from one object or substance to another, which can occur through conduction, convection, or radiation.