Anatomy of the Basal Ganglia

Question 1

Whats 2 structures make up the Neostriatum? (striatum

Answer 1

caudate nucleus and Putamen

Question 2

what structures make up the Lentiform nucleus?

Answer 2

Putamen + globus pallidus

Question 3

What are the Structures (blue, purple and Green)

Answer 3

Blue- caudate nucleus

Green- putamen

Purple- Globus pallisu

Question 4

Labelled the colourred Structures

Answer 4

Blue Lateral ventricle

2- Caudate nucleus

Yello- internal capsule

Green- putamen

Purple- globus pallidus

Question 5

Label this

Answer 5

Question 6

What are we Looking at?

Answer 6

Substania Nigra in the midbrain

Question 7

what is the Green structure?

Answer 7

caudate nucleus

Question 8

What is the Green structure

Question 9

What is the this? (1,2,3,4)

Answer 9

1- caudate nuclues

2- putamen

3 globus pallidus externa

4- globus pallidus interna

Question 10

what is the structure in Green?

Answer 10

thalamus

Question 11

what are the 2 labelled Structures

Answer 11

Substania nigra (green)

subthalamic nuclues (other labelled ting)

Question 12

what is the nucleus accumbens?

Answer 12

head of caudate nucleus + putamen?

Question 13

what strcuture runs between caudtae nucleus and the putamen?

Answer 13

Internal capsule (white matter track)

where the corona radiata condense!

Question 14

what are the 2 labelled structures?

Answer 14

Globus pallidus interna and externa!

Question 15

what are the 3 structures labelled?

Answer 15

Question 16

what is the internal capsule?

Answer 16

cocnentration of white matter project fibres (convey impulses to and from cortex

(corona radiata condenses- motor and sensory fibres)

Question 17

Label the different parts of the internal capsule

Answer 17

Anteriro limb

genu (body)

porsteiror

Retrodenicula part

Question 18

What is the main blood supply to the basal ganlia/associated nucleis and internal capsule?

Answer 18

Lenticulostriate arteries

Branch of the middle Cerebral artery

Question 19

Describe the role of Motor Loops of the Basal ganglia

Answer 19

Question 20

which nuclei of the basal ganglia recieve input

Answer 20

Caudate nucleus , putamen

Question 21

which nuceli of the basal ganglia are ‘intrinsic (process information)

Answer 21

globus pallidus externus

subthalamic nucleus

substania nigra (pars compacta)

Question 22

what nulei of the BG are the ouput nuclei ?

Answer 22

Globus pallidus interna

substania nigra (pars reticulate)

Question 23

what are the roles of the direct and indirect pathway?

Answer 23

Question 24

Describe the Direct pathway

Answer 24

Cortex—–> striatun (caudate/putamen- Glutaminic acid)—–> this inhibits the glbus pallidus and substania nigra pars reticulata (output)—-> inhbiting there inhibitory action—–> thalmus increase acitivity (glutamic acid)—–> Cortex

Also have the dopaminergic Neurones of the SN pars compacta exert excitatory influence of the striatum

Question 25

describe the effect of Degeneration of the Dopaminergic neuroens of substania nigra pars compacta

Answer 25

Underactivity of the direct pathway (striatonigral)- movement decrease dopamine release Less activation of striatum so less inhbition of globus pallidus interna and substania nigra pars reticulata results in akinesia of Parkinsons disease

Question 26

describe the indirect pathway?

Answer 26

Cerebral cortex------\> caudate putamen ------\> inhbit the globus pallidus externus from inhibiting subthalmaic neurones increase in subthalamic neuronaal activity-----\> excite globus pallidus interna and SN reticulata -----\> increase inhbition of thalamus stop excitement of thalmus up to Cortex

Question 27

Describe how the Subthalmic nucleus can also recieve excitatory signal directly from the cortex? what does this do

Answer 27

Hyper Direct pathway (of the indirect pathway)

Question 28

Describe the neuropathology of Huntingtomns

Answer 28

attrition of the cells that project to the globus pallidus externus Lack of Inhbtiion from the striatum and therefore lakc of inhbtiion of subthamic nucleus Globus palliduse internus are underactive and unwanted movemetns occur