Reflex

• What is a reflex?

  A stereotyped, involuntary, rapid response
• What are the general functions of reflexes?

  • Protective
  • Postural control
  • Homeostasis
• What are the components of a reflex arc?

  Sensory receptor, afferent, CNS, efferent, effector
• What are the neural components involved in reflexes?

  Sensory receptors, afferents, CNS neurons, interneurons
• What is the role of sensory receptors in reflexes?

  They detect stimuli and initiate reflex actions
• What is the function of afferent neurons in a reflex arc?

  They carry sensory information to the CNS
• What is the role of interneurons in reflexes?

  They integrate signals within the CNS
• What do efferent neurons do in a reflex arc?

  They carry commands from the CNS to effectors
• What are effectors in the context of reflexes?

  Muscles or glands that respond to commands
• What is a reflex?

  A stereotyped, involuntary, and rapid response
• What are the general functions of reflexes?

  1. Protective, 2) Postural control, 3) Homeostasis
• What are the neural components of a reflex arc?

  Sensory receptors, afferent neurons, CNS neurons, interneurons, efferent neurons, effectors
• How do simple stretch reflexes (myotatic reflexes) work?

  They adjust the degree of muscle contraction to maintain posture
• What is the knee jerk reflex?

  A simple stretch reflex in the spinal cord
• What is the reverse (inverse) myotatic reflex?

  A reflex that causes flexor muscles to contract and extensor muscles to relax
• What is the crossed extensor reflex?

  A reflex that causes the extensor muscles of the opposite limb to contract
• What are the recommended readings for this topic?

  Silverthorn: Human Physiology, Bear, Connors and Paradiso: Neuroscience, general physiology texts
• What are the key components of the reflex arc and how do they interact?

  • Sensory receptors detect a stimulus
  • Afferent neurons transmit the sensory information to the CNS
  • CNS neurons and interneurons integrate the information
  • Efferent neurons transmit the motor command from the CNS
  • Effectors (muscles, glands) respond to the motor command
• How do different types of reflexes (e.g. stretch, inverse, crossed extensor) differ in their neural pathways and functions?

  • Stretch reflexes (myotatic) adjust muscle contraction to maintain posture
  • Inverse (reverse) myotatic reflexes cause flexor muscles to contract and extensors to relax
  • Crossed extensor reflexes cause the extensor muscles of the opposite limb to contract