Just everything... Flashcards
Holy eft…just get us through this exam! (149 cards)
List somatosensory sensations carried EXCLUSIVELY by the DC/ML
Vibration (fine touch), proprioception, texture
List somatosensory sensations carried EXCLUSIVELY by the ALS
Temperature, slow pain, visceral pain
List somatosensory sensations carried EXCLUSIVELY by both the DC/ML and ALS
Pressure touch, hair associated touch, fast pain
Special skin receptor sensing texture (discriminatory touch)
Meissner corpuscles
Special skin receptor sensing vibration
Deep = Pacinian corpuscles. Superficial = Meissner corpuscles
Special skin receptor sensing pressure
Deep = Pacinian corpuscles. Superficial = Merkel’s disks
Where are the cell bodies in the DC/ML pathway?
DRG - Caudal Medulla (Gracile and Cuneate Nuclei) - Ventral Posterior Lateral Nucleus of the Thalamus - Precentral Gyrus
Where do the tracts of the DC/ML pathway terminate?
Pre central gyrus of the cerebral cortex
Do the fibers of the DC/ML pathway decussate? If so, where?
Yes, in the caudal medulla’s pyramidal decussation
Do any branches come off the DC/ML pathway? If so, what function do they serve?
Yes, but they are going to the cerebellum and serve to provide proprioceptive feedback of what the body is doing
Where do the corticobulbar fibers decussate?
In the middle Pons
What fibers make up the bulk of the INCOMING middle cerebellar peduncle fibers?
The corticobulbar fibers from the basilar pontine nuclei
Once in the cerebellum, what happens to the corticobulbar fibers?
They split with some going to the deep cerebellar nuclei and others going to the cerebellar cortex
Proprioceptive loss if the dorsal column at C4 was destroyed?
Loss of proprioception on the same side
Proprioceptive loss if the DRG at C4 was destroyed?
Loss of proprioception on the same side
Proprioceptive loss if the ALS at C4 was destroyed?
No loss of proprioception. ALS is NOT proprioception
Proprioceptive loss if the lateral portions of the primary somatosensory cortex was destroyed?
Loss of proprioception of the face and upper extremities on the opposite side
Proprioceptive loss if the medial portions of the primary somatosensory cortex was destroyed?
Lower limb proprioceptive loss on the opposite side
What sensation is unique in that it does not reach the cerebral cortex by going through relay nuclei?
Olfaction
When does sensation enter conscious awareness?
When the signal reaches the cerebral cortex
T/F DC/ML neurons are larger and more heavily myelinated than ALS neurons
TRUE
Where does DC/ML pathway information decussate?
In the caudal medulla
Where does the ALS pathway decussate?
In the spinal cord
T/F Many more ALS axons reach the cerebrum
FALSE. Many more DC/ML fibers do…which contributes to such fine perception and localization of sensation