Cerebral Cortex- Sensory Motor Pathway

Question 1

Ascending- Spinocerebellar Path

Answer 1

1st order: sensory receptor–> dorsal gray horn
2nd order: ascends up spinal cord in both dorsal and ventral tracts to cerebellum
-ipsilateral
-proprioceptions
-coordinates body movements

Question 2

Ascending- Dorsal Column Path

Answer 2

1st: sensory receptor–> 2 different dorsal white tracts (medial faciculus gracilis & lateral fasciulus cuneatus)–> nucleus gracilis & nucleus cuneatus –> medulla
2nd: decussates–>medial leminscus tract –> thalamus
3rd: thalamus –> primary somatosensory –> postcentral gyrus
- contralateral
- precisely localized sensations (discriminative)

Question 3

Ascending- Spinothalamic Pathway

Answer 3

1st: sensory receptor–> dorsal gray horn
2nd: decussates–> lateral + ventral funiculi –> postcentral gyrus–> unpleasant sensation

contralateral
unpleasant- pain, pressure, temperature
non-discriminative touch

Question 4

Descending

Answer 4

most motor pathways, decussate at some point, chain of neurons, somatotopy, paired

Question 5

Descending- Pyramidal Path

Answer 5

descend through internal capsule from primary motor cortex.
lateral tracts decussate in the medulla
ventral in the spinal cord
axons extend to spinal gray matter and synapse with interneurons or somatic motor neurons. These then synapse with the peripheral motor receptors
precise voluntary movement.

Question 6

Lou Gehrigs (Amyotropic lateral sclerosis)

Answer 6

degeneration of the pyramidal tracts– harden into scar tissue
wasting, atrophy of muscles
fatal

Question 7

Descending- other tracts

Answer 7

reticulospinal- RAS to median nuclear groups of pons and medulla
tectospinal- from superior colliculus of midbrain
vestibulospinal- vestibular nuclei in medulla

Question 8

Descending- Rubrospinal Tract

Answer 8

red nucleus–> decussation (midbrain)–> spinal gray matter–> interneuron or somatic–> peripheral
subconscious movements e.g. posture

Question 9

paralysis

Answer 9

no motor function

Question 10

paraplegia

Answer 10

spinal cord injury to T1-L2, no lower limb funtion

Question 11

paresthasia

Answer 11

no sensation

Question 12

quadripeligia

Answer 12

spinal cord injury in cervical region causing no limbs to work at all

Question 13

Thrombotic stroke

Answer 13

due to a clot

Question 14

hemmorrhagic stroke

Answer 14

due to bleeding in brain