Lesson 4: Reflexes & Sensory Input (PNS & Feedback)
Duration of Days: 4
Lesson Objective
Design an investigation to test human reaction time and sensory thresholds.
Why do we pull our hand away from fire before we "feel" the pain? How does the body maintain balance?
Reflex Arc, Sensory Neuron, Interneuron, Motor Neuron, Homeostasis, Thermoreceptor.
HS-LS1-3 (Feedback mechanisms)
Analyzing experimental variables and data tables in a lab setting.
Description: Students conduct a "Reaction Time Lab" to compare voluntary vs. involuntary responses.
Purpose: To observe feedback loops in action.
DOK 4.
The effects of texting-while-driving on the nervous system's processing speed.
Thinking reflexes go to the brain first. (Correction: Reflexes are processed in the spinal cord for speed).
Choice of data collection: Students can use digital "click tests" or physical "ruler drop" tests.
Formal Lab Report analyzing how sensory input (sight vs. sound) changes reaction speed.
Meter sticks, rubber reflex hammers, online reaction timers.