International A Level Biology / The nervous system and neurones

How rods detect light

Edexcel International A Level Biology (YBI11), chapter 23: The nervous system and neurones, specification point 8.8. Part of the full course.

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Rod cells detect light because light changes rhodopsin and switches off the rod's steady release of neurotransmitter. This removes inhibition of the bipolar neurone, allowing an action potential to form in the optic neurone.

More lessons in The nervous system and neurones

• Sensory, relay and motor neurones
• From stimulus to response
• The spinal reflex arc
• The resting potential
• The action potential
• How an impulse travels: local circuits and saltatory conduction
• How a synapse works
• How the pupil dilates and contracts
• How drugs affect nerve transmission
• Habituation