Cerebellum Flashcards
The cerebellum is derived from the ________ of the rhombencephalon.
Alar plates or rhombic lips
More specifically, cerebellum is derived from the _________ of the rhombencephalon.
Metencephalon
Where does the cerebellum spans embryologically?
It spans between the pontine flexure and the rhombencephalic isthmus.
Where is cerebellum located?
Posterior cranial fossa, below the tentorium cerebelli
The Superior Cerebellar peduncle connects the _________ to the cerebellum.
Midbrain
The Middle Cerebellar peduncle connects the _________ to the cerebellum.
Pons
The Inferior Cerebellar peduncle connects the _________ to the cerebellum.
Medulla
How many lobes are there in cerebellum?
Anterior lobe
Posterior or Middle lobe
Flocculonodular lobe
The anterior and middle lobes are separated by ____________?
Primary fissure
The middle and flocculonodular lobes are separated by ____________?
Uvulonodular fissure
What does a deep horizontal fissure separates?
The superior and inferior surfaces of the cerebellum
The gray matter is divided into 3 layers which are?
Molecular or External layer; Purkinje or Middle layer; Granular or Internal layer, followed by white matter
What type of cells are found in the molecular layer?
Outer stellate cells
Inner basket cells
Neuroglial cells
What is the arrangement of cells in the molecular layer?
The cells are scattered in the numerous dentrites and axons of the granular cells that run parallel to long axis of folia
What neurons are found in purkinje layer?
Golgi type 1 neuron that are flask shaped and are arranged in a single layer.
The dendrites of the purkinje cells synapse with __________ and _____________.
Axons of the granular cells in the molecular layer
Axons of the climbing fibers in the molecular layer
The dendrites of the purkinje cells branch profusely and the subsequent branches of the dendrites are covered by _____________?
thick dendritic spines
The axons of the purkinje cells synapse with?
Cells in the intracerebellar nuclei
Cells in the vestibular nuclei
Colateral branches that synapse with stellate or basket cells in the molecular layer
What type of cells are there in the granular layer?
- Small cells with densely stained nuclei and scanty (small amount) of cytoplasm called granular cells
- Golgi Cells
- Neuroglia
The granular cells have (number) __________ dendrites that receive input from (mossy fibers/climbing fibers) ____________?
4-5 dendrites
Mossy fibers
The axons of the ____________ pass into the molecular layer and divide into T junction, they are called ___________?
granule cells
parallel fibers
The dendrites of the granular cells also receive input from _________ cells that are present in the granular layer.
Golgi cells
The dendrites of the golgi cells ramify in the _____________ layer?
Molecular layer
How many functional areas are there of cerebellum?
Vermis
Intermediate Zone
Lateral zone
What is vermis concerned with?
Movements of long axis of the body (neck, shoulders, thorax, abdomen and hips
What is the intermediate zone concerned with?
It controls the muscles of the distal parts of the limbs (hands and feet)
What is the lateral zone concerned with?
Planning of sequential movements of the entire body Conscious assessment of movement errors
How many intracerebellar nuclei are there?
Four. Dentate; Emboliform; Globose; Fastigial
What does the dentate nucleus look like?
It looks like a crumpled bag and is the largest nucleus
From where do the efferent nerve fibers of the dentate nucleus leave?
Superior Cerebellar Peduncle
What is the interposed nuclei made of?
Emboliform nucleus (medial to dentate nucleus) Globose nucleus (medial to emboliform nucleus)
The fastigial nucleus is situated in the (vermis/ intermediate zone/ lateral zone) _________?
Vermis (near the midline) (close to the roof of fourth ventricle)
The fastigial nucleus is larger than ________ nucleus.
Globose nucleus
The axons of the nuclei leave the cerebellum through ____________?
Superior and Inferior cerebellar peduncles
What type of neurons do the intracerebellar nuclei have?
Large multipolar neurons with simple branched dendrites
The white matter of the cerebellum looks like a tree so it is called _________?
Arbor vitae
Vermis has (small/large) ________ amount of white matter while the cerebellar hemispheres have (small/large) _________ amount.
Small amount in the vermis
Large amount in the cerebellar hemispheres
How many type of fibers are there in the white matter of the cerebellum?
Three. Intrinsic; Afferent; Efferent
The afferent fibers of the cerebellum enter it through the __________ and ____________ peduncles.
Middle and Inferior peduncles
What are the efferent fibers of the cerebellum?
Axons of the purkinje cells that may synapse on the deep nuclei, some fibers bypass the nuclei; they belong to the flocculonodular lobe and parts of vermis.
Fibers from Dentate, Emboliform, and Globose nuclei leave the cerebellum through __________ peduncle.
Superior Cerebellar peduncle
Fibers from the fastigial nuclei leave the cerebellum through the _________ peduncle.
Inferior Cerebellar peduncle
What is the function of folia in cerebellum?
They increase the surface area
Where do the mossy fibers arrise from?
Vestibular nuclei, pontine nuclei, etc
Where do the climbing fibers arrise from?
Inferior olivary nucleus
Where do the climbing fibers synapse?
They synapse with the dendrites of the purkinje cells in the molecular layer. One climbing fiber synapse with 1-10 purkinje cells while one purkinje cell synapse with one climbing fibers
Where do the mossy fibers synapse?
They may synapse at the intracerebellar nuclei or with the granular cells in the granular layer
What type of effect does the purkinje cells have on the nucleus?
Purkinjie cells sends axons to the deep nuclei but unlike mossy fibers, they have an inhibitory effect