test 2 Flashcards
nocioception
pain, pressure, itch
proprioception
body awareness and head movement
hapsis
fine touch and pressure
what is speed determined by?
myelin and diameter
fashion in which information enters the spinal cord
orderly
what’s a dermatome
area of skin that sends information to a single dorsal-root ganglion
how does information enter the spinal cord?
via the dorsal-root ganglion
in what fashion does sensory information enter the ventral posterior nucleus of the thalamus
contralateral-ly
where is sensory information processed (mainly)
in the primary somatosensory cortex
where is the primary somatosensory cortex located
in the parietal lobe just posterior to the central sulcus
what information does the right vs left primary somatosensory cortex process
right cortex - right side of the body
left cortex - left side of the body
what is the receptive field of a neuron
a region of physical space where it is possible for a physical stimulus to alter the firing rate of the neuron being measured
how is a dermatome different from a receptive field
receptive fields are large and can overlap
what does touching the center of the receptive field cause?
increase in firing rate
what does touching the surrounging of the receptive field cause?
decrease in firing rate
what is plasticity?
the ability of brain structures to change to better cope with the environment
where is the primary motor cortex located
frontal lobe just anterior to the central sulcus
what does crossing the midline mean in the context of this course?
hemispheres controlling the other side of the body (both sensory and motor)
what directly controls the muscles?
spinal motor neurons (not the motor cortex directly)
what’s a motor unit?
a single spinal motor neuron and all of the individual muscle fibers it contacts
neurotransmitter used by neurons to “talk to” muscles
acetylcholine
receptor systems that monitor the status of a muscle
muscle spindle neurons
what/why is the stretch reflex (knee hitting thingy)
when a muscle gets stretched it increases the firing rate of the neurons and the body makes an immediate effort to work against that stretch
top-down control of reflexes
we subconsciously inhibit some reflexes (like the babinski reflex). loss of this control indicates damage
amplitude in light waves
brightness
wavelength of light waves
color
sympathetic vs parasympathetic nervous system on the pupil
sympathetic - pupil dilation
parasympathetic - pupil constriction (via acetylcholine)
extra: atropine prevents pupil constriction
sensitivity (pupil)
larger pupil, more light let in, good for dimly lit environments
acuity (pupil)
smaller pupil, sharper image, good for seeing detail
what is binocular disparity
images on each retina being offset, allows us to see depth
what is the sense organ for vision?
the retina
what are the receptors for light (vision)
rods and cones
how is the “issue” of light being filtered and distorted through the layers of neurons
the fovea where the retinal ganglion layer is basically nonexistent
axons must pass through the retina at some point
that creates the blind spot, a solution for the missing spot is called “completion”
cones vs rods light perception
cones - color
rods - light
cones vs rods sensitivity and why
cones are more accurate but less sensitive and rods are the opposite because of the amount of them that respond to a single ganglion cell
what do rods do in response to light? (axons)
rods don’t fire in response to light, they actually stop firing. that in turn tho causes the ganglion cells to fire
how does the information leave the eye
axons from the retinal ganglion cells exit the eye through the optic nerve
visual fields
both eyes see both visual fields but the information from the left visual field goes to the right primary visual cortex and vice versa
how are visual fields split
the retinas are split into the visual fields at the retina. they are split into the nasal and temporal hemiretina
how do the visual fields get to the right cortexes
the axons from each nasal hemiretinal cross the midline
what are the physical stimulus for vision and audition
vision - light waves
audition - sound vibrations
amplitude in sound
loudness
frequency in sound
pitch
how do the vibrations travel through the ear
tympanic membrane (eardrum) –> ossicles (the three little bones) –> oval window –> cochlea –> organ of corti –> hair cells
sense organ for audition
organ of corti
sound receptors
hair cells
how do hair cells bla bla yk what i mean
they are moved physically which mechanically causes ion channels to open. depolarization of the hair cells causes neurotransmitters to be released which causes a chain reaction
different areas of the organ of corti respond to different frequencies
tonotopic map, similar frequencies next to each other
where is the primary auditory cortex
in the temporal lobe
what’s the organization in the primary auditory cortex
columnar organization that corresponds to the tonotopic map
anterior vs posterior auditory pathway
anterior - what
posterior - where
how do we locate sound
inter-aural timing differences
what’s the vestibular sense
sense of balance (and head movement). a kind of proprioception
what’s the sense organ of the vestibular system
semicircular canals
what’s the receptor for the vestibular sense
hair cells
how is the vestibular information processed
travels along the cranial nerve, is processed by the brainstem and the cerebellum. works in close collaboration with other systems, especially the visual system
what’s an example of the vestibular and visual systems working together
the vestibular-ocular reflex. you can move your head and the image remains stable
what are some similarities between the systems
contralateral projections (everything is swapped left to right and right to left). orderly representation. top down control. thalamus
which parts of the thalamus are the different senses processed in
vision - lateral geniculate nucleus
audition - medial geniculate nucleus
somatosensation - ventral posterior nucleus
orderly representation of the visual stimulus
retinotopic map, neurons for light next to each other are next to each other
disproportionate representation
visual - at the fovea
sensory and motor - face and hands
visual receptive field
an area of visual space where it is possible for light to change the firing rate of a neuron
light in the center vs off center vs both
center - increased firing rate
off center - decreased firing rate
both - basically unchanged firing rate
ventral vs dorsal streams (for vision)
ventral - what
dorsal - where
