Mod 3 Brain White Matter Pathways Flashcards Preview

Neuro exam 1 mod 1-7 > Mod 3 Brain White Matter Pathways > Flashcards

Flashcards in Mod 3 Brain White Matter Pathways Deck (58)
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1
Q

What are the white matter pathways?

A
  1. Projection
  2. Association
  3. Commissural
2
Q

The projection pathways are ____ pathways that run between ___ and ___

A

Vertical
Cortex
Lower levels

3
Q

___ connect areas within hemispheres

A

Association

4
Q

___ connect areas between hemisphere

A

Commissural

5
Q

pathways connection and interconnection functions include

A
  1. Keep the brain informed of what’s going on within and outside the CNS
  2. Mediate info transfer between modalities
  3. Coordinate activities between hemispheres
6
Q

Characteristics of projection pathways

A
  1. Connect the cortex with lower levels
  2. Travel vertically to connect cortex with brain structures and spinal cord
  3. Include both efferent (outgoing/motor) and afferent (incoming/sensory) pathways
7
Q

What is the most prominent and important motor projection system

A

Pyramidal tract

8
Q

True or false: the pyramidal tract is comprised of the corticospinal pathway

A

False: both corticospinal and corticobulbar pathway

9
Q

What is the pyramidal tract responsible for

A

Initiation and control of skilled voluntary movements

10
Q

Where do the fibers in the pyramidal tract originate from?

A

Areas 4, 6 in the frontal lobe

Area 3-1-2 in the parietal lobe

11
Q

True or false:

The motor neurons that make up the pyramidal tract (both corticospinal and corticobulbar) are lower motor neurons

A

False: upper motor neurons

12
Q

_____ are peripheral nerves

A

Lower motor neurons

13
Q

Lower motor neurons innervate the ______ muscles

A

Voluntary/skeletal muscles

14
Q

LMN is also known as

A

Final common path

15
Q

Upper motor neurons are _____ motor neurons with the _____ that exert influences either directly or indirectly on the LMNs

A

Descending

CNS

16
Q

Sensory data is relayed to the thalamus then to the cortex via the ____ pathways

A

Thalamocortical pathway

17
Q

The motor projects extend from the ____ to the ____ and ____

A

Cortex

Brainstem and spinal cord

18
Q

Motor projects descend downward to the brainstem via the _____, ______ and _____

A

Corona radiata
Internal capsule
Cerebral peducles (crus cerebri)

19
Q

___ is a fan shaped radiating projection system located between the cerebral cortex above and the internal capsule below

A

Corona radiata

20
Q

The motor pathways extend downward from the ____ areas through the _____ and converge before enter the the ____

A

Cortical
Corona radiata
Internal capsule

21
Q

True or false

The corona radiata is comprised of only motor pathways

A

False
Comprised of both motor and sensory pathways
- incoming sensory pathways extend upward from the internal capsule to the cortex.

22
Q

What is the internal capsule

A

A massive bundle of nerve fibers found between the thalamus, caudate nucleus and lenticular nucleus

23
Q

Most signal, both efferent and afferent, between the cerebral cortex and the lower brainstem, and spinal cord are transmitted between ___

A

Internal capsule

24
Q

The internal capsule is divided into what parts

A
Anterior limb (between the caudate and lenticular nucleus)
Posterior limb (between the lenticular nucleus and thalamus)
Genu (between the anterior and posterior limb)
25
Q

What does the anterior limb carry

A

Motor data

Affective and emotional data

26
Q

The anterior limb carries motor data via the

A
Frontopontine pathway (frontal lobe/cortex to the pons)
Corticostriate pathway (cortex to BG/striatum)
27
Q

The anterior limb carries affective and emotional data via

A
Reciprocal connection pathways 
Includes:
Between the prefrontal cortex and thalamus
Between the cingulate gyrus and thalamus
Between the septal area and hypothalamus
28
Q

What passes through the Genu of the internal capsule

A

The corticobulbar pathway = motor commands for speech

The corticoreticular pathway = arousal and alertness

29
Q

The posterior limb contain both ___ and ___ pathways

A

Moto and sensory

30
Q

Posterior limb: motor has what kind of pathway

A

Corticospinal

31
Q

What does the motor posterior limb innervate

A

Limb and trunk muscles

32
Q

The posterior limb sensory carry general and sensory data to

A
  1. General to Somatosensory cortex (3-1-2)
  2. Auditory to Heschl’s gyrus (41 and 42)
  3. Visual to striate cortex (17)
33
Q

The association pathways provide ____ communication between cortical areas

A

Bidirectional

34
Q

In the association pathways, there are ___ and ____ groups

A

Long and short

35
Q

What areas do not communicate directly with each other?

A

Primary areas

36
Q

How do primary areas communicate with each other

A

Via the association areas

37
Q

Arucate fasciculus is also called

A

Superior longitudinal (located lateral to insula)

38
Q

What does the arcuate fasciculus connect?

A

Interconnects the frontal, parietal, occipital and temporal cortices
Connects Wernicke’s and Broca’s areas

39
Q

What is conduction aphasia

A

A disconnection syndrome between Wernicke’s and Broca’s aphasia

40
Q

Where is the lesion that would cause conduction aphasia

A

Arcuate fasciculus lesion

41
Q

What is the result of conduction aphasia

A

Good comprehension, reduced and impaired speech output

42
Q

Where is the inferior occipital fasciculus located

A

Crosses beneath the Sylvia’s fissure and insula

43
Q

What does the inferior occipital fasciculus connect?

A

The frontal lobe to occipital lobe and the inferior temporal lobes she

44
Q

Where is the uncinate fasciculus located

A

Parallel to the inferior longitudinal fasciculus

45
Q

The uncinate fasciculus connects

A

Orbital frontal with anterior temporal lobe cortex

46
Q

The cingulum connects

A

The frontal, parietal, temporal area medially

Interconnects these areas with the limbic area

47
Q

If there is a lesion on the cingulum what is impaired?

A

emotion and affective behavior

48
Q

Commissural pathways

A

Run horizontally to connect hemispheres

Connect similar structures on each side

49
Q

What are the main commissures

A

Corpus callosum
Anterior commissure
Posterior commissure

50
Q

What is the largest commissural bundle

A

The corpus callosum

Contain 300-400 million fibers

51
Q

What are the parts of the corpus callosum

A
Rostrum (interconnects the frontal areas)
Genu 
Body (interconnects parietal areas)
Splenium (interconnects occipital areas)
52
Q

The anterior commissure interconnects the ___ lobe

A

Temporal lobe

53
Q

The posterior commissure interconnects _____ _____ _____

A

Midbrain reflex centers

54
Q

Lesions to association and commissural fibers lead to

A

Disconnections between cortical areas = disconnection syndrome

55
Q

What is apraxia

A

Motor programming disorders that affect limb movement (limb apraxia), speech movements (apraxia of speech) and oral non speech movements (oral apraxia/swallowing apraxia)

56
Q

What is Alexias

A

Acquired reading disorder

57
Q

What is anomia

A

Unable to recall the names of everyday objects

58
Q

Disconnection syndromes caused by lesions of association and commissural fibers can cause:

A

Apraxias
Anomia
Alexias