Visual Perception (Kartei)

38 Karteikarten

• 1
  Far accomodation of the lens

  When the ring muscle relaxes the lens becomes stretched by ...
• 2
  Near accomodation of the lens

  Contraction of the ring muscle leads to relaxation of the ...
• 3
  Neurochemistry of the ring muscle

  Innervated by a parasympathetic nerve (mAchR) Muscarinic ...
• 4
  Sphincter muscle: Fast iris reflex

  - Sudden closure of the pupilla in response to light ...
• 5
  Dilatator muscle of iris

  - Antagonist of sphincter muscle - Sympathetic ...
• 6
  Types of photoreceptor cells: Rods

  - Outer segment (photosensitive part): Flat membrane disks ...
• 7
  Types of photoreceptor cells: Cones

  - Pleated outer plasma membrane - Specialized for good ...
• 8
  Synaptic ribbon

  Presynaptic structure in rods and cones that attracts ...
• 9
  Phototransduction: Membrane potential in the dark

  - Continuos influx of cations (calcium, sodium) into the ...
• 10
  Phototransduction: Membrane potential in light

  -> Hyperpolarizes to -80mV in the presence of bright light
• 11
  Chemistry of rhodopsin

  - Visual pigment, receptor molecule for photons - Composed ...
• 12
  Chemistry of cGMP

  - Cyclic guanosine monophosphate, a close relative of ...
• 13
  Light detection on a molecular level

  # Photons cause structural switch within the hydrocarbon ...
• 14
  Phototransduction: Signal amplification

  - For every rhodopsin activated by light ~500 G-proteins ...
• 15
  Phototransduction: Adaption to bright light

  # Light detected -> cGMP destroyed # cGMP-gated cation ...
• 16
  Bipolar cells in the dark

  - Constant release of glutamate at photoreceptor synapses ...
• 17
  Bipolar cells in light

  - Hyperpolarization, no neurotransmitter release
• 18
  Cone pathway vs rod pathway (types of bipolar cells)

  - Cone pathway: On-bipolar cells and off-bipolar cells - ...
• 19
  Cone pathway: On-bipolar cells

  - Metabotropic glutamate receptors (inhibitory synapse) - ...
• 20
  Cone pathway: Off-bipolar cells

  - Ionotropic glutamate receptors in off-bipolar cells ...
• 21
  Rod pathway: On-response

  - On-bipolar cells, metabotropic glutamate receptors - ...
• 22
  Rod pathway: Off-response

  - Amacrine cells release inhibitory neurotransmitter ...
• 23
  Horizontal cells in the dark

  Release inhibitory neurotransmitter GABA
• 24
  Horizontal cells in light

  - A photoreceptor cell hyperpolarizes - -> Horizontal cells ...
• 25
  Center-surround antagonism of retinal ganglion cells

  - Reason: Lateral inhibition by horizontal cells - ...
• 26
  On-center ganglion cells

  - Light in the center of the receptive field: Increase of ...
• 27
  Off-center ganglion cells

  - Light in the center of the receptive field: Decrease of ...
• 28
  Three types of retinal ganglion cells (structure)

  - Alpha-cells (Magnocellular pathway) - Beta-cells ...
• 29
  RGC: Alpha-cells (Magnocellular pathway)

  - Largest, have a wide dendritic tree - Specialized to ...
• 30
  RCG: Beta-cells (Parvocellular pathway)

  - Smaller - Fine-detail analysis, color vision
• 31
  Gamma-cells (nonM-nonP-cells)

  - Heterogeneous, irregular cell shape - Movement
• 32
  Neurochemistry of retinal axons

  Excitatory synapses, neurotransmitter glutamate
• 33
  Molecular basis of color sensitivity

  Color sensitivity depends on 15 amino acid differences in ...
• 34
  Blue-yellow opponency

  - Signals coming from red and green cones (yielding yellow) ...
• 35
  Optic tectum in mammals

  - Coordination center for eye movements, receives only ...
• 36
  Function of colliculus superior

  Control of eye movements - Oculomotor input - Efferent ...
• 37
  Function of colliculus inferior

  - Auditory input
• 38
  The human visual pathway

  - Receptor cells -- bipolar cells -- RGCs -- optic nerve -- ...