Exam 2- week 7 ppt 5 Cerebrum Basal Nuclei Connections Patho

Question 1

___ circuits have been described within the basal nuclei (origin and project)

Answer 1

3-5
~All of the pathways originating in various areas of cerebral cortex
~Cerebral cortex projects to the caudate nucleus, putamen, and nucleus acumbens

Question 2

circuits of the basal ganglion- main outputs

Answer 2

from globus pallidus (internus) & substantia nigra (pars reticulata)

Question 3

basal ganglion: efferent terminate in

Answer 3

the thalamus
~VA and VL- motor
~DM- cognitive

Question 4

basal ganglion: thalamus then projects

Answer 4

back to the cerebral cortex

Question 5

names of tracts for connections

Answer 5

~ansa lenticularis
~lenticular fasciculus
~nigro-thalamic

Question 6

Ansa lenticularis: location

Answer 6

~arises from the ventral surface of globus pallidus
~passes anteriorly through GP
~loops around the posterior limb of the internal capsule
~joins with lenticular fasciculus to form the ventral part of the thalamic fasciculus which ends in VA/VL thalamus

Question 7

Lenticular fasciculus: location

Answer 7

~from BN (globus pallidus) to the thalamus
~penetrates directly thru internal capsule
~is dorsal to ansa
~joins with ansa to form thalamic fasciculus which ends in VA/VL thalamus

Question 8

Nigro-thalamic: location

Answer 8

~from basal nuclei to thalamus
~arises from pars reticulata of substantia nigra
~runs dorsal to internal capsule to end in VA/VL thalamus

Question 9

Generally the connection through the BG are defined as

Answer 9

direct or indirect pathways

Question 10

direct pathways involves what pathway

Answer 10

Excitatory glutaminergic pathway from cortex to putamen

Question 11

direct pathway: details with putamen

Answer 11

~stimulates neurons in the Putamen which in turn produces GABAnergic inhibition of inhibitory GABA output from globus pallidus to thalamus.
~excites the Putamen to inhibits globus pallidus inhibition of thalamus.

Question 12

direct pathway: details with thalamus

Answer 12

Excited thalamic neurons which in turn excites motor cortex to produce movement

Question 13

disinhibition (what is it)

Answer 13

produced by a excitation of an inhibition of an inhibitory pathway to produce excitation

Question 14

disinhibition (and the putamen)

Answer 14

excited Putamen which inhibits the GP inhibition of thalamus to excite thalamus

Question 15

indirect pathway: excitatory pathway

Answer 15

Excitatory glutaminergic pathway from cortex to putamen

Question 16

indirect pathway: and putamen

Answer 16

Putamen GABAnergic inhibition produces inhibition of the inhibitory GABA output from globus pallidus externus to subthalamus

Question 17

indirect pathway: and subthalamus

Answer 17

excites globus pallidus internus

Question 18

indirect pathway: and GP internus

Answer 18

inhibits the thalamus, which can no longer excite the cortex
~the unexcited motor cortex will fail to produce movement

Question 19

Goal of direct pathway

Answer 19

increase movement

Question 20

Goal of indirect pathway

Answer 20

decrease movement

Question 21

changes in muscle tone can be seen with damage in different parts of

Answer 21

the basal nuclei

Question 22

types of changes in muscle tone

Answer 22

~hypertonia
~hypotonia
~combination of the two
~cogwheel rigidity

Question 23

hypertonia

Answer 23

rigidity

Question 24

hypotonia

Answer 24

falccidity

Question 25

Resting tremor

Answer 25

~Rhythmic, alternating movement of a body part
~Variable frequency and amplitude based upon disease process
~Parkinson’s disease has between 4-5 Hz with increasing amplitude with progression

Question 26

Chorea

Answer 26

~Brisk, large, complex movements
~Resemble fragments of purposeful movements
~May incorporate them into movement
~Huntington’s chorea or overdosing with Parkinson’s meds

Question 27

Athetosis

Answer 27

~another movement abnormality that is not uncommon in disorders such as cerebral palsy that can also be seen in certain basal ganglia disorders
~Slow, sinuous, writhing movements
~Continuous mobile spasm
~Most pronounced in fingers, hand and face

Question 28

Ballismus

Answer 28

~another involuntary movement associated with damage to the basal nuclei- specifically to the subthalamus
~Forceful, flinging movements
~Often rotatory and continuous
~Seen with subthalamic damage which releases movement

Question 29

Bradykinesia

Answer 29

~Lack of normal movement
~Reduced amplitude of movement
~Many of the symptoms of Parkinson’s disease are the result of this condition