Specific Senses (5/11) Flashcards
Pathway for vision
Detect visual stimuli
convert to action potentials
send to brain
Retina
Turns certain wavelengths of light into action potentials
- contains cones (colors)
- contains rods (night vision)
Where are cones located
In the retina inside of the fovea centralis and macula
Rhodopsin
protein very sensitive to light in rods
Location of rods
many many more and cones and located further from the retina so peripheral vision is best for seeing dimly lit objects at night
Lens and cornea
cornea- first thing light passes through and protects eye
Lens- finishes job of focusing light
Iris
has a hole in center known as pupil (what actually lets light into eye) while iris acts as an umbrella to not let any excess light in
Dilator pupillae muscle
increases pupil size
Constrictor pupillae muscle
decreases muscle size
When lens changes shape…
by Ciliary body via suspensory ligament of lens
Anterior chamber (front area)
contains aqueous humor
Posterior chamber (back of the eye)
Contains vitreous humor
Beneath the retina lays a dark layer of tissue called…
Choroid - supplies blood and absorbs extra light
Outer most layer
Sclera (white color)
Cones and rods are…
synapsed to bipolar cells which then synapse to ganglia cells
Cells that are horizontal
horizontal cells are between cones/rods and bipolar cells and they inhibit photoreceptors
Amacrine cells
Between bipolar cells and ganglion cells
Visual fields
left and right
Optic Chiasm
where the fields cross and shoved to opposite side of brain
so, visuals that hit right side of left processed in right
so, visuals that hit left side of right get processed in left
outer halves of each eye stay on the same side of the brain
Optic tract
runs through the lateral geniculate nucleus (LGN) contained in the thalamus
LGN
contains magnocellular neurons- motion but no details and parvocellular neurons (small)- details but not motion
Temporal resolution
detecting change
Motion paralax
objects closer to us move further across our visual field than objects that are far from us
Feature dections
Detection of individual stimuli
Parallel processing
integrating multiple stimuli
Serial memory processing
systematically giving attention to one thing at a time
Order of visual pathway
Photoreceptors horizontal cells bipolar cells amacrine cells ganglion cells
Sterocilia
hair cells of the ear that poke out into fluid called the endolymph
Moving of sterocilia in endolymph triggers…
calcium channels to open and the influx of calcium causes the release of neurotransmitters
ORgan of corti
has a flexible structure called the basilar membrane, hair cells, and tectorial membrane
Summery of path of waves entering ear
sound waves enter and cause the endolymph that surrounds hair cells to vibrate and cause hair cells to release neurotransmitters to go into brain
outer eat
lobe, pinna/auoricle and they funnel airwaves
Eardrum
dividing point between outer ear and middle ear
Middle ear
ossicles: malleus, incus, and stapes Eustachian tube (equalizes pressure- does the popping)
Oval window
stapes connected to and it is the boundary between the middle ear and the inner ear
Inner ear
fluid bathed hair cells
known as bony labyrinth (contains perilymph) and the membranous labyrinth (contains endolymph)
More on inner ear
Cochlea: scala vestibule (contains perilymph) and scala tympani (contains perilymph) and reissner’s membrane
Thickness of basilar membrane (place theory)
thick= high frequency narrow= low frequency closer to apex and further from oval window
Parts of brain involved in hearing
auditory cortex and medial geniculate nucleus
Vestibular sense
hair helps with balance semicircular canals sense circular motion vestibule- linear execration utricle- horizontal motion saccule- vertical motion they contain otoliths which have CaCO3
Sound
determined by amplitude and vibrates tympanic membrane
Touch
somatosenation: touch, pain, temperature, etc
Nerves of skin
Not distributed evenly in the skin
fingertips are sensitive and have a high density of nerves
Two-point threshold
minimum distance for distinguishing two point stimuli
Homunculus
little man drawn to shown density of nerves
Gate theory of pain
Pain turned on/off based on input
spinal cord
Taste
information is first processed in the thalamus then gustatory contex
Smell
in olfactory bulb and passed to olfactory tract
limbic system
Interacting sense
flavor is a combination of tase and smell
Two-point threshold definition
the minimum distance between two points on the skin that are stimulated at the same time such that we can perceive them as distinct from each other
