Study Question Fifteen

• Q15. Apply these concepts to information flow along the spinal cord for a simple spinal cord reflex.
• Information Flow in a Simple Spinal Cord Reflex

  • First: Stimulus detection. A sensory receptor detects a stimulus.
• Information Flow in a Simple Spinal Cord Reflex

  • First: Stimulus detection. A sensory receptor detects a stimulus.
• Information Flow in a Simple Spinal Cord Reflex

  • First: Stimulus detection. A sensory receptor detects a stimulus.
• Information Flow in a Simple Spinal Cord Reflex

  • Second: Afferent Pathway. The sensory information is transmitted by afferent (sensory) neurons that have their cell bodies located in the dorsal root ganglion. The axons of these sensory neurons enter the spinal cord through the dorsal root and synapse in the posterior (dorsal) horn of the gray matter.
• Information Flow in a Simple Spinal Cord Reflex

  • Second: Afferent Pathway. The sensory information is transmitted by afferent (sensory) neurons that have their cell bodies located in the dorsal root ganglion. The axons of these sensory neurons enter the spinal cord through the dorsal root and synapse in the posterior (dorsal) horn of the gray matter.
• Information Flow in a Simple Spinal Cord Reflex

  • Second: Afferent Pathway. The sensory information is transmitted by afferent (sensory) neurons that have their cell bodies located in the dorsal root ganglion. The axons of these sensory neurons enter the spinal cord through the dorsal root and synapse in the posterior (dorsal) horn of the gray matter.
• Information Flow in a Simple Spinal Cord Reflex

  • Third: Integration Center. In the posterior horn, the sensory neurons synapse with interneurons or directly with lower motor neurons located in the anterior (ventral) horn of the gray matter. This is the integration center where the reflex arc is completed.
• Information Flow in a Simple Spinal Cord Reflex

  • Third: Integration Center. In the posterior horn, the sensory neurons synapse with interneurons or directly with lower motor neurons located in the anterior (ventral) horn of the gray matter. This is the integration center where the reflex arc is completed.
• Information Flow in a Simple Spinal Cord Reflex

  • Third: Integration Center. In the posterior horn, the sensory neurons synapse with interneurons or directly with lower motor neurons located in the anterior (ventral) horn of the gray matter. This is the integration center where the reflex arc is completed.
• Information Flow in a Simple Spinal Cord Reflex

  • Fourth: Efferent Pathway. The activated lower motor neurons send their axons out of the spinal cord through the ventral root. These motor neurons may also be influenced by descending pathways from the brain, but for a simple reflex, this connection is minimal.
• Information Flow in a Simple Spinal Cord Reflex

  • Fourth: Efferent Pathway. The activated lower motor neurons send their axons out of the spinal cord through the ventral root. These motor neurons may also be influenced by descending pathways from the brain, but for a simple reflex, this connection is minimal.
• Information Flow in a Simple Spinal Cord Reflex

  • Fourth: Efferent Pathway. The activated lower motor neurons send their axons out of the spinal cord through the ventral root. These motor neurons may also be influenced by descending pathways from the brain, but for a simple reflex, this connection is minimal.
• Information Flow in a Simple Spinal Cord Reflex

  • Fifth: Effector Response. The axons of the motor neurons travel to the target muscle (effector), where they release neurotransmitters at the neuromuscular junction, causing the muscle to contract and the body part to withdraw from the stimulus.
• Information Flow in a Simple Spinal Cord Reflex

  • Fifth: Effector Response. The axons of the motor neurons travel to the target muscle (effector), where they release neurotransmitters at the neuromuscular junction, causing the muscle to contract and the body part to withdraw from the stimulus.
• Information Flow in a Simple Spinal Cord Reflex

  • Fifth: Effector Response. The axons of the motor neurons travel to the target muscle (effector), where they release neurotransmitters at the neuromuscular junction, causing the muscle to contract and the body part to withdraw from the stimulus.
• • Dorsal root ganglion contains sensory neuron cell bodies.
  • Dorsal roots bring sensory information into the spinal cord.
  • Posterior horn processes sensory input.
  • Anterior horn contains lower motor neurons that trigger the response.
  • Ventral roots carry motor commands to effectors (muscles).
  • White matter columns are involved in relaying information to and from the brain.
• • Dorsal root ganglion contains sensory neuron cell bodies.
  • Dorsal roots bring sensory information into the spinal cord.
  • Posterior horn processes sensory input.
  • Anterior horn contains lower motor neurons that trigger the response.
  • Ventral roots carry motor commands to effectors (muscles).
  • White matter columns are involved in relaying information to and from the brain.