Cerebellum Flashcards
•Function of The cerebellum:
.
.
•The cerebellum:
•Coordinates gait
•Maintains posture,
•Controls muscle tone and voluntary muscle activity
.
•Is the cerebellum able to initiate muscle contraction
No
The cerebellum is neuron-rich, containing —% of the brain’s neurons organized in a dense cellular layer, and its surface area when unfolded is nearly —% of the surface area of the cerebrum.
The cerebellum is neuron-rich, containing 80% of the brain’s neurons organized in a dense cellular layer, and its surface area when unfolded is nearly 75% of the surface area of the cerebrum.
Fore brain is the largest part of the brain, most of which is ————. Other structures found in the forebrain include the ———
Mid brain (mesencephalon) connects the ——- and the ——— and functions include; ———-
• Hind brain links the forebrain and mid brain to the ———. It is made up of the ——-,——-which maintains balance and equilibrium, movement coordination and the conduction of sensory information) and ———- (medulla oblongata which has autonomic functions in controlling breathing, heart rate and digestion)
Fore brain is the largest part of the brain, most of which is cerebrum hemisphere ( telencephalon). Other structures found in the forebrain include the thalamus, the hypothalamus and the limbic system (diencephalon )
Mid brain (mesencephalon) connects the forebrain and the hind brain and functions include; auditory and visual responses as well as motor function
• Hind brain links the forebrain and mid brain to the spinal cord. It is made up of the metencephalon (pon and cerebellum which maintains balance and equilibrium, movement coordination and the conduction of sensory information) and myelencephalon (medulla oblongata which has autonomic functions in controlling breathing, heart rate and digestion)
In Latin, the word cerebellum means ———’.
In Latin, the word cerebellum means little brain’.
the cerebellum accounts for approximately —% of the brain’s volume,
the cerebellum accounts for approximately 10% of the brain’s volume,
The cerebellum is located in the ——— cranial fossa
It is located posterio-superiorly to the —— tucked underneath the cerebral hemispheres underlying its —— and ——- lobes
The cerebellum is separated from the pons and medulla by the ——— and the ———.
The cerebellum is located in the posterior cranial fossa
It is located posterio-superiorly to the brain stem tucked underneath the cerebral hemispheres underlying its occipital and temporal lobes
The cerebellum is separated from the pons and medulla by the cerebral aqueduct of Sylvius and the fourth ventricle.
Cerebellar cortex
The cerebellar cortex is the superficial layer of — matter consisting mainly of nerve —— and ——.
Its cortical surface appears as finely spaced ——- grooves, in striking contrast to the broad irregular convolutions of the cerebral cortex.
Within the folds are large number of thin neurons regularly arranged, this accommodating about —% of the total number of neurons in the brain even when the cerebellum is 10% of the brain’s volume
Cerebellar cortex
The cerebellar cortex is the superficial layer of gray matter consisting mainly of nerve cell bodies and dendrites.
Its cortical surface appears as finely spaced parallel grooves, in striking contrast to the broad irregular convolutions of the cerebral cortex.
Within the folds are large number of thin neurons regularly arranged, this accommodating about 50% of the total number of neurons in the brain even when the cerebellum is 10% of the brain’s volume
Microscopically within the thin layer of cerebellar cortex is;
Microscopically within the thin layer of cerebellar cortex is;
• Molecular laver (external)
• Purkinje layer (middle)
• Granular layer (internal)
Cerebellar medullary core
• Underneath the gray matter of the cortex lies white matter called the ——-
• Underneath the gray matter of the cortex lies white matter called the arbor
vitae
• Made up largely of myelinated nerve fibers running to and from the cortex.
Arbor vitae
•In latin “ ———” it is the white matter of the white matter of cerebellum.
•It is so called because of the tree like
appearance
•It brings ——- and —— sensation to and from cerebellum.
Arbor vitae
•In latin “ tree of life” it is the white matter of the white matter of cerebellum.
•It is so called because of the tree like
appearance
•It brings sensory and motor sensation to and from cerebellum.
