Exam 2 Flashcards
Stages of brain development?
- Proliferation
- Migration
- Differentiation
- Myelination
- Synaptogenesis
What is Prolifeation?
- Production of New Cells
What is migration?
- Movement of Cells
What is differentiation?
- Change from stem cells or immature cells in to specifically
What is myelination?
- Development of myelin
What is synaptogenesis?
- Formation of Synapses
How do axons find their way to needed location?
- Repel and attration of Gradient of chemicals
What is Radial Migration?
- From the inside of the brain to the outside
What is tangentially Migration?
- Along the surface of the bain
What kinds of migration does axons perform?
- Radial
- Tangentially
- Both
What is Apoptosis?
- A preprogrammed mechanism of cell death
- Stops with Neural growth factor
What is Neural Growth Factor?
- chemical released by muscles or target cells that require synapses with a neuron’s axon
what is Fetal Alcohol syndrome?
- caused by drinking during pregnancy
-alcohol inhibited release glutamate and enhances GABA
Cause to much apoptosis
what is Plasticity?
The brains ability to reorganize itself by forming new neural connections throughoutlife
What is Congenitally Blind?
- Do people who are congenitally blind have a similar reorganization for their brain as the ferrets who’s brain were intentionally rewired`
What are blind people better then sighted people?
- Tactile Discrimination
Does Learning to Read Change your brain?
- Adults who learned to read had more gray matter in cerebral cortex and ticker corpus callosum
What does Musical Training do to your brain?
- One area of the right temporal cortex was 30% larger in musicians than non-musicians
- Recognize tonal changes faster
- Hand-control areas are thicker
What is Musical dystonia?
- The brain can’t distinguish sensations or motor commands for various fingers and so they move together when playing insterment
What is the Law of specific Nerve Energies?
The sensory experience of a stimulus depend on the nerve which is being excited and then on the stimulus itself
Who developed the Law of Specific Nerve Energies?
- Johannes Muller
Graded Potentials for the Law of SNE?
- Information is coded as the duration and amplitude of potentials being generated by stimulation
Action Potential for the Law of SNE?
- Information is coded as the rate and pattern of firing of action potentials being generated by stimulation
Parts of the Front of Eye?
- Cornea
- Pupil
- Iris
- Lens
- Ciliary Muscle
What does the Cornea do?
- Dome covering the pupil, protects the eye from debris, helps focus light
What does the pupil do?
- A hole that lets light into the eye
What does the Iris do?
- Colored area around the pupil, opens and closes the pupil
What does the lens do?
- Directly behind the pupil, changes shape to focus light
What does the Ciliary Muscle do?
- Controls the movement of the lens
How does the eye focus?
- Uses the lens and cornea
What is Hypermetropia?
- Far-sightedness
- eyeball is too short and point of focus is behind retina
What is myopia?
- Near-sightedness
- Eyeball is to long and point of focus is in front of retina
How many layers of the Retina are there?
- 5 layers
What are the layers of the Retina?
- Photoreceptors
- Bipolar Cells
- Horizontal cells
- Ganglion Cells
- Amacrine Cells
What do/are photoreceptors?
- Rods and cones
- Detect initial light stimulus
- Process color and Contrast
What are rods?
- Sensitive to light
- Larger and abundant
- Lots connected to 1 bipolar cell
- pigment not sensitive to wavelength of light
- Found in Periphery
- pigment regenerates in 30 min
What are cones?
- Les sensitive
- Small and less abundant
- less connected to 1 bipolar
- 3 types with differing sensitive to wavelength
- Concentrated in fovea
- Pigment regenerates in 30
What is the Fovea?
- Small area of the retina that is specialized for high acuity vision
Why is the Fovea better for high acuity vision?
- Photorecetprs are more densely packed
- 1:1 ratio between photoreceptor and ganglion cells
- absence of blood vessels and axons in ganglion cells
What characteristics do both cones and rods have?
- Contain light-sensitve chemicals called photo pigments
- Hyper-polarize in light
- Don’t fire action potential
- Synapses with bipolar cells
What are bipolar cells?
- Carry output from photoreceptors to ganglion cells
What are/do horizontal cells?
- Modulate connection between photoreceptors and bipolar cells
What are/do ganglion Cells?
- Generate action potentials that are carried to the brain
What are Amacrine Cells?
- Modulate connections between bipolar and ganglion cells
How do Ganglion Cells cause Hermann Grid illusion to work?
- Generate action potential that is sent to brain
- Center-surround receptive Fields
What is Center-surround receptive field
- Area in visual space that is responsible for the firing rate of a particular cell
What is lateral inhibition?
- Inhibition that spreads across a neural network
- Cones inhibiting cones or ganglions inhibiting ganglions
What is Trichromatic Theory?
