Neuroanatomy 06: Corticospinal Tract And Other Motor Pathways

Front 1

Primary motor cortex is Broadman's Area # ...

Back 1

4

Front 2

Primary motor cortex is found in the (pre-central or post-central) gyrus?

Back 2

pre-central gyrus (anterior to central gyrus)

Front 3

Primary sensory cortex is Broadman's area #...

Back 3

3, 1, 2

Front 4

Primary sensory cortex is found in the (pre-central or post-central) gyrus?

Back 4

post-central gyrus (posterior to central gyrus)

Front 5

A lesion in the association cortex would lead to what type of deficit?

Back 5

apraxia. since it is not in the motor or sensory cortex, there would be no sensory or motor deficit, but there would be a problem processing the information. association cortex is for higher order analysis

Front 6

The lateral portions of the "homunculus" control what region of the body?

Back 6

face

Front 7

In a spinal cord cross-section, where is the gray matter located? (Inner portion or outer portion)

Back 7

grey matter is inside, surounded by white matter axons arranged in columns

Front 8

The corticospinal tract is found in the gray matter or white matter?

Back 8

white matter (outer portion of spinal cord) since they are myelinated axons

Front 9

The cervical enlargement gives rise to ...

Back 9

brachial plexus

Front 10

A patient has weakness in their leg. Is there a lesion most likely on the lateral portions of the brain or the interhemispheric fissure?

Back 10

interhemispheric fissure. according to the motor homunculus, leg is controlled by the area nearest to the midline (interhemispheric fissure). the lateral areas control face and arms

Front 11

All spinal levels have dorsal and ventral horns. Lateral horns are found only in which spinal levels?

Back 11

T1-L2 for the sympathetic preganglionic cell bodies

Front 12

Where is the anterior spinal artery found?

Back 12

running up/down the anterior, midline of the spinal cord

Front 13

Where are the posterior spinal arteries found?

Back 13

running up/down the posterior, lateral sides of the spinal cord

Front 14

From the spinal-arterial plexus surrounding the cord, the branches that reach the cord itself are called ...

Back 14

radicular arteries

Front 15

Where is the Great Radicular artery of Adamkiewicz found?

Back 15

major artery at left T9-T12

Front 16

What portion of the spinal cord receives the least perfusion?

Back 16

T4-T8 is called the vulnerable zone between lumbar and vertebral artery supply

Front 17

The cerebellum and basal ganglia relay information to the cortex via ...

Back 17

thalamus

Front 18

2 main lateral motor tracts

Back 18

lateral corticospinal and rubrospinal

Front 19

4 main medial motor tracts

Back 19

anterior corticospinal, vestibulospinal, reticulospina, tectospinal

Front 20

According to the homunculus, lateral motor tracts are more likely to control what regions of the body?

Back 20

arms, extremities. medial areas will control the main muscles of head, posture, axial skeleton etc.

Front 21

Loss of the right anterior corticospinal tract will cause motor deficit on which side?

Back 21

neither. the left and right medial tracts (including the anterior cotrticospinal tract) give off neurons to both sides. in this situation, the left anterior corticospinal tract will still be giving innervation. only bilateral lesions of the medial tracts lead to motor loss

Front 22

What are Betz cells?

Back 22

large pyramidal cells of the lateral corticospinal tract

Front 23

The corticospinal tract lies in which limb of the internal capsule?

Back 23

posterior limb

Front 24

The posterior limb of the internal capsule separates which two structures?

Back 24

globus pallidus and thalamus

Front 25

The anterior limb of the internal capsule separates which two structures?

Back 25

head of caudate and globus pallidus/putamen

Front 26

What are corticobulbar fibers?

Back 26

they are the fibers of the corticospinal tract that go to the brainstem from the cortex to innervate the face

Front 27

The internal capsule and corticospinal tract cross through which part of the cerebral peduncles?

Back 27

basis pedunculis (ventral side)

Front 28

Where do the corticospinal tract fibers cross?

Back 28

medullary pyramids at the pyramidal decussation

Front 29

A lesion in the right internal capsule would cause motor deficits on which side of the body?

Back 29

since the internal capsule is above the medullary pyramids, the tract hasn't crossed yet. right side lesion = left side paralysis

Front 30

After the white matter neurons run down the lateral corticospinal tract, where do they synapse to motor neurons?

Back 30

anterior horns gray matter

Front 31

Which preganglionic neurons are longer? Sympathetics or Parasympathetics?

Back 31

Parasympathetic preganglionics have to go all the way to the effector organ to synapse on postganglionic neurons. the sympathetics only have to enter the paravertebral column white rami

Front 32

What are corticobulbar fibers?

Back 32

they are the fibers of the corticospinal tract that go to the brainstem from the cortex to innervate the face

Front 33

The internal capsule and corticospinal tract cross through which part of the cerebral peduncles?

Back 33

basis pedunculis (ventral side)

Front 34

Where do the corticospinal tract fibers cross?

Back 34

medullary pyramids at the pyramidal decussation

Front 35

A lesion in the right internal capsule would cause motor deficits on which side of the body?

Back 35

since the internal capsule is above the medullary pyramids, the tract hasn't crossed yet. right side lesion = left side paralysis

Front 36

After the white matter neurons run down the lateral corticospinal tract, where do they synapse to motor neurons?

Back 36

anterior horns gray matter

Front 37

Which preganglionic neurons are longer? Sympathetics or Parasympathetics?

Back 37

Parasympathetic preganglionics have to go all the way to the effector organ to synapse on postganglionic neurons. the sympathetics only have to enter the paravertebral column white rami

Front 38

Where are sympathetic preganglionic cell bodies located?

Back 38

IML of T1-L2

Front 39

Where are parasympathetic preganglionic cell bodies located?

Back 39

cranial nerve nuclei and lateral gray matter of S2-S4

Front 40

All preganglionics autonomic neurons release which neurotransmitter?

Back 40

Ach

Front 41

All sympathetic postganglionic neurons use which neurotransmitter? Which sympathetic organ is the exception?

Back 41

epinephrine/norepinephrine. However, sweat glands are innervated by sympathetic postganglionic neurons that release Ach

Front 42

2 type of Ach receptors

Back 42

nicotinic and muscarinic

Front 43

Cell bodies of lower motor neurons are located where?

Back 43

lateral gray matter of spinal cord

Front 44

Cell bodies of upper motor neurons are located where?

Back 44

cerebral cortex gray matter

Front 45

Fasciculations and weakness are signs of (upper or lower) motor neuron lesion?

Back 45

lower

Front 46

Spasticity and weakness are signs of (upper or lower) motor neuron lesion?

Back 46

upper

Front 47

Positive Babinski sign indicates an (upper or lower) motor neuron lesion?

Back 47

upper

Front 48

Atrophy would be most likely with an (upper or lower) motor neuron lesion?

Back 48

lower. leads to less use/innervation

Front 49

What is hemi-paresis?

Back 49

unilateral weakness

Front 50

What is a palsy?

Back 50

weakness or paralysis

Front 51

What is hemiplegia?

Back 51

unilateral paralysis of whole side of body

Front 52

What is paraplegia?

Back 52

bilateral leg paralysis