Extra (Final) Flashcards
(55 cards)
Far more of the human brain is dedicated to [blank] than any other sense
Vision
What lies in front of photoreceptor cells at the back of the eye?
Neurons (transparent, do not hinder the very light sensitive photoreceptor cells) which are insensitive to light
How does the visual system solve the blind spot problem?
The optic disk (blind spot) is in a different spot in each eye
Left of fovea in left eye, right of fovea in right eye
Where are rods most abundant?
Where are cones most abundant?
Rods more abundant outside the fovea
Fovea has only cones
Difference of rods and cones with respect to light-absorbing pigments
All rods have same pigments (419 nm [white])
Cones have one of three pigments
S cone = 419 nm [blue, short]
M cone = 531 nm [green, medium]
L cone = 559 nm [red, long]
(Four pigments altogether form the basis of our vision)
(Frequencies shown are of max. absorption)
Constancy vs sensitivity of perceiving colour from blue, red, and green cones
Three cones are evenly distributed (perceive colour fairly constant across the visual field)
Numbers of red and green cones roughly equal, but there are fewer blue cones (not as sensitive to wavelengths in blue part of visual spectrum)
What are photoreceptors connected to?
Two layers of retinal neurons
First layer (amacrine, bipolar, horizontal cells)
Second layer (retinal ganglion cells)
Cortical columns
Strips of occipital lobe (0.5 mm)
What is the occipital lobe divided into?
6 visual regions (V1, V2, V3, V3A, V4, V5)
- V1 = primary visual cortex (striate cortex)
- Rest = extrastriate (secondary visual) cortex
Each extrastriate (secondary visual) cortex processes specific features of visual information
Each occipital region has different cytoarchitecture and unique inputs/outputs (different function)
Compression waves of changing air pressure (sound waves) move through what?
Compressible media, air, water, ground, etc. but not through vacuum of outer space
Sounds perceived as high pitched have ____?
More wave frequencies
(i.e., more waves per second)
In humans, the evolution of sound-processing systems for both language and music was accompanied by what?
Enhancement of specialized corticol regions (especially in temporal lobe)
Humans have marked expansion of auditory areas
Inner hair cells in the organ of corti synapse with what?
Neighbouring bipolar cells (axons that form the auditory nerve)
Free nerve endings for pain
(Nociception)
Slow
Free nerve endings for temp.
(Nociception)
Slow
Meissner’s corpuscle (touch)
(Hapsis)
Rapid
Pacinian corpuscle (flutter)
(Hapsis)
Rapid
Ruffini corpuscle (indentation)
(Hapsis)
Slow
Merkel receptor (steady skin indentation)
(Hapsis)
Slow
Hair receptors (flutter or steady skin indentation)
(Hapsis)
Slow
Muscle spindles (muscle stretch)
(Proprioception)
Rapid
Golgi tendon organs (tendon stretch)
(Proprioception)
Rapid
Join receptors (joint movement)
(Proprioception)
Rapid
Auditory pathway from cochlea to primary auditory cortex
Cochlea
Superior olives (hindbrain)
Inferior colliculus (tectum, midbrain)
Medial geniculate nucleas (thalamus, diencephalon)
Primary auditory cortex
