| Term | Definition |
| Relation of the Cerebellum and the cerebral hemispheres | -Has more neurons than the cerebral hemispheres
-Communicates with cerebral hemispheres through the brain stem. Enters through the medulla and pons |
| Functions of the cerebellum | -Error Control Device
–Modifies motor movements from the cortex
-Makes modifications in rest of body to make a particular movement more fluid.
-People with cerebellum issues have jerky movements. |
| Ataxic dysarthia | -Jerky movements.
-Think about each movement.
-Coordination not there to make speech sounds(phonation starts before the plosive).
-Characterized by Scanning Speech & Slurred and Disjointed Speech
-usually due to ipsilateral lesion in cerebellum. |
| Posterior Fossa | -Cavity in cranium where Cerebellum sits |
| Tentorium Cerebelli | Extension of the meninges that cover the brain and separate the cerebrum from the cerebellum. |
| Parts of the Cerebellum | 3 Lobes
-Floccular Nodular
-Anterior
-Posterior |
| Longitudinal Cortices regions of the Cerebellum | 1. Median (Vermal)
2. Paramedian (Paravermal
3. Lateral |
| Nucleus | -Refers to a group of neurons (cell bodies) deep in a structure
-found in gray matter |
| Dentate nucleus | -Largest nucleus of the Cerebellum
-Communicates through cerebellar peduncle
-Carries information important for coordination of limb movements (along with the motor cortex and basal ganglia) |
| Emboliform and Globose nucleus | -Two Nuclei of the Cerebellum
-Regulate movements of ipsilateral extremities |
| Fastigial nucleus | -Nucleus of the Cerebellum
-Regulates body posture
-Is related to the flocculo nodular lobe (also involved in the vestibular system) |
| Pontine Projections | Axons going away from and towards the pons. |
| Superior Cerebellar Peduncle | -Carries info away from dentate Nucleus towards the pons.
-Pathways away from and towards the brain stem |
| 2 types of somatotopic organization in the Cerebellum | Sensory and Motor
- specefic parts of cerebellum process sensory and motor info for specific areas of the body |
| Sensorimotor Somatotopically representation of the body in the Cerebellum | -Ipsilateral in anterior lobule
-Bilateral in posterior lobe
-Cerebral Cortex and Cerebellum have similar sensory representations
-Motor areas may have auditory and visual processing |
| Floccular nodular lobe aka Archicerebellum lobe | -Lobe of the cerebellum
-Has input from vestibular part of VIII cranial nerve
-Regulates equilibrium through vestibulospinal tract
-First to develop |
| Anterior lobe aka Paleocerebellum lobe | -Lobe of the cerebellum
-Rostral to Primary Fissure
-General Sensory Receptors
-Concerned with muscle tone and walking |
| Posterior lobe aka Neocerebellum | -Lobe of cerebellum
-Receives projections from contralateral sensorimotor cortex
-Projects to contralateral motor cortex by dentate nucleus, red nucleus and thalamus
-Aids in coordination of fine and skilled movements
-Largest
-Last to develop |
| Median (Vermal) region of the Cerebellum | -Located in middle of 2 hemispheres of the cerebellum
-Contributes to body posture (related to flocular nodular lobes) |
| Paramedian (Paravermal) region of the cerebellum | Regulates movements of ipsilateral extremities (e.g. walking) |
| Lateral region of the cerebellum | Regulates skilled movements of ipsilateral extremity (e.g. tying your shoe) |
| Three Peduncles of the cerebellum | Connects the Cerebellum to the brain stem. |
| Inferior and Middle Peduncles | -Cerebellum Penducle
-Carries afferent info towards the cerebellum
-Mediates sensorimotor input to the cerebellum |
| Superior Peduncle | -Cerebellum Penducle
-Transmit output from the cerebellum to the brainstem and on to the thalamus, motor cortex, and spinal cord (important for motor plans)
-Efferent |
| Origins of Afferent projections to the Cerebellum | -spinal cord
-brainstem
-motor cortex
-Afferent to Efferent Axon Ratio 40:1 |
| Vestibulocerebellar Tract | -Fiber bundle that enters the cerebellum through the inferior cerebellar penduncle.
