Visual and Auditory systems Flashcards
Sensory Receptors
cells that convert energy to neural activity
Vision Receptors
Light is converted to chemical energy
Auditory Receptors
Air pressure converted to mechanical energy
Somatosensory Receptors
Mechanical energy activates mechanoreceptors
Gustatory/Olfactory Receptors
Molecules fit to receptors
Pain Receptors
Tissue damage releases chemicals
What happens when the hair on an arm is displaced?
the dendrite of a somatosensory neuron is wrapped around the base of a hair. When the hair is displaced, the dendrite is stretched by the displacement
What happens in response to a dendrite stretching?
Sodium channels open which leads to an action potentioal
Receptive Fields
Neurons have these–> part that only responds to a specific stimulus
Rapidly Adapting Receptors
Detect whether something is there
Slowly Adapting Receptors
React to stimulation more slowly
Exteroreceptive
Receptors that respond to external stimuli
Interoreceptive
Receptors that respond to our own activity
Periaqueductal Gray Matter
Pain pathway
Where does message modification occur?
At Neural Relays
Gating
Inhibition of sensory information
Why we dont feel possible sever pain when excited
Topographic Organization
a neural spatial representation of the world
Different regions of the brain represent different aspects of the sensory input
Rods
photoreceptor that is sensitive to dim light
Mainly used for night vision
Cones
Used for daytime vision
Signal spatial detail and color
Where are cones located?
in the foveal region
Where are rods located?
the rest of the retina
Retinal Ganglion Cells
collect at the blind spot and leave to form the optic nerve
Optic Chiasm
Where two optic nerves meet
Half the fibers from each eye cross
Where is the right eyes visual field represented?
The left hemisphere
Where is the left eyes visual field represented?
The right hemisphere
Geniculostriate Pathway
LGN –> Striate Cortex–> Visual Cortex
Pattern Analysis
Visual Form Agnosia
inability to recognize objects
symptom of damage to geniculostriate syste,
Tectopulvinar System
Detection and orientation of visual stimuli
Superior Colliculus–> Pulvinar–> Visual Cortex
Visual Ataxia
the inability to recognize where objects are located
Hemianopia
vision loss of the right vision field
Quadrantanopia
Vision loss in 1/4 of the vision field
Scotoma
a blind spot in the vision field
Dorsal Stream
Vision for action
Ventral Stream
Object perception and perceiving certain types of movements
Area V5
specialized to detect motion
Area V4
Area of color
What happens when V4 area is damaged?
People only see shades of grey and can’t recognize faces
Damage to Left OTG
Difficulty Reading
Can’t read
Unable to name colors
Damage to Right OTG
Difficulty recognizing peoples faces and identifying handwriting
Prosopagnosia
Facial recognition deficit
Apperceptive Agnosia
Failure of perception
Associative Agnosia
Failure to recognize an object
8th Cranial Nerve
Carries auditory and vestibular information
What is the range of human hearing?
-20-20,000 hz
Pinna
Found in the outer ear
catches waves of air pressure
Ossicles
Found in the middle ear
3 smallest bones of the human body
Attach the eardrum to the inner ear
Cochlea
Found in the inner ear
Contains hair cells
Hair cells
Auditory sensory receptors
Organ of Corti
part of the basilar membrane where hair cells are found
Where is the basilar membrane found?
In the cochlea
Where are high frequency sounds heard?
at the base of the basilar membrane
Where are low frequencies heard?
at the apex of the basilar membrane
Inner hair cells
Sensory cells
Outer hair cells
Amplifiers
What forms the lateral lemniscus?
the axons in the ventral cochlear nucleus
Primary Auditory Cortex
First cortical structure to process incoming auditory information
Vestibular System
Involved in balance, eye movement and body position in space
