Exam 2 Flashcards
Sensory Receptors
Specialized receptors that detect a particular category of physical events
Receptor Potential
A slow, graded electrical potential produced by a receptor cell in response to a physical stimulus
Eye Movements:
Vergence
Saccadic
Pursuit
Cooperative movement of eyes, like looking at nose
Rapid, jerky movement of eyes to maintain focus
Movement of eyes that allows for fluid following of motion
Ciliary Muscles
Control shape of eyes
Accommodation
Changes in thickness of lens, accomplished by ciliary muscles, that focus images of near or distant objects of the retina
Retina
Neural tissue and photo receptive cells located on inner surface of posterior portion of eye
Photoreceptors
Transduce photic energy into electrical potentials
Rod - low energy (b/w)
Cone - high energy, colour
Fovea
Region of retina that mediates most acute vision; contains only cones as photoreceptors; has low convergence because few photoreceptors on few ganglion cells. BUT periphery has high convergence since many photoreceptors on few ganglion cells
Bipolar cell
Bipolar neuron located in the middle layer of the retina, conveying information from the photoreceptors to ganglion cells
Ganglion Cells
Neuron in retina that receives visual information from bipolar cells; its axons give rise to the optic nerve
Horizontal Cell
Neuron in retina that interconnects adjacent photoreceptors and the outer processes of the bipolar cells
Amacrine cell
Neuron in retina that interconnects a jacket ganglion cells and the inner processes of the bipolar cells
Lamella
Layer of membrane containing photo pigments; found in rods an cones
Photo pigment
Protein dye bonded to retinal that is responsible for transduction of visual info
Opsin
Retinal
Class of protein that acts as a photo pigment
Chemical synthesized from vitamin A that acts as a photo pigment
Dorsal Lateral Geniculate Nucleus (LGN)
A group of cell bodies within the thalamus that receives input from the retina and projects to the primary visual cortex
Magnocellular Layer
One of inner two layers of neurons in dorsal lateral geniculate which transmits information necessary for the perception of form, movement, depth, and small differences in brightness
Parvocellular Layer
One of the outer four layers of neurons in the dorsal lateral geniculate, which transmit information necessary for perception of color and fine details.
Kiniocellular Sublayer
One of the sublayers of neurons in the dorsal LGN found ventral to each of the magnocellular and parvocellular layers; transmits information from short-wavelength (blue) cones to the primary visual cortex.
Optic Chiasm
A cross-shaped connection between the optic nerves, located below the base of the brain, just anterior to the pituitary gland.
Calcarine Fissure
A horizontal fissure on the inner surface of the posterior cerebral cortex; location of the primary visual cortex
Striate Cortex
The primary visual cortex
ON Cell
Fires when light is presented in ON center of receptive field and when light is removed from OFF surround of receptive field.
OFF Cell
Fires when light is presented in ON center of receptive field and when light is removed from OFF surround of receptive field.
Trichromatic Theory
Colors may be created by mixing various quantities of three colors.
Light waves not pigments.
Opponent Colour Theory
Red/Green, Yellow/Blue (Bluish green but not greenish red)
Protanopia
An inherited form of defective color vision in which red and green hues are confused; “red” cones are filled with “green” cone opsin
Deuteranopia
An inherited form of defective color vision in which red and green hues are confused; “green” cones are filled with “red” opsin
Tritanopia
An inherited form of defective color vision in which hues with short wavelengths are confused; “blue” cones are either lacking or faulty
Retinal Ganglion Cells
Opponent-Process Coding
Color Sensitive Ganglion Cells
—Red-Green
—Yellow-Blue
Striate Cortex
Has six principles layers
About 25% dedicated to fovea
Contralateral coding
Orientation Sensitivity
Idea that most neurons in the striate cortex are sensitive to the orientation of the stimulus.
Simple Cell
An orientation-sensitive neuron in the striate cortex whose receptive field is organized in an opponent fashion. On/off
Complex Cell
A neuron in the visual cortex that responds to the presence of a line segment with a particular orientation located within its receptive field, especially when the line moves perpendicularly to its orientation.
Hypercomplex Cell
A neuron in the visual cortex that responds to the presence of a line segment with a particular orientation that ends at a particular point within the cell’s receptive field
Sine-Wave Graphing
A series of straight parallel bands varying continuously in brightness according to a sine-wave function, along a line perpendicular to their lengths.
Spatial Frequency
The relative width of the bands in a sine-wave grating, measured in cycles per degree of visual angle
Retinal Disparity
The fact that points on objects located at different distances from the observer will fall on slightly different locations on the two retinas; provides the basis for stereopsis
Cytochrome Oxidase (CO) Blobs
The central region of a module of the primary visual cortex, revealed by a stain for cytochrome oxidase; contains wavelength-sensitive neurons.