Deep cerebellar nuclei
The cerebellum has deep cerebellar which are:
Deep cerebellar nuclei
The cerebellum has deep cerebellar nuclei
(Dentate nucleus;
Emboliform and
Globose nuclei (interposed nucleus);
Fastigial nuclei;
embedded within the center of the white matter.
——— and ——— nuclei (interposed nucleus);
Emboliform and
Globose nuclei (interposed nucleus);
M
Cerebellar hemispheres
The cerebellum is divided into how many cerebellar hemispheres seperated by a narrow midline zone called——-
located along the mid-sagittal plane of the cerebellum.
The cerebellum is divided into two cerebellar hemispheres seperated by a narrow midline zone (vermis)
located along the mid-sagittal plane of the cerebellum.
Lobes
1. ——— lobe
(above the ——— fissure)
2. ——— lobe (below the ——- fissure)
3. ——— lobe (below the posterior fissure).
These lobes divide the cerebellum from ——— to ——— (top to bottom).
Lobes
Anterior lobe
(above the primary fissure)
Posterior lobe (below the primary fissure)
Flocculonodular lobe/ vestibulocerebellum / archicerebellum (below the posterior fissure).
These lobes divide the cerebellum from rostral to caudal (top to bottom).
Each lobe is further subdivided into ——.
Lobules
Two major fissures running mediolaterally divide the cerebellar cortex into three primary lobes
1. —— fissure separates the corpus cerebelli into a —— lobe and an —— lobe
2. ——— fissure separates the ——— lobe from the ——- lobe.
Two major fissures running mediolaterally divide the cerebellar cortex into three primary lobes
Primary fissure separates the corpus cerebelli into a posterior lobe and an anterior lobe
Posterolateral fissure separates the flocculonodular lobe from the posterior lobe.
——— is The largest and deepest fissure in the cerebellum
Horizontal fissure
Horizontal fissure
• It divides the posterior lobe of the cerebellum into an ——— and a ——- portion
The largest and deepest fissure in the cerebellum
• It divides the posterior lobe of the cerebellum into an upper and a lower portion (superior
posterior lobe and inferior posterior lobe)
Functional Zones
•The cerebellum can be divided by function into three functional areas/zones, the:
Functional Zones
•The cerebellum can be divided by function into three functional areas/zones, the:
• Cerebrocerebellum
•Spinocerebellum
•Vestibulocerebellum
Cerebrocerebellum
• Largest division, formed by the ——— hemispheres.
• It is involved in ———-
• It receives inputs from the cerebral cortex and ——— nuclei and sends outputs to the ——- and —— nucleus.
•This area also regulates coordination of muscle activation and is important in visually guided
movements.
Cerebrocerebellum
• Largest division, formed by the lateral hemispheres.
• It is involved in planning movements and motor learning.
• It receives inputs from the cerebral cortex and pontine nuclei and sends outputs to the thalamus and red nucleus.
•This area also regulates coordination of muscle activation and is important in visually guided
movements.
Spinocerebellum
•Comprised of the —— and ——— zone of the cerebellar hemispheres.
° It is involved in ———.
•It also receives proprioceptive information.
Spinocerebellum
•Comprised of the vermis and intermediate zone of the cerebellar hemispheres.
° It is involved in regulating body movements by allowing for error correction.
•It also receives proprioceptive information.
Vestibulocerebellum
•The functional equivalent to the ——— lobe.
° It is involved in controlling ———
•It receives inputs from the ——— system, and sends outputs back to the ——— nuclei.
Vestibulocerebellum
•The functional equivalent to the flocculonodular lobe.
° It is involved in controlling balance and ocular reflexes, mainly fixation on a target.
•It receives inputs from the vestibular system, and sends outputs back to the vestibular nuclei.
Functional Longitudinal Zones
Specific cerebellar afferent/efferent fibers are distributed to different zones of the cerebellum.
The four different zones are;
Functional Longitudinal Zones
Specific cerebellar afferent/efferent fibers are distributed to different zones of the cerebellum.
The four different zones are;
• Medial (Vermal) zone
• Intermediate (paravermal)
zone
• Lateral zone
• Flocculonodular zone
