Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro > Gross Brain and Spinal Cord Memorization Info > Flashcards

Gross Brain and Spinal Cord Memorization Info Flashcards

1
Q

What is Brown-Sequard syndrome?

A
  • Results from a hemilesion of the spinal cord
    • Produces contralateral deficit in pain and temperature information
    • Ipsilateral deficit in vibration sense and proprioception
    • Spastic paralysis and hyperreflexia in ipsilateral body following an initial period of muscle weakness (UMN syndrome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is going on in bilateral anterior cord syndrome?

A

• Corticospinal tract is affected
○ Spastic paralysis and hyperreflexia in lower extremeties
• Anterolateral tract (AL) is affected
○ Decreased pinprick (pain) and temperature sensation in lower extremities
• You do not have problems with vibration and proprioception b/c you still have intact fasciculus gracilis and cuneatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the subcentral gyrus and where do you find it?

A
  • This is the U shaped connection between the pre-and-post-central gyri
    • Follow the central sulcus down untill it meets this gyrus, immediately cranial to the lateral sulcus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The pre-central gyrus is associated with what function?

A

• Primary motor cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The post-central gyrus is associated with what function?

A

• Primary somatosensory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is meant by “tract”

A

collection of CNS axons having a common site of origin and a common destinations
*example is corticospinal tract, originating in the cerebral cortex and ending in the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is meant by “bundle”

A

collection of axons that run together but do not necessarily have the same origin and destination
*example is medial forebrain bundle, which connects cells scattered within the cerebrum and brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is meant by “capsule”

A

collection of axons that connect the cerebrum with the brain stem
*example is internal capsule, connecting the brainstem and cerebral cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is meant by commissure?

A

any collection of axons that connect one side of the brain with the other side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is meant by “lemniscus”?

A

a tract that meanders through the brain like a ribbon

*example is medial lemniscus, which brings touch information from spinal cord through the brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the fornix in the brain do?

A

connects the hippocampus on each side with the hypothalamus

  • an example of a “bundle”
  • latin for “arch”
  • some of the axons in the fornix regulate memory storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where is the amygdala?

A

This is deep to the uncus, essentially the medioventral-most portion of the temporal lobe
*follow the tail of the hippocampus into the temporal lobe and go just a bit more medial and ventral and the amygdala is a spot/dot in there

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the amygdala important for?

A

This brain structure is important for regulating emotional states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The mammillary bodies in the brain are part of what structure and have what function?

A

The mammillary bodies are part of the hypothalamus.

  • they are nuclei that are found on the ventral surface of the brain, posterior to the hypothalamus and pituitary stalk
  • they are part of the circuity that stores memory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The superior colliculus receives what information?

A

direct input from the eyes and is involved in the control of eye movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The inferior colliculus receives what information?

A

important component of the auditory system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the cerebellar peduncles?

A

large bundles of axons that connect the cerebellum and the brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the three parts of the basal ganglia?

A

caudate nucleus, putamen and globus pallidus

  • if you have a coronal section that shows the third ventricle, caudate is on the infero-lateral border of the lateral ventricle
  • the globus pallidus will be the most infero-medial
  • the putamen will be separated by white matter from the globus pallidus and will be the more lateral
19
Q

What are the three major pathways that traverse from brain to spinal cord (or vice versa)?

A

• The principle efferent pathway is the corticospinal tract
○ Anterior/ventral corticospinal tract (minor)
○ Lateral corticospinal tract (major)
• Afferent (sesory)
○ Dorsal column/medial lemniscal system
§ Aka posterior column/medial lemniscal system
○ Anterolateral system
§ Aka spinothalamic tract

20
Q

What is the corona radiate?

A

• A collection of fibers in the cerebrum
• Funnel-shaped collection of white matter going from the cortex down to the brain stem
*part of internal capsule

21
Q

Where the crus cerebri enter the midbrain, what is the name of that structure?

