MT2 Flashcards
Convergence
Multiple inputs converge onto a single cell
Diverge
A single cell’s output diverges to other cells
Temporal Summation
When multiple EPSP’s (excitatory postsynaptic potentials) arrive at the same synapse in quick succession to produce an AP
- single neuron to another single neuron
Spatial Summation
when multiple EPSP’s (excitatory postsynaptic potentials) are fired simultaneously at different synapses on the same postsynaptic neuron to produce an AP
- can be from multiple places
Sensory Transduciton
The process of converting physical energy into action potentials
[T/F] Sensory reception has no maximum or minimum
False
What is the labeled lines theory?
The brain recognizes distinct senses because the action potentials travel along separate nerve tracts
For the most part, what does a regular sensory pathway look like?
origin of sensation -> thalamus -> cortexes
- olfactory is the only perception
Different Visual Processes
- Low Level Processing
- Low Intermediate
- Object Recognition
Accomodation
process of changing the lens’ shape
Pupil
Small opening that controls the amount of light entering the eye
Optic Disc
The area at the back where optic nerves and blood vessels enter the eye
- “Blind spot”
Photorecetpors
- cells that detect light
- rods and cones
Cones
C(olour)ones, ~6 million in the eye, contains opsin
Rods
For low-light vision, ~100 million, contains rhodopsin
Opsin
Light sensitive proteins
Receptive fields
Areas in the retina that detect change in visual stimuli, ~1mm in diameter
Retinal ganglion cells
represents 1 receptive field in your vision
Visual Pathway
Photoreceptors -> bipolar cells -> RGC -> optic chiasm -> LGC -> Primary Visual Cortexes
Lateral Gengiculate Nucleus
Acts as a highway to bridge the cortex and the optic nerves, first level of processing is done here
Primary Visual Cortex (V1)
First station for higher order processing
contain hyper columns
Hyper-columns
- orientation columns, ocular dominance columns, blobs and strips
- For processing 1 receptive field in your visual field
V1, V2, V4, V5
As you go higher up the different cortexes the more complex processing it is doing
Dorsal- vs. ventral-stream
Dorsal (where), ventral (what)
Agnosia
Latin for lack of knowledge
Ataxia
e.g., reaching for objects
Apperceptive Agnosia
Ap-perceptive agnosia
lack of knowledge by perception (cant see the full picture)
Associative Agnosia
lack of knowledge by recognition and association (can’t label)
Prosopagnosia
facial recognition deficit
Processes in the Ear
External Ear (captures sounds/air-compressions) -> Ear drum (converts air compressions into vibrations -> Ossicles (amplify vibrations to oval window) -> Oval window (converts vibrations to pressure waves in cochlea) -> Cochlea (will with fluid and hairs that transduces vibrations into act, sits above the basilar membrane) -> Basilar membrane (transduces movement from hair in cochlea to graded potentials)
Why do hair cells in the cochlea handle afferent and efferent connections?
A(rriving CNS)fferent - sends sensory information to CNS
E(xiting CNS)fferent - will make hair cells longer or shorter, adjusting to acoustic environments
What are the points of long and short hair cells in frequency sensitivity
Different frequencies (shorter -> higher frequencies)
How does information from cochlea get to the cortex?
vestibulocochlear nerves
Auditory pathway
Ear -> cochlear nerve -> cochlear nuclei (filter out self and non-self sounds) -> superior olive nucleus (localize sound) -> inferior colliculus (for reflexes) -> medial geniculate nucleus (part of the thalamus) -> auditory cortex (higher order processing)
2 methods for localization of sound
inter-aural timing differences and inter-aural amplitude differences
horizontal plane localization for sound
inputs move on a horizontal field, which neuron the inputs from the right and left ear meet is how you local sound horizontally
vertical plane localization for sound
The use of your head’s shape and should will filter or enhance certain frequencies
Vestibular System
determining orientation of the head through liquids in ear
What are the 5 basic tastes
sweet, salty, bitter, umami, sour
what are the 3 different zones on your tongue
circumvallate, foliate, fungiform
what are papillae
bumps on your tongue that hold taste buds
what are taste buds
A formation of taste cells
what are taste cells
specific cells that are responsible for tasting a single flavour
what is the science behind a super taster
They have more concentration of taste buds, especially bitter ones
How is taste cortically processed?
In distinct areas of the brain
How do we perceive odours?
molecules in the air that dissolve into our olfactory epithelium
Anatomical Pathway for smell
olfactory epithelium (consists of sensory neurons) -> converge into olfactory buld (organization of converging neuron axons) -> olfactory glomeruli (convergence of specific smell receptors)
What are the different layers of the skin
epidermeris (outermost layer) -> dermis (middle layer, has nerves) -> hypo-dermis (inner most layer, anchors skin to muscles)
4 different cells for touch?
Meissner corpuscles (texture), Merkel cell (change in touch), pacinian corpuscles (vibrations), ruffini endings (skin stretch)
What are the 2 adapting types for touch cells
rapid (signal change in touch), slow (signal constant touch)
Touch receptive fields
Similar to vision receptive fields
What are kinaesthetic receptors
responsible for knowing the location of limbs in 3D space (in muscles and joints)
nociceptors
peripheral receptors that respond to pain
Neuropathic pain
Pain caused by lesion or disease in the somatosensory nervous system
Opiates
Pain reducing drug
Opioids
opiate-like peptides
Periaqueductal Gray
Area of the brain responsible for pain perception
what are placebo’s
bigger the pill, body better receives that medication (nothing biological, all mental)
Naloxone
Opioid antagonist, reduces the effects of opiates and opioids
Analgesia
produced when under stress, regulates pain receptors
