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Questions and Answers
Where are the neuronal cell bodies located in somatic motor pathways?
Where are the neuronal cell bodies located in somatic motor pathways?
Where does the axon of the upper motor neuron usually project to synapse onto?
Where does the axon of the upper motor neuron usually project to synapse onto?
In the central nervous system (CNS), how are the pathways organized?
In the central nervous system (CNS), how are the pathways organized?
Where does processing and modulation occur within the pathways?
Where does processing and modulation occur within the pathways?
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Where is the cell body of the 2° neuron located?
Where is the cell body of the 2° neuron located?
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Which somatosensory modality is associated with the fasciculus cuneatus?
Which somatosensory modality is associated with the fasciculus cuneatus?
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Where do the axons of the 2° neurons decussate?
Where do the axons of the 2° neurons decussate?
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Where are the cell bodies of the 3° neurons located?
Where are the cell bodies of the 3° neurons located?
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Which structure do the 1° neurons ascend in for the lower body somatosensory information?
Which structure do the 1° neurons ascend in for the lower body somatosensory information?
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Where do the axons of the 2° neurons ascend contralaterally?
Where do the axons of the 2° neurons ascend contralaterally?
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Which part of the brain do the 3° neurons project to?
Which part of the brain do the 3° neurons project to?
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Which somatosensory modality is associated with the spinothalamic tract?
Which somatosensory modality is associated with the spinothalamic tract?
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Which pathway originates in the motor cortex and controls skilled, asymmetric limb movements?
Which pathway originates in the motor cortex and controls skilled, asymmetric limb movements?
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What type of neurons are lower motor neurons (LMNs) typically?
What type of neurons are lower motor neurons (LMNs) typically?
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Which type of sensation involves touch, pressure, vibration, conscious proprioception, nociception, and temperature?
Which type of sensation involves touch, pressure, vibration, conscious proprioception, nociception, and temperature?
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Where are the 1° neurons of somatosensory pathways located?
Where are the 1° neurons of somatosensory pathways located?
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Which pathway carries touch, vibration, proprioception, pressure, pain, and temperature signals?
Which pathway carries touch, vibration, proprioception, pressure, pain, and temperature signals?
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What type of neurons form bilaterally paired motor columns in the brainstem and spinal cord?
What type of neurons form bilaterally paired motor columns in the brainstem and spinal cord?
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Which tract projects to the postcentral gyrus for conscious sensation and has somatotopic organization along the spinal cord?
Which tract projects to the postcentral gyrus for conscious sensation and has somatotopic organization along the spinal cord?
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What region can lesions result in distinct neurological presentations over time?
What region can lesions result in distinct neurological presentations over time?
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What do descending pathways from upper motor neurons (UMNs) innervate?
What do descending pathways from upper motor neurons (UMNs) innervate?
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Which pathway is responsible for maintaining posture?
Which pathway is responsible for maintaining posture?
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Which type of neurons innervate lower motor neurons (LMNs)?
Which type of neurons innervate lower motor neurons (LMNs)?
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What type of information do sensory pathways carry from receptors to the central nervous system?
What type of information do sensory pathways carry from receptors to the central nervous system?
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Study Notes
Neural Pathways and Somatosensory Pathways in the CNS
- Lower motor neurons (LMNs) from the brainstem and spinal cord synapse onto skeletal muscles for voluntary movement.
- LMNs are the "final common pathway" for muscle control and are typically large neurons with extensive dendritic trees.
- LMNs form bilaterally paired motor columns in the brainstem and spinal cord and control axial and distal limb muscles.
- Descending pathways from upper motor neurons (UMNs) innervate LMNs and include lateral and medial pathways for controlling limb muscles and maintaining posture, respectively.
- The lateral corticospinal tract (LCST) originates in the motor cortex and controls skilled, asymmetric limb movements.
- Sensory pathways carry information from receptors to the central nervous system, including interoceptors and exteroceptors.
- Somatic sensation involves touch, pressure, vibration, conscious proprioception, nociception, and temperature.
- Somatosensory pathways consist of a three-neuron chain, with pseudounipolar 1° neurons located in the PNS and 2° neurons in the dorsal horn of the spinal cord or brainstem nucleus.
- Dorsal columns and spinothalamic tract are key pathways for somatosensory information transmission, carrying touch, vibration, proprioception, pressure, pain, and temperature signals.
- The spinothalamic tract projects to the postcentral gyrus for conscious sensation and has somatotopic organization along the spinal cord.
- Lesions in cervical intramedullary and extramedullary regions can result in distinct neurological presentations over time.
- The 1° neuron of somatosensory pathways is located in the PNS, travels through peripheral and spinal nerves, and has its cell body in the dorsal root ganglion.
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Description
Test your knowledge of neural pathways and somatosensory pathways in the central nervous system with this quiz. Explore topics such as lower motor neurons, descending pathways, sensory pathways, somatic sensation, and key pathways for somatosensory information transmission. Gain a deeper understanding of the organization and function of these crucial neural pathways.