- Theory of process of color
- 3 different types of cones which respond differently to different wavelengths of light
What is Opponent-Processing Theory?
- Three types of color receptors each responding to a pair of colors, and being excited by one of the pair and inhibited by the other
- Red-green
- Blue-Yellow
- Black-White
What theory does cones follow?
- Trichromatic Theory
What theory does ganglion Cells fallow?
- Opponent-processing theory
What are the two pathways leaving the retina?
- Collicular Pathway
- Geniculate-striate Pathway
What is the Collicular Pathway?
- Involved in determining eye movements
- Maybe involved in Blindsight
What is Geniculate-Striate Pathway?
- From the retina, information is sent to the Lateral Geniculate Nucleus contralateral to the visual field and then to the primary visual cortex
What types of cells are in the Primary Visual Cortex?
- Simple Cells
- Complex Cells
- Hyper Complex Cells
What do simple Visual Cells do
- increase their firing rate in response to bars in a particular location at a particular orientation
What do complex visual cells do?
- Increase their firing rate in response to bars at a particular orientation, in a number of locations and most strongly to those in motion
What do Hyper complex cells do?
- similar to complex cells but firing rate is effected by the length of bar as well
How are the Columns organized in the V1 Visual system?
- Cells that have similar function are columned together
- Cells in column may respond to stimuli at same location, orientation or visual field
What is the “what” and “Where” Experiment
- Object Recognition
- Spatial Task
What is the object recognition task part of the What and Where experiment
- Two different shapes and monkey were to pick which shape needed from the two
What is the spatial Task par of the What and Where Experiment?
- Find where the shape is at compared to the monkey
What did the What and where experiment concluded?
- The ventral stream is important for object recognition but not spatial processing
What pathway does color perception use?
- Ventral pathway
- V4
What can damage to the V4 result in?
- Loss of Color Constancy
- Cerebral achromatopsia
What is the loss of Color Constancy entail
- Damage to V4
- The ability to detect the color of an object under various lighting conditions
What is Cerebral Achromatopsia entail?
- Cortical Color Blindness
- Damage to V4
What pathway does motion Perception use?
- DOrsal Pathway
- V5
How does motion move along the Pathway?
- MT Cells are celective to objects moving in particular direction at particular speed
- Respond to motion in all three dimensions
What does damage to V5 area cause?
- Akinetopsia
What is Akinetopsia?
- damage to V5
- Visual deficit where the patient can recognize objects but can’t decent whether they are moving or what direction/speed
What pathways does object recognition use?
- V1 and some V2
- V2 used in more complex stimuli
What does damage to V1 and V2 area cause
- Agnosia
What is Agnosia
- Damage to V1 and V2
- Deficit were patient cannot recognize objects even though visual acuity is intact
What does facial recognition use?
- Fusiform Gyrus
What does damage to Fusiform Gyrus cause?
- Prosopagnosia
What is Prosopagnosia?
- Deficit where patient can’t recognize faces even though visual acuity and ability to recognize objects remains
What is sound?
- Pressur changes in a medium that can be detected by auditory sense organs
What is Amplitude?
- DIfference between atmospheric pressure and the maximum pressure exerted by the wave
- Psych correlates to loudness
- Measured in decibles
What is frequency?
- Number of times in a given period that the wave repeated itself
- measured in Hertz
- human rand is 20 Hz to 20000 Hz
What are the layers of the ear?
- Outer
- Middle
- Inner
What doe the Outer ear consist of?
- Pinna
- Auditory Canal
- Tympanic Membrane
What does the Pinna do?
- Outer ear
- Amplify and Localize sounds
What does the Auditory Canal do?
- Tunnel leading from pinna to the tympanic membrane
- Outer ear
What does the Tympanic Membrane do?
- Vibrates in response to pressure changes in the atmosphere
- Outer ear
What does the middle ear consist of?
- Ossicles
What is the Ossicles
- Middle ear
- Bones that amplify and transmit vibrations from ear drum to oval window
- Hammer, Anvil and Stirrup
What does the Inner ear consist of?
- Oval WIndow
- Cochlea
What does the Oval WIndow do?
- Transmits vibrations from Ossicles to cochlea
What is the Cochlea?
- Inner Ear
- Fluid-filled snail-shaped organ containing the hair cells
What are the types of Tunnles in the Cochlea?
- Scala Vestibuli
- Scala Media
- Scala Tympani
What is the basilar membrane function?
- Separates the scala tympani and scala media
How does the Cochlea react to sound?
- Vibrations reach cochlea , fluid inside moves displacing hair cells, mechanically opening ion channels in membrane of hair cells, changing the graded potential of the hair cells, sending signals to neurons
What is the Place theory of Pitch Perception?
- Each location of the basilar membrