4: Anatomy - Basal ganglia and cerebellum Flashcards
What are the three lobes of the cerebellum?
Anterior lobe
Posterior lobe
Flocculonodular lobe
What separates the anterior lobe of the cerebellum from the posterior lobe (but in reality can’t be seen)?
Primary fissure
In which cranial fossa is the cerebellum found?
Which sheet of dura sits on top of it?
Posterior cranial fossa
Tentorium cerebelli
Which structures anchor the cerebellum to the midbrain?
Peduncles
(superior, middle and inferior)
Which structure runs down the middle of the cerebellum and is associated with posture and movement?
Vermis (superior and inferior)
What is the name of the big core of white matter found within the cerebellum?
Arbor vitae
The cerebellar cortex has three ___ of cells.
layers
What are the three layers of cerebellar cells?
Molecular layer on the outside
Purkinje layer in the middle
Granule layer on the inside
Arrange into the correct order from inside to outside:
Granular cell layer
Molecular layer
Purkinje cell layer
From inside to outside:
granular cell layer
Purkinje cell layer
molecular layer
From which layers of the cerebellum are:
a) afferent signals received
b) motor signals sent?
a) Granular cell layer
b) Purkinje cell layer
What is the function of the cerebellum?
Receives sensory signals (from everywhere including the brain) and relays them to the THALAMUS
=> COORDINATION OF BODY MOVEMENTS
see cerebellum think coordination
The cerebellum regulates ___ movement.
voluntary
What is the function of the thalamus?
Receives SENSORY INFORMATION from the ascending pathways and relays them to the cerebral cortex
The cerebellum is made up of two ___.
hemispheres
Each cerebral hemisphere controls the (ipsilateral / contralateral) side of the body.
ipsilateral
fibres DON’T cross over
What happens if you have midline cerebellar lesion?
Loss of postural control
Think of it as affecting your midline postural muscles like (back, gluteals etc.)
What happens if you have a unilateral cerebellar lesion?
Loss of coordination in the limbs on that side
What happens if you have a bilateral cerebellar lesion?
Loss of coordination of limbs on both sides
Dysarthria - slurred speech
Cerebellar ataxia - staggering, wide-based gait
What happens if you have a
a) bilateral
b) midline
c) unilateral
cerebellar lesion?
a) Loss of coordination in limbs on both sides, slurred speech
b) Intact limb coordination, loss of postural control
c) Loss of coordination in limbs on one side
What causes short-term bilateral cerebellar dysfunction?
What are the symptoms?
Alcohol excess
Loss of coordination in limbs on both sides, slurred speech
What is a ganglion?
Mass of neuron bodies found in the PNS
Why is basal ganglion a misnomer?
Basal ganglia are found at the base of the cerebral hemispheres, which is in the CNS
So should really be called ‘basal nuclei’
What is the function of the basal ganglia?
Act on thalamus to:
Regulate voluntary movement
Inhibit unwanted movements
What are the names of the five basal ganglia?
Caudate nucleus
Putamen
Globus pallidus
Substantia nigra
Subthalamic nucleus
The basal ganglia are found in the ___ of cerebral hemispheres.
bases
i.e looking down from above
On this diagram, label three basal ganglia.
Where is the substantia nigra found?
Cerebellum
Where is the subthalamic nucleus found?
Under the thalamus
What names are given to the following groups of basal ganglia?
1) Putamen + Caudate nucleus
2) Putamen + Globus pallidus
3) Putamen + Caudate nucleus + Globus pallidus
1) Striatum
2) Lenticular nucleus
3) Corpus striatum
What colour is the substantia nigra?
Black
Which basal ganglion degenerates in Parkinson’s disease?
Substantia nigra
Which disease occurs if the substantia nigra degenerates?
Parkinson’s disease
The basal ganglia act on the thalamus to amplify or inhibit conscious movements, posture etc.
How do they a) enhance and b) inhibit desired and unwanted movements?
a) Direct pathway
b) Indirect pathway
Which two neurological diseases are associated with degeneration of the basal ganglia?
Parkinson’s disease
Huntington’s disease
Is Huntington’s disease autosomal dominant or recessive?
Autosomal dominant
