The Visual System
These particles of electromagnetic energy are the physical stimulus detected by photoreceptors in the retina.
What are photons?
This neurotransmitter from the substantia nigra pars compacta modulates striatal activity.
What is dopamine?
Degeneration of dopaminergic neurons in the substantia nigra pars compacta leads to this disorder.
What is Parkinson's disease?
This cortical region occupies the postcentral gyrus?
What is the primary somatosensory cortex (S1)?
This cranial nerve controls most eye movements.
What is oculomotor (CN III)?
These cells are the first in the retina to fire action potentials.
What are retinal ganglion cells (RGCs)?
This structure serves as the primary input nucleus of the basal ganglia.
What is the striatum?
A lesion of this region disrupts relay of visual information to the primary visual cortex.
What is the lateral geniculate nucleus (LGN)?
This type of peripheral receptor converts physical deformation of the skin, such as pressure or vibration, into neural signals.
What is mechanoreceptor?
Extending from the brainstem to the thoracic and abdominal organs, this is the longest cranial nerve.
What is vagus (CN X)?
This small depression in the retina contains the highest density of cones and provides the sharpest visual acuity.
What is the fovea?
Remember: rodents are non-foveate
The globus pallidus pars interna and this midbrain structure form the main output nuclei of the basal ganglia.
What is the substantia nigra pars reticulata?
Failure to detect two closely spaced points on the skin indicates dysfunction in this sensory pathway.
What is dorsal column-medial lemniscus (DCML)?
This sensory modality relies on mechanoreceptors in muscles and tendons to detect body position and movement.
What is proprioception?
Testing shoulder shrug against resistance assesses this cranial nerve.
What is accessory (CN XI)?
Fibers from this half of each retina cross at the optic chiasm.
What is the nasal retina?
The indirect pathway follows this sequence (starting in the striatum).
What is:
Striatum (D2-MSNs) --> GPe --> STN --> SNr/GPi
Hyperactivity in cortico-striato-thalamo-cortical loops contributes to the intrusive thoughts and repetitive behaviors characteristic of this condition.
What is obsessive compulsive disorder (OCD)?
Fine touch and proprioceptive information from the body synapse in this thalamic nucleus on the way to primary somatosensory cortex?
What is the VPL (ventral posterior lateral)?
While the glossopharyngeal (CN IX) and vagus (CN X) nerves contain nearly all functional fiber types, this is the one classification they do not include.
What is somatic motor (GSE, general somatic efferent)?
The ventral visual stream, also called the "what" pathway, follows this sequence.
What is:
retina --> optic nerve --> LGN --> V1 --> V2--> V4
During stop-signal or Go/No-Go tasks, this basal ganglia pathway is rapidly recruited to cancel a planned movement?
What is the hyperdirect pathway? Ctx --> STN
Disinhibition of the thalamus due to infarct of the subthalamic nucleus produces this violent flinging movement of the limbs.
What is hemiballismus?
Pain and temperature information from the body decussates at this location.
What is the spinal cord? (STT)
This pair of cranial nerves together conveys gustatory information from the tongue.
What is facial (CN VII; anterior tongue) and glossopharyngeal (CN IX: posterior tongue)?