Modules
Contain 100,000 to 1,000,000 neurons.
Striate cortex contains approximately 2,500 modules each with approximately 150,000 neurons.
Ocular Dominance
The extent to which a particular neuron receives more input from one eye than from the other.
Extrastriate Cortex
A region of visual association cortex; receives fibers from the striate cortex and from the superior colliculi and projects to the inferior temporal cortex;several regions, each contains one or more independent maps of the visual field. Each region responds to certain features of visual information, color, movement, etc
Dorsal Stream
A system of interconnected regions of visual cortex involved in the perception of spatial location, beginning with the striate cortex and ending with the posterior parietal cortex.
Ventral System
A system of interconnected regions of the visual cortex involved in the perception of form, beginning with the striate cortex and ending with the inferior temporal cortex
Visual Agnosia
Deficits in visual perception in the absence of blindness; caused by brain damage.
Prosopagnosia
Failure to recognize particular people by the sight of their faces.
Lateral Occipital Complex (LOC)
A region of the extrastriate cortex, involved in perception of objects other than peoples bodies and faces.
Fusiform Face Area
A region of the visual association cortex located in the inferior temporal lobe; involved in perception of faces and other complex objects that require expertise to recognize.
Extrastriate Body Area
A region of the visual association cortex located in the lateral occipitotemporal cortex; involved in perception of the human body and body parts other than faces
Parahippocampal Place Area
A region of limbic cortex on the medial temporal lobe; involved in perception of particular places (scenes)
Optic Flow
The complex motion of points in the visual field caused by relative movement between the observer and environment; provides information about the relative distance of objects from the observer and of the relative direction of movement
Akinetopsia
Inability to perceive movement because of damage to the V5 of visual association cortex
Intraparietal Sulcus
The end of thedorsal stream of the visual association cortex; involved in perception of location, visual attention, and control of eye and hand movements; AIP – visual control of grasping and manipulating hand movements.
LIP – visual attention and control of saccadic movements.
VIP – visual attention and control of saccadic movements, visual control of reaching and pointing.
CIP – perception of depth from stereopsis.
MIP – visual control of reaching and pointing.
Ossicles
Middle Ear Bones:
Malleus
Incus
Stapes
Cochlea
sensory organ for the auditory system.
Basilar Membrane
Hair Cells
Tectorial Membrane
Oval Window
Opening in the cochlea where the stapes is located
Tip Link
Elastic filament that attaches the tip of one cilium to the side of an adjacent one
Cochlear Nerve
Branch of the auditory nerve that transmits auditory information to the brain
Cochlear Nucleus
Nuclei in the medulla that receive auditory information.
Superior Olivary Complex
Nuclei in the medulla that receive auditory information from the cochlear nuclei
Lateral Lemniscus
band of fibers carrying auditory information through the medulla and pons
Medial Geniculate Nucleus
nucleus in the thalamus that relays the auditory information to the primary auditory cortex
Place Coding
Coding of frequencies by different locations on the basilar membrane
Rate Coding
Coding of frequencies by the rate of firing of neurons in the auditory system
Perception of Loudness
Achieved by alterations in the rate of firing of cochlear nerve axons
Perception of Timbre
Fundamental Frequency – lowest, and usually most intense, frequency of a complex sound.
Overtone – frequency of complex tones that occurs at multiples of the fundamental frequency
Look up and make cards about how the vestibular system works. Look back on Powerpoint 7
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Proprioception
Perception of body position and posture
Cutaneous Senses (5)
Pressure Vibration Heating Cooling Tissue Damage (pain)
Ruffini Corpuscles
vibration sensitive, large receptive fields, slow adapting
Pacinian Corpuscles
detects mechanical stimuli, especially vibrations, large receptive fields, fast adapting
Meissner’s Corpuscles
touch sensitive, small receptive fields, fast adapting
Merkel’s Disks
touch sensitive, small receptive fields, slow adapting
Touch
Involves Mechanoreceptors
Highly Localized
Temperature
Relative Perceptions
Involves Free Nerve Endings
Two Kinds of Thermal Receptors: Warmth & Coolness
Pain - The Three Types of Nocireceptors
High-threshold mechanoreceptors that respond to intense pressure, stretching, or pinching.
Free nerve endings that respond to extreme heat, acids, and presence of capsaicin.
TRPA1 receptors that are sensitive to pungent irritants found in mustard oil, wintergreen oil, horseradish, and garlic and to many environmental irritants. These chemicals produces inflammation
