Overview
The lecture explains reflex reactions, detailing how they work, their pathways, and the difference between simple and conditioned reflexes.
Reflex Reactions
- Reflex reactions are immediate, unconscious responses to stimuli that protect the body.
- They help increase survival chances by enabling quick responses to danger, such as moving away from a hot surface.
- Reflex responses do not initially involve conscious thought.
Reflex Arc Pathway
- The reflex arc bypasses the brain and routes nerve signals through the spinal cord for a rapid response.
- The pathway includes: a stimulus activating a receptor, a signal sent via a sensory neuron, processed in the spinal cord, then sent via a motor neuron to an effector.
- The brain receives the message after the reflex action, allowing further voluntary action if needed.
- The short pathway makes the reaction much faster than if the brain was involved from the start.
Types of Reflexes
- Simple reflexes are innate and involve no conscious awareness during the initial response.
- Conditioned reflexes are learned through prior experience and involve a subconscious response.
- Pavlov’s dogs experiment is an example of a conditioned reflex, where the dogs salivated to a bell after learning it signaled food.
Key Terms & Definitions
- Reflex Reaction — Immediate, involuntary response to a stimulus without conscious thought.
- Reflex Arc — The nerve pathway involved in a reflex action that typically bypasses the brain.
- Simple Reflex — Inborn, automatic response to a stimulus.
- Conditioned Reflex — Learned reflex response developed through association or experience.
- Stimulus — A change in the environment that causes a response.
- Receptor — Structure that detects a stimulus.
- Effector — Muscle or gland that carries out the response.
Action Items / Next Steps
- Review nervous system components: sensory neuron, motor neuron, relay neuron.
- Study examples of both simple and conditioned reflexes.