Biology

• What is the function of the sclera in the eye?

  It protects the eye
• What role does the iris play in the eye?

  It controls how much light enters the eye
• What is the purpose of the pupil in the eye?


  It regulates the amount of light entering the eye
• What is the function of the cornea?

  It protects the opening and refracts light
• What is the role of the ciliary muscle in the eye?

  It changes the shape of the lens
• What does the retina contain?

  It contains receptor cells (rods and cones)
• How do rods and cones in the retina function?

  They detect light
• What is the function of the lens in the eye?

  It focuses light on the retina
• What does the optic nerve do?

  It carries impulses to the brain
• Which part of the brain receives impulses from the optic nerve?

  The occipital cortex
• What are the main components of the eye and their functions?

  • Sclera: Protects the eye
  • Iris: Controls light entry
  • Pupil: Regulates light amount
  • Cornea: Protects and refracts light
  • Ciliary muscle: Changes lens shape
  • Retina: Contains receptor cells (rods and cones) that detect light
  • Lens: Focuses light on the retina
  • Optic nerve: Carries impulses to the brain (occipital cortex)
• What are synapses?

  Gaps between neurones
• Why can't an electrical impulse flow across a synapse?

  Because there is a gap between the neurones
• What stimulates the release of neurotransmitters?

  An electrical impulse
• What happens to neurotransmitters after they are released into the synapse?

  They diffuse across the synapse
• How does a dendrite respond to neurotransmitters?

  It detects the neurotransmitter to generate and continue the electrical impulse
• What effect do synapses have on the speed of an impulse?

  They slow down the impulse
• What is the direction of impulse flow at a synapse?

  It ensures the impulse goes in one way direction
• Describe how the arrival of an impulse at the end of one neurone can cause an impulse in a neighbouring neurone.

  • Transmission impulse triggers the release of neurotransmitter
  • Neurotransmitter is released into the synapse
  • Next neurone detects the neurotransmitter
• What is the effect of the number of synapses on impulse transmission?

  It slows down the effects
• What is the role of the axon terminal in synaptic transmission?

  It releases neurotransmitters into the synapse
• How do myelin sheaths affect the speed of an impulse?

  They speed up the impulse
• What is released into the synapse during impulse transmission?

  Neurotransmitter