Exam 1 Flashcards
The fasciculus gracilis is ____ to the fasciculus cuneatus in the spinal cord
Medial
The fasciculus ____ carries touch and conscious proprioception information from the lower body and limbs (sacrum, lumber, T6-T12) to the brainstem
Gracilis
The fasciculus ____ carries touch and conscious proprioception information from the upper body and limbs (T6 and above) to the brainstem
Cuneatus
Name the two conscious sensory tracts
- Dorsal white column/medial lemniscus pathway
2. Spinothalamic tract
The dorsal white column/medial lemniscus pathway carries what type of information?
Discriminating touch and conscious proprioception
The spinothalamic tract carries what type of information from the body wall and limbs?
Pain, temperature, light touch
High threshold stimuli (mechanical, thermal, chemical) can be associated with what conscious sensory tract?
Spinothalamic tract (nociceptive - tissue damaging stimuli)
Low threshold stimuli can be associated with what conscious sensory tract?
Dorsal white column/medial lemniscus pathway (non-tissue damaging stimuli)
The decussation of the pyramids (conscious motor tracts) is just ____(caudal, rostral) to the decussation of the medial lemniscus-in the caudal closed medulla
Caudal
Before the decussation of the pyramids, the conscious motor tracts are known as:
Corticospinal tracts (pyramids)
The Anterior Corticospinal tract innervates the ____ muscles bilaterally
Axial
The Lateral Corticospinal Tract innervates the ____ muscles contralaterally
Appendicular
Conscious input to the cranial nerves (except I, II and VIII) is known as the ____ tracts
Corticobulbar
Which cranial nerve innervations are primarily CONTRALATERAL?
- Lower face of VII
- CN XI
- CN XII
Generalizing, the axons of low threshold stimuli (discriminating touch/proprioception) tend to be _____ (myelinated/unmyelinated) and the sensory cell bodies tend to be ____ (small/large)
Myelinated, large
The primary afferent axons of the ____ pathway tend to go up or down several segments in the cord before synapsing on the 2nd order neurons
Pain/temperature (nociceptive, thermal stimuli), or spinothalamic tract
The conscious sensory tracts end where?
In the cortex of the parietal lobe
Which conscious sensory tract enters the MEDIAL part of the dorsal root, and which one enters the LATERAL part of the dorsal root?
Medial- DWC/ML Pathway
Lateral - Spinothalamic Tract
The corticospinal tracts synapse in lamina ___ in the spinal cord before the GSEs leave to innervate muscles
IX
The corticobulbar tracts synapse on what cranial nerves in the MIDBRAIN?
III and IV
The corticobulbar tracts synapse on what cranial nerves in the PONS?
V, VI, VII
The corticobulbar tracts synapse on what cranial nerves in the MEDULLA?
IX, X, XII
The roof or “tectum” of the brainstem is ____(ventral/dorsal) to the cerebral aqueduct/central canal?
Dorsal
The floor or “tegmentum” of the brainstem is located where?
In the middle of the brainstem. Between the tectum (roof)-anterior to cerebral aqueduct/central canal, and the basilar portion (ventral-motor)
The basal portion of the brainstem is where?
Most ventral portion (mainly motor), anterior to the tegmentum (floor)
Where do the conscious motor tracts come from (originate)?
Pre-central gyrus of the frontal lobe cortex