-Sends info from Semicircular Canals
-Maintains Upright Posture
-Most of this info goes to the frocular nodular lobe |
| Dorsal Spinocerebellar Tract | -Fiber bundle that enters the cerebellum through the inferior cerebellar penduncle.
-Brings info From Reticular Formation of the brainstem
-Important for unconscious Proprioception From Muscle Spindles, Golgi Tendons and Tactile Receptors |
| Reticulocerebellar Tract | -Fiber bundle that enters the cerebellum through the inferior cerebellar penduncle.
-brings Info From Cerebral Cortices, Spinal Cord, Vestibular Complex, and Red Nucleus |
| Olivocerebellar Tract | -Fiber bundle that enters the cerebellum through the inferior cerebellar penduncle.
-Carries info from Spinal Cord through Olivary N to Contralateral Cerebellar Hemisphere
-Source of Climbing Fibers for Direct Input to Cerebellum from the spinal cord |
| Cuneocerebellar Tract | -Enters cerebellum via the middle cerebellar peduncle
-Mediate Proprioception from Upper Limbs & Neck
-Carries info From Pontine Nuclei From Opposite Cerebral Cortex, Visual and Auditory Inputs To Opposite Cerebellar Hemisphere |
| Destinations for efferent pathways from | -Go Through Superior Cerebellar Peduncle to the:
-Red Nucleus (Brainstem)
-Thalamus
-Motor Cortex |
| Three Layers of the Cerebellum | 1. Molecular
2. Purkinje
3. Granular |
| Molecular | Most external layer of the cerebellum |
| Purkinje | -Connecting Surface and Deep Cerebellar Nuclei
-Source of All Efferent Fibers
-Middle layer of the Cerebellum |
| Granular | -Layer of the Cerebellum that has Mossy Fiber Axons that carry info towards the Purkinje Axons.
-Deepest layer of the Cerebellum |
| Signs of cerebellum issues | -Impaired Muscle Synergy (person walks like a robot)
-Reduced Muscle Tone
-Evident in Skilled Tasks |
| Ataxia | -Lack of Order and Coordination in Activities
-Slow Movement (Bradykinesia)
-Mild Muscular Weakness (Asthenia)
-Lack of fluid movement (Asynergia) |
| Dysdiadochokinesia | -Clumsiness in Alternating Movements
-Tapping for each Speech Sound used to treat this |
| Dysmetria | -Causes error in Judgment of Range and Distance of Target
-Characterized by undershooting or Overshooting |
| Intentional Tremor | -Accessory Movement During Volitional Task (hand steady when limb but tremor when doing something like brushing teeth) |
| Hypotonia | Reduced Resistance to Passive Stretch |
| Rebounding | -Inability to Predict Movement
-Cannot Hold Back Movement |
| Disequilibrium | -Unsteady Gait, Body Wavering
-deals with the focular nodular lobes |
| Cerebrovascular Accident (CVA)- aka stroke of the cerebellum | -Can be thrombotic, embolic or hemorrhagic
-Location of theses strokes usually in the Vertebrobasilar Artery |
| Thrombotic stroke | When artery is blocked by plaque build up inside artery. |
| Embolic stroke | When plaque breaks off from a larger artery and flows down to a smaller artery and blocks it. |
| Hemorrhagic Stroke | Brain bleed, bursting of an artery |
| Vertebrobasilar Artery | Artery that supplies the occipital lobe and the cerebellum |
| Toxicity | -May cause cerebellar degeneration
-Characterized by wide based shuffling
-Can cause Kosicoff syndrom (no short term memory) |
| Friedrich's Ataxia | -Progressive Cerebellar Degeneration
-Hereditary condition
-Is a gradual sheering of the cerebellum. Very diffused axial breakdown
-Characterized by Sensory and Motor Dysfunctions |
