Biology Matters for GCE ‘O’ Level - The Nervous System and The Eye

Vocabulary flashcards covering key terms and concepts related to the nervous system and eye structure and function.

Nervous System

The system that coordinates and regulates bodily functions, consisting of the brain, spinal cord, and nerves.

Central Nervous System (CNS)

Consists of the brain and spinal cord; it manages essential body functions by receiving sensory information and coordinating responses.

Peripheral Nervous System (PNS)

Connects the CNS to the rest of the body; extends nerves to organs and muscles.

Neuron

Specialized cell that transmits chemical and electrical information in the body.

Neurotransmitters

Chemicals that relay signals between neurons and bodily tissues, including adrenaline and dopamine.

Synapse

The junction between two neurons where neurotransmitters are released to transmit nerve impulses.

Reflex Action

An immediate response to a specific stimulus without conscious control.

Cerebral Reflex

Reflex actions that are controlled by the brain.

Spinal Reflex

Reflex actions that are controlled by the spinal cord.

Photoreceptors

Cells in the retina that detect light; consist of rods and cones for vision in dim or bright light.

Pupil Reflex

A reflex action that changes the size of the pupil in response to light intensity to protect the retina.

Accommodation

The adjustment of the lens in the eye to focus on near or distant objects.

Cornea

The transparent layer at the front of the eye that refracts light rays into the eye.

Iris

A circular sheet of muscles that controls the size of the pupil and the amount of light entering the eye.

Ciliary Muscles

Muscles that control the curvature of the lens for focusing.

Vitreous Humour

A jelly-like substance in the eye that helps maintain shape and refract light onto the retina.

Aqueous Humour

A watery fluid in the front of the eye that helps maintain internal pressure and refract light.

Lens

An elastic, biconvex structure that changes shape to focus light on the retina.