Neuro ppt 2 Flashcards
Which tract enters the cerebellum via the inferior cerebellar peduncle and carries signals about muscle contraction and body position?
Dorsal Spinocerebellar Tract
What is the function of the Vestibulocerebellum?
Controls postural and equilibrium adjustments.
- Coordinates with vestibular apparatus and vestibular nuclei in controlling equilibrium and postural adjustments
Which cerebellar region fine-tunes reciprocal actions of agonist/antagonist muscles in hand and finger movements?
Spinocerebellum
The cerebrocerebellum coordinates which type of motor activities?
Sequential motor activities initiated by the cerebral cortex.
What neurotransmitter transmits inhibitory signals between the substantia nigra and the putamen?
Dopamine
Name two circuits of the basal ganglia and their primary functions.
Putamen Circuit: Controls complex movement patterns (e.g., typing).
Caudate Circuit: Generates rapid, subconscious movement patterns.
Which basal ganglia circuit involves signals from premotor areas and coordinates movement through the primary motor cortex?
Putamen Circuit
Reflexes and rhythmic movements are controlled at which level of the motor system?
Spinal cord
What is the primary role of the hindbrain in motor control?
Maintains balance and adjusts muscle tone to maintain equilibrium.
(Maintains axial body tone for standing and continuously modifies muscle tone to maintain equilibrium in response to signals from vestibular apparatuses)
Which accessory motor control structure monitors and adjusts motor activity during rapid movement?
Cerebellum
Which association area of the cerebral cortex interprets somatosensory, visual, and auditory signals?
Parieto-Occipitotemporal Association Area
The prefrontal cortex is responsible for which functions?
- Working memory
- Problem solving
- Ordering of tasks to achieve a goal
- Ability to perform tasks in parallel
- Modulation of mood, social interactions, and motivation
- Ability to carry through a train of thought
- Elaboration of thought
How does the corpus callosum assist in brain communication?
It allows bidirectional communication between the two cerebral hemispheres.
What is the primary entry point for sensory signals in the cerebral cortex?
Layer IV
What is memory consolidation?
The process of converting short-term memory into long-term memory through repeated activation and synaptic changes.
What are the three types of memory based on timing?
Short-term: Seconds to minutes
Intermediate long-term: Days to weeks
Long-term: Lifetime
Declarative memory stores details of what?
Surroundings, time relationships, and meanings of experiences.
Which brain structure is critical for classifying memories to facilitate retrieval?
Hippocampus
Which neurotransmitter produces excitatory signals in the basal ganglia?
Glutamate
Wernicke’s area is responsible for what function?
Language comprehension.
Broca’s area is responsible for what function?
Language formation.
What allows anterior portions of the temporal lobes to communicate bidirectionally?
Anterior commissure
Which tract sends motor signals to the cerebellum via the superior cerebellar peduncle?
Ventral Spinocerebellar Tract
Which cerebellar tract transmits sensory signals to the reticular formation?
Spinoreticular Tract
What role does the spino-olivary tract play in the cerebellum?
Transmits signals from the spinal cord to the inferior olivary nucleus to cerebellum
Which basal ganglia circuit is associated with rapid and subconscious movement patterns?
Caudate Circuit
What is the role of GABA in the basal ganglia?
Inhibitory signal transmission between caudate nucleus/putamen and globus pallidus/substantia nigra.
Which neurotransmitter is involved in signal transmission from the cerebral cortex to the caudate nucleus and putamen?
Acetylcholine
What structures connect the two hemispheres of the brain for communication?
Corpus callosum and anterior commissure
What is the function of the anterior commissure?
Allows bidirectional communication between the anterior portions of the temporal lobes.
What is the primary sensory entry point in the thalamocortical system?
Thalamus
Which type of memory is associated with motor activities?
Skill memory
What is the function of the limbic system?
Regulates behavior, emotion, and motivation.
Which area of the brain is responsible for language comprehension?
Wernicke’s area
Which cerebral cortex area is involved in planning complex sequences of movement? and thought processes?
Prefrontal Association Area
How do layers II and III of the cerebral cortex contribute to brain function?
Send signals across hemispheres via the corpus callosum.
Which neurotransmitter produces excitatory signals in the basal ganglia?
Glutamate
What is consolidation?
Conversion of short-term memory to long-term memory
What is rehearsal re. memory?
Repeated activation of ‘memory strand’ initiates chemical, physical, and anatomical changes of the synapses, more frequent repetition accelerates rate of consolidation
Codification is:
Classification of memories relative to existing memories to facilitate memory retrieval
Anterograde amnesia
Loss of ability to form new declarative memories
Retrograde amnesia
Difficulty recalling past memories
o May occur in conjunction with anterograde amnesia in event of hippocampal injury, or independent of anterograde amnesia in event of thalamic injury
Memory storage: Short term
Reverberating circuits or presynaptic facilitation/inhibition
Memory storage: Intermediate long-term
Temporary chemical or physical changes of presynaptic terminals or postsynaptic cell membranes
Memory storage: long-term
Structural changes
What are the structural changes of long-term memory?
Increased number of vesicle release sites
* Increased number of transmitter vesicles
* Increased number of presynaptic terminals
* Changes in structure of dendritic spines to allowing transmission of stronger signals
Declarative memory
Details of a memory (e.g., surroundings, time relationships, meaning of experience)
What is a thought?
Pattern of neural activity within central nervous system (e.g., cerebral cortex, thalamus, limbic system, reticular formation)
What is conciousness?
“…continuing stream of awareness of either our surroundings or our sequential thoughts.”
what is a memory?
Memory: Stored in brain by altering sensitivity of synaptic transmission due to previous neural activity
What is the function of an Association Area?
“…receive and analyze signals simultaneously from multiple regions of both the motor and sensory cortices…”
What is the function of the Prefrontal Association Area?
Receives ‘pre-analyzed’ sensory information from parieto-occipitotemporal association area via subcortical nerve bundle in order to plan complex sequences of movement and initiate thought processing
** Capable of processing non-motor sensory information and storing ‘working memories’
Function of the Limbic Association Area:
Involved in regulation of behavior, emotion, and motivation
* Emotional drives activate other areas of brain
Cerebral cortices have independent capability for:
consciousness, memory storage, communication, and motor control
Dominant Hemisphere:
- Dominant Hemisphere: Concept that general interpretative functions and motor control are better developed in one cerebral hemisphere
- In 95% of population, left hemisphere is larger at birth (e.g.., Wernicke’s/Broca’s areas), resulting in preferential use of this side of developing brain
- Dominance of left cerebral cortex motor cortex provides right-hand dominance in 90% of population
What is the Angular gyrus?
a visual association area that transmits signals created by reading words to Wernicke’s area
Peripheral Afferent Tracts to Cerebellum: (4)
- Dorsal Spinocerebellar Tract:
- Ventral Spinocerebellar Tract:
- Spinoreticular Tract:
- Spino-Olivary Tract:
Efferent Tracts from Cerebellum: (3)
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
Dorsal Spinocerebellar Tract pathway
Spinal fibers enter cerebellum via inferior cerebellar peduncle and terminate in vermis and intermediate zones on ipsilateral side
Dorsal Spinocerebellar Tract signal origin
Signals primarily originate from muscle spindles as well as Golgi tendon organs, tactile receptors of the skin, and joint receptors
Dorsal Spinocerebellar Tract signals indicate:
Signals indicate status of muscle contraction, tension on muscle tendons, position and rate of movement of body parts, and surface forces
Ventral Spinocerebellar Tract pathway
Spinal fibers enter cerebellum via superior cerebellar peduncle and terminate bilaterally
Ventral Spinocerebellar Tract origin
Signals primarily originate from anterior horn of spinal cord
Ventral Spinocerebellar Tract signals indicate:
Signals indicate arrival of motor signals to anterior horn
Vestibulocerebellum pathway
Vermis → fastigial nuclei → medulla and pons
Vestibulocerebellum function
Coordinates with vestibular apparatus and vestibular nuclei in controlling equilibrium and postural adjustments
Spinocerebellum pathway
Intermediate Zone → interposed nucleus → thalamus → cerebral cortex → thalamus → basal ganglia → red nucleus and reticular formation
Spinocerebellum function
Coordinates reciprocal actions of agonist/antagonist muscles in hands and fingers
Cerebrocerebellum pathway:
Lateral Zone → dentate nucleus → thalamus → cerebral cortex
Cerebrocerebellum function:
Coordinates sequential motor activities initiated by cerebral cortex
Basal ganglia function
Accessory motor system that functions with cerebral cortex and corticospinal tract
Basal ganglia structures:
Structures include caudate nucleus, putamen, globus pallidus, substantia nigra, and subthalamic nucleus
* Structures surround thalamus
Putamen circuit function:
Coordinate with corticospinal tract to control complex patterns of movement
Putamen circuit signal pathway
Initiate in premotor, supplementary motor, and somatosensory areas,
- Signals are transmitted through putamen, internal portion of globus pallidus, and ventroanterior/ventrolateral nuclei of thalamus
- Accessory circuits are transmitted through external portion of globus pallidus, subthalamus, and substantia nigra
- Signals return to primary motor cortex
Caudate circuit signal pathway
- Signals are initiated in association areas of cerebral cortex
- Signals are transmitted through caudate nucleus, internal portion of globus pallidus, and ventroanterior/ventrolateral nuclei of thalamus
- Signals return to prefrontal, premotor, and supplementary motor areas
Accessory motor control structures: (3)
Cerebellum, basal ganglia, limbic system
Cerebellum functions (3)
- Interacts with spinal cord to enhance stretch reflex
- Controls axial body to maintain equilibrium
- Interacts with cerebral cortex to sequence, monitor, and adjust motor activity during rapid movement
Function of basal ganglia
Facilitates execution of learned movement patterns and plans parallel and sequential patterns of movement
Function of limbic system
Motivational system that includes the hypothalamus, amygdala, hippocampus
Function of spinal cord
Reflexes, rhythmic movement, reciprocal movement; may be commanded or inhibited by higher levels
Function of motor cortex
Transmits motor signals to spinal cord that may modify or bypass spinal cord signals
Function of Parieto-Occipitotemporal Area
Performs continuous analysis of visuospatial information to coordinate movement of body and understand surroundings
What is the Parieto-Occipitotemporal Area?
Area between posterior parietal cortex and superior occipital cortex receives visual sensory information from posterior occipital cortex and somatosensory information from anterior parietal cortex
Cerebral cortex layers Layers I & II:
Receive diffuse input for excitability control
Cerebral cortex layers Layers V & VI:
Project to brain stem and spinal cord, controlling signal transmission and influencing thalamic activity
Cerebral cortex histologic structure (3)
- Granular: Interneurons that transmit signals only short distances
- Pyramidal: Long, large neurons that transmit signals to spinal cord as well as subcortical association fiber bundles
- Fusiform: Similar function as pyramidal cells
Cerebral cortex connection types: (2)
- Horizontal Connections: Communicate between adjacent areas of brain
- Vertical Connections: Communicate between cerebral cortex and lower levels of central nerve system
Thalamocortical System
Two way communication between thalamus and multiple areas of cerebral cortex
- Most sensory information is transmitted to cerebral cortex by thalamus
- Primary motor cortices have direct connections to specific muscles and primary somatosensory cortices detect specific sensations
- Secondary areas help to discern signals from the primary cortices
Dopamine’s role in basal ganglia
Involved in inhibitory signal transmission between the substantia nigra and caudate nucleus/putamen
Neurotransmitters of the basal ganglia:
- Dopamine
- GABA
*Acetylcholine
*Glutamate - Norepinephrine
- serotonin
- enkephalin
