The Eye - Coordination and Control - AQA GCSE Biology
Overview of the Nervous System
- Function: Enables humans to react to their surroundings and coordinate behavior.
- Components: Composed of millions of neurons using electrical impulses for rapid communication.
- Related Topics: Part of Biology focusing on Homeostasis and Response.
Structure and Function of the Eye
- Eye as a Sense Organ: Contains receptors sensitive to light intensity and color.
- Key Structures and Their Functions:
- Cornea: Refracts light, bending it as it enters the eye.
- Iris: Controls the amount of light entering the pupil.
- Lens: Further refracts light to focus it on the retina.
- Retina: Contains light receptors.
- Optic Nerve: Carries impulses from the eye to the brain.
- Sclera: Tough, white outer layer protecting the eye from injury.
The Retina
- Pathway of Light: Light travels through the eyeball to the retina.
- Types of Light Receptors:
- Rods: More sensitive to light, useful for seeing in dim conditions.
- Cones: Three types, responsible for color vision.
The Pupil Reflex
- Function: Controls the amount of light entering the eye via reflex action.
- Mechanism: The size of the pupil changes in response to light intensity, controlled by muscles in the iris.
Additional Resources
- Learn More: Dr. Alex Lathbridge discusses the structure of the brain and eyes. Listen to the full series on BBC Sounds.
Further Study and Guides
- Explore other topics such as the human endocrine system, hormones in human reproduction, homeostasis, and plant hormones.
- Access sample exam questions on homeostasis and response.
Related Links
This summary captures the essential information regarding the eye’s role in coordination and control within the nervous system as outlined in the AQA GCSE Biology curriculum.