A
  • The cerebral peduncle
    • The crus cerebri are the continuation of the internal capsule axons from the cortex to the spinal cord
    • Will make up the corticospinal tract
22
Q

Where do the alpha motor neurons reside?

A
  • Ventral grey matter of the spinal cord

* They send their axons out the ventral rootlets of the spinal cord where they will ultimately innervate muscle tissue

23
Q

Are upper and lower motor neurons always 1:1?

A
  • Nope. An UMN can innervate a pool of LMNs that do a similar task (synergistic action)
    • UMNs arising from the part of the motor cortex that corresponds to the somatotopy o fthe hand would be expected to innervate LMNs in the general “hand area” or C6,7,8,T1
24
Q

What are the important clinically testable spinal reflexes and what levels do they test?

A
  • Biceps - C5,6
    • Brachioradialis - C6
    • Triceps - C7
    • Patellar - L3,4
    • Achilles - S1
    • Plantar response - L5,S1
25
Q

What is Lower Motor Neuron syndrome?

A
  • Muscle weakness, lack in voluntary strength
    • Problem with reflexes, either hyporeflexic or areflexic
    • Low muscle tone, hypotonia or even flaccidity
26
Q

What is Upper Motor Neuron Syndrome?

A
  • Muscless innervated by the LMNs that the UMNs synapse with will be weak
    • Initial loss of reflex activity and muscle tone for days/weeks
    • Eventually the tone and reflex activity returns…but is exaggerated.
    • Hyperreflexia after an initial hyporeflexia and muscle weakness
27
Q

Where are the axons from the ventral/anterior corticospinal tract coming from?

A
  • They follow the internal capsule for most of the way
    • They do NOT cross over but descend ispsilaterally
    • Send a communication through the ventral white commisure and innervate contralateral alpha motor neurons that synergize the task of the ipsilateral ones
    • These are postural muscles
    • Located medially in the grey matter
    • More lateral in the grey matter are alpha motor neurons that are more for dexterity (lateral corticospinal tract)
28
Q

What might happen in a single hemisphere spinal cord damage because of the ventral white commissure?

A
  • You would get UMN syndrome affecting the contralateral muscles for dexterity, but the core muscles will remain innervated
    • the anterior corticospinal fibers from the intact hemisphere innervate these LMNs bilaterally
29
Q

What are the two principle pathways for transmission of somatosensory information to the CNS?

A

• ALS - anteriorlateral system
○ Pain and temperature
• Dorsal (or Posterior) Column/Medial Lemniscal system
○ DC/ML system
○ Information about discriminative touch, vibration sense, and proprioception

30
Q

Trace the sense of vibrative touch from the big toe.

A
  • Paccinian corpuscle tranduces vibration to an action potential
    • Axon for this nerve ending has it’s cell body in the L5 DRG
    • Found at junction between L5 and S1 vertebrae
    • Signal goes through ganglion into spinal canal along dorsal L5 rootlets in cauda equina and ascends to L5 segment of the true cord
    • Continues to ascend in fasciculus gracilis, dorsally within spinal cord
    • Synapse in the nucleus gracilis in the bottom of the brainstem
    • Crosses midline to ascend wthin brainstem as medial lemniscus
    • Medial lemniscus axon will synapse with the ventral posteriolateral nucleus (VPL) in the thalamus (thalamic nucleus is probably fine for now)
    • The thalamic nucleus will innervate the proper part of the primary somatosensory cortex
31
Q

What happens to the DC/ML system above the T6 dermatome?

A
  • Slight variation in the pathway
    • Axons still enter the spinal cord at their respective segments, but they ascend in an identifiable white matter column that is just lateral to fasciculus gracilis
    • It is called the fasciculus cuneatus, also in the dorsal column
    • Synapse with second order neuron in nucleus cuneatus (also lateral to the nucleus gracilis) in the brainstem
    • Second order neuron sends an axon across the midline to the in the medial lemniscus to the VPL third order neuron
    • The third order neuron will go to the cortex
32
Q

What ascending bundle does proprioceptive, fine touch and vibration below T6 run with? Below T6?

