Lecture on Reaction Time and the Nervous System

Overview

• Lecture focuses on reaction time required practical
• Sections include:
  1. Organization of the Nervous System
  2. Reflex Arcs
  3. The Required Practical
  4. Possible Exam Questions
• Encouragement to check the description for worksheets and answers

Organization of the Nervous System

• Stimulation of Brain:
  • Different parts of the brain can produce sensory experiences (e.g., hearing sounds, tasting)
• Connection of Brain and Sense Organs:
  • Brain regions are linked to specific sense organs (e.g., tongue, ears)
• Flowchart of Nervous System:
  • Stimuli: Environmental changes (e.g., sound waves)
  • Receptors: Detect stimuli and send electrical impulses
  • Coordinator: Central Nervous System (CNS) processes impulses
  • Sensory Neurons: Connect receptors to CNS
  • Motor Neurons: Connect CNS to effectors (muscles or glands)

Reflex Arcs

• Importance of Reflexes:
  • Rapid, automatic responses not involving conscious brain
  • Allows quick reactions to avoid damage
• Reflex Arc Pathway:
  • Stimulus: E.g., fire causing heat
  • Receptor: Heat and pain receptors trigger sensory neuron
  • Sensory Neuron: Carries impulse to spinal cord
  • Relay Neuron: Transfers signal within spinal cord
  • Motor Neuron: Stimulates effectors (muscles/glands)
  • Response: E.g., hand withdrawal from fire
• Synapse:
  • Gap between neurons where impulses are transferred via chemicals

Required Practical: Reaction Time

• Concept of Reaction Time:
  • Measure of time taken to react to a stimulus
• Experiment Steps:
  1. Sit with weaker hand on table
  2. Partner holds ruler; drops it without warning
  3. Catch ruler; measure distance fallen
  4. Record and repeat for accuracy
  5. Convert distance to reaction time
  6. Repeat with partner
• Variations of Practical:
  • Practice: Check if practice reduces reaction time
  • Caffeine: Test if caffeine (a stimulant) reduces reaction time
  • Possible variables: age, gender, distractions

Possible Exam Questions

• Experiment Improvements:
  • Increase repeats and calculate mean
  • Use larger sample size
  • Utilize computer programs for accuracy
• Explain Anomalies:
  • Identify anomalies, calculate mean, explain causes
  • Lower results: anticipation of drop
  • Higher results: distractions

Closing Remarks

• Encouragement to review worksheets
• Emphasis on studying and revising over holidays
• Reminder of upcoming biology exams
• Call to action to like, subscribe, and engage with content