Many human actions are rapid and automatic, occurring without conscious thought. These are known as reflexes.
Which two of the following actions are examples of reflex actions?
- Automatically blinking when an object rapidly approaches the eye
- Reaching out to pick up a ringing phone
- The sudden knee-jerk extension of the leg when the patellar tendon is tapped
- Choosing to whistle a tune while walking down the street
- Pausing to read a warning sign on a gate
The figure below shows how the shape of the lens in the human eye changes by reflex action (accommodation) from State YState\ YState Y to State XState\ XState X.
Name one change in a visual stimulus that would cause the eye to transition from State YState\ YState Y to State XState\ XState X.
Structure PStructure\ PStructure P helps control the shape of the lens. Name Structure PStructure\ PStructure P.
Describe how Structure PStructure\ PStructure P and the suspensory ligaments cause the change in the shape of the lens from State YState\ YState Y to State XState\ XState X.
A person accidentally pricks their finger on a sharp rose thorn and immediately withdraws their hand in a reflex action.
Describe how the receptor, the three neurones (sensory, relay, and motor), the synapses, and the effector work together to coordinate this reflex response.