Somatic sensations

• What is the spinothalamic system responsible for?

  Pain, temperature, and light touch
• What does the medial lemniscus system process?

  Fine and discriminative touch, vibration, proprioception
• How do the fibers of the spinothalamic system cross?

  They cross at the spinal level
• Where do the fibers of the medial lemniscus system cross?

  In the caudal medulla
• What is the anterolateral system also known as?

  Spinothalamic tract
• What type of touch does the dorsal column system process?

  Fine and discriminative touch
• What is the role of Meissner corpuscles?

  Touch receptors
• What do Paccinian corpuscles detect?

  Vibration
• What do muscle spindles detect?

  Proprioception
• What is the first-order neuron in the medial lemniscus pathway?

  Spinal ganglia or trigeminal ganglia
• Where do second-order neurons synapse in the medial lemniscus pathway?

  Gracilis and cuneate nucleus
• What is the role of the VPL of thalamus?

  Relay sensory information to the cortex
• What is the pathway overview for first-order neurons?

  They detect stimuli and send signals to the spinal cord
• What happens during synapse and decussation?

  First-order neurons synapse with second-order neurons
• Where do fibers ascend after crossing in the spinothalamic tract?

  In the lateral funiculus of the spinal cord
• What is the somatotopic organization of the spinothalamic tract?

  Segmental organization from medial to lateral
• What does the anterior spinothalamic tract carry?

  Information about crude touch
• What does the lateral spinothalamic tract convey?

  Pain and temperature
• What is the trigeminal pathway responsible for?

  Carrying somatosensory information from the face
• What types of sensations does the trigeminal pathway transmit?

  Fine touch, pressure, vibration, pain, temperature
• Where do sensory inputs from the face enter the brain?

  At the level of the pons
• What is the function of the trigeminal nerve?

  Provide tactile, proprioceptive, and nociceptive afference
• What is the trigeminal ganglion analogous to?

  Dorsal root ganglia of the spinal cord
• What are the three major branches of the trigeminal nerve?

  Ophthalmic, maxillary, mandibular nerves
• What is the role of thalamic nuclei?

  Send information to specific areas in the cortex
• What types of receptors are involved in the spinothalamic tract?

  Mechanoreceptors, thermoreceptors, nociceptors
• What is the first-order neuron in the spinothalamic tract?

  Spinal ganglion or trigeminal ganglion
• Where do second-order neurons synapse in the spinothalamic tract?

  Dorsal horn of the spinal cord
• What is the third-order neuron in the spinothalamic tract?

  Thalamus VPL or VPM
• Where does the somatosensory cortex receive information from?

  From the thalamus
• What is the postcentral gyrus associated with?

  Somatosensory cortex
• What is the role of the anterior white commissure?

  Facilitates crossing of first-order neurons
• What is the function of the spinothalamic tract?

  Transmits pain, touch, and temperature sensations
• What is the significance of the somatotopic organization in the spinal cord?

  It arranges sensory information from body segments
• What is the role of the trigeminal nerve in mastication?

  Activates muscles of mastication
• What types of sensations are transmitted by the trigeminal nerve?

  Touch, pressure, temperature, and pain
• What is the function of the sensory pathways from the periphery to the cortex?

  Transmit specific sensory information to the brain
• What is the role of the somatosensory cortex?

  Process sensory information from the body
• What is the significance of the trigeminal ganglion?

  Contains cell bodies of sensory nerve fibers
• What is the function of the spinal trigeminal nucleus?

  Processes pain and temperature sensations