Special Sensory Flashcards
The optic nerve has info from one or both eyes?
One
Each optic nerve tract sends axons to what three major locations?
1) hypothalamus
2) Midbrain
3) Primary visual cortex
Where does visual perception take place?
The primary visual cortex
Visual recognition takes place where?
Visual association cortex
What is the pathway of the hearing process?
Sound hits eardrum it then vibrates and transmits the vibration into the middle ear
middle ear, auditory ossicles, transmit vibration caused by sound waves through middle ear cavity into inner ear
In the cochlea:
Movement of the tectorial membrane pulls on the tips of the hair cells embedded in it, causing them to bend.
Bending of the hair cells releases a neurotransmitter that activates the vestibulocochlear nerve.
Which tract primarily controls muscles and maintains balance?
vestibulospinal tracts
When light strikes the retina it stimulates cells called
Photoreceptors
-cones and rods
What cranial nerve is the eyeball connected to
CN II
the optic nerves meet to form what
optic chiasm
in the optic chiasm what percent of the optic nerves cross
50%
What projections come from visual association cortex
visual recognition
What projections come from parietal lobe
- locating objects in space
- perceiving spatial relationships
What projections come from temporal lobe
determine size, shape, color, and texture of what we are seeing
What causes Hemianopsia
damage to one optic tract
damage to primary visual cortex
on one side causes loss of vision on opposite field
what is a common effect from a CVA
hemianopsia
what is cortical blindness
person cannot perceive anything
when does cortical blindness occur
when patient has damage to visual cortex on both sides
what are the two parts of the inner ear
- cochlea
- vestibular apparatus
what is cochlea for
hearing
what is vestibular apparatus for
balance
what occurs in cochlea
hair cells bend and release a neurotransmitter that activates the vestibulocochlear nerve
what are the two parts of the vestibular apparatus
- otolithic organs
- semicircular canals
what do the otolithic organs do
detect linear movement of the head
utricle-horizontal
saccule-vertical
what condition causes hearing loss due to fractures or malformation of the auditory ossicles
osteogenesis imperfect
what is meniers disease
condition in which excess endolymph causes swelling inside the vestibular apparatus and cochlea
what are symptoms of meniers disease
debilitating vertigo and hearing loss