A
  • Above - fasciculus cuneatus, more lateral
    • Below - fasciculus gracilis, more medial
    • Both in the dorsal white matter
    • Both will go to nuclei in brainstem (either cuneatus or gracilis)
    • Both will have 3rd order neurons after VPL in thalamus
33
Q

Pain and temperature ascend using what system?

A
  • The anteriolateral system

* Different than the DC/ML tract

34
Q

Trace a painful stimululs (pin-prick) from the big toe to the cortex

A
  • Big toe recieves stimulus, carried through an axon who’s cell body isin the L5 dorsal root ganglion
    • Primary afferent will enter the L5 spinal segment through dorsal rootlet
    • It may ascend OR descend in a small band of white matter near the dorsal root entry zone called the Lissauer’s fasciculus
    • axon will terminate on a second order neuron located in a part of the dorsal grey matter of the spinal cord known as the substantia gelatinosa
    • Second order neuron projects axon across the midline via the ventral white commisure
    • Ascends in a column of white matter located in the anteriorlateral portion of the spinal cord
    • Axon ascends column until the third order neuron in the VPL (thalamus)
    • Third order neuron (thalamic nucleus) will innervate the somatosensory cortex
35
Q

What is another name for the ALS pathway?

A
  • ALS - anteriolateral system
    • Spinothalamic tract is another name for it because the signal is ascending the cord and synapsing with a third order nucleus in the VPL thalamus
36
Q

What is the substantia gelatinosa?

A

part of the dorsal grey matter in the spinal cord

  • carries the second order neurons in the pain and temperature sensation system
  • the anteriolateral system, or the spinothalamic tract
  • right after innervating the substantia gelatinosa there will be axons crossing the midline in the ventral white commissure before ascencion in the anteriorlateral portion of the spinal cord (white matter)
37
Q

What type of injury best highlights the different pathways of the DC/ML and ALS pathways?

A
  • A hemisection injury to the spinal cord
    • The result is dissociated sensory loss, in which one side of the body below the injury lacks pain and temperature sensation and the other lacks dorsal column sensation
    • The side lacking dorsal column sensation would experience UMN weakness
38
Q

What does the anterior horn of the spinal cord contain?

A

• Cell bodies of the lower motor neurons that innervate skeletal muscle in the limbs and torso

39
Q

What does the dorsal horn of the spinal cord contain?

A

• Neurons involved in processing information on pain and temperature

40
Q

What does the intermediate gray portion of the spinal cord contain?

A

• Interneurons as well as preganglionic sympathetic neurons in thoracic levels

41
Q

Vibration, discriminative touch and proprioception all follow what pathway?

A
  • The Dorsal column medial lemniscus pathway
    • DC/ML
    • Also PC/ML for posterior
42
Q

The DC/ML carries what type of information?

A

• Vibration, discriminative touch and proprioception

43
Q

Where are the cell bodies found for the axons traveling in the fasciculus gracilis?

A
  • Ipsilateral dorsal root ganglion
    • Vibration, discriminative touch and proprioception are carried through the fasciculus gracilis and cuneatus depending on the spinal level.
    • cross-over in this system happens in brain stem. nucleus gracilis or cuneatus is where the 2nd order neurons reside. they cross the midline to project to thalamus, the 3rd order neurons
    • Information ascends ipsilaterally until the brainstem
44
Q

What does the lissauer’s tract carry?

A
  • Axons from pain and temperature sensory DRG a few levels up or down from the section of cord you are looking at
    • These axons synapse on or near ipsilateral substantia gelatinosa before crossing in the ventral white commisure to be carried up the anteriorlateral portion of the white matter

Neuro (59 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions