Reflex

• Monosynaptic reflex


  • Stretch reflex: when a skeletal muscle with an intact nerve supply is stretched, it contracts
• Spindle muscle is the sense organ involved in the stretch reflex
• Monosynaptic reflex


  • Examples: knee jerk, ankle jerk muscle spindle
• Reflex


  Basic unit of integrated neural activity
• Monosynaptic arc


  Reflex arc with a single synapse between the afferent and efferent neurons
• Reflex arc


  Components: Receptor Organ, Afferent fiber, Synapse, Efferent fiber, Effector organ
• Polysynaptic arc is a reflex arc in which one or more interneurons are interposed between the afferent and efferent neurons
• Withdrawal reflex


  Typical polysynaptic reflex that occurs in response to a noxious and usually painful stimulation of the skin, subcutaneous tissue, and muscle
• Touch receptors adapt rapidly and are most numerous in the skin of the fingers, lips, face, and trunk
• There are 2 types of pain: superficial pain (well-localized) and deep pain (poorly localized, nauseating)
• Referred pain is felt at an area away from the actual source of pain due to the activation of the sympathetic nervous system
• Proprioception receptors provide information about the position of the body in space and are located in and around the joints
• Visceral pain is poorly localized, unpleasant, and associated with various symptoms like nausea, vomiting, and changes in blood pressure
• Cutaneous, Deep, and Visceral Sensation


  • Touch
  • Proprioception
  • Temperature
  • Pain
  • Visceral Pain
  • Referred Pain
  • Itch
  • Tickle
• There are 2 types of temperature sense organs: those responding to temperatures above and below body temperature
• Itching is produced by repetitive low-frequency stimulation or by chemical agents
• Tickling is produced by very mild stimulation where something is moving across the skin