Neuroscience Flashcards
Where is the homunculus located?
On either side of the central gyrus (separates frontal & parietal lobes)
Where is the cerebellum located?
Underneath cerebrum, behind the brain stem
What are the 3 types of movements?
- Reflex
- Rhythmic motor patterns (automatic, e.g. chewing, walking)
- Voluntary movement (require conscious control)
What does movement require?
- Sensory info coming in
- Processing of info at an automatic and/or cognitive level
- Executing a response with the correct amount/timing of muscle activity
- Ability to rapidly modify response
- Learning & memory
Where does sensory info come from?
- Visual
- Vestibular
- Somatosensory (including tactile & kinaesthetic sensation)
What is the function of the visual system?
- Sight
- Eye movement control
- Info for postural and limb movement
What is the visual system made up of?
- Retina
- Afferent pathways (optic nerve, thalamic/vestibular connections, cortical connections for perception)
- Efferent connections (eye movements)
What are the 3 pathways that transmit visual info to the CNS?
- Lateral geniculate of thalamus
- Occipitotemporal region (visual object identification)
- Posterior parietal cortex (visual guidance) - Tectum
- Visually guided eye movements (orientation) - Pretectal area
- Pupillary reflexes
What are the functions of the vestibular system?
- Provides info about direction & speed of head movement
- Position of head relative to gravity
- Gaze stabilisation
- Postural adjustments
- Autonomic function & consciousness
What is the vestibular system made up of?
- Vestibular apparatus/labyrinths (semicircular canals, utricle & saccule located in inner ear)
- Afferent connections (vestibular nerve, connections to vestibular nuclei & cerebellum)
What are the functions of the vestibular apparatus/labyrinths?
Semicircular canals
- Directional specific, acceleratory forces
- Give 3D picture
Otoliths (utricle & saccule)
- Respond to vertical/linear displacement
- Respond to gravity
What is the main vestibular afferent pathway?
Vestibular nerve
- Vestibular nuclei in medulla/pons
- Flocculonodular lobe of cerebellum
What is the central vestibular system made up of?
- 4 nuclei
- 6 pathways
- Vestibulocerebellum
- Vestibular cortex
What does somatosensation include?
- Touch
- Pain
- Temperature
- Vibration
- Proprioception
What contributes to somatosensation?
- Receptors
- Somatosensory pathways
- Conscious relay pathways
How is afferent somatosensory information transmitted?
- Ascending sensory pathways
- Important connections in brain stem, thalamus
- Important cortical regions (perception)
What are the different types of sensory pathways?
Conscious relay
- Location/type of stimulation
- Accurate/discriminative info
Divergent
- Transmit to many locations
- Conscious & unconscious
Unconscious relay
- Proprioceptive/movement related info
- Automatic adjustments of movement/posture
What are the ascending sensory pathways?
- Dorsal columns
- Anterior & lateral spinothalamic
- Spinocerebellar: Unconscious movement-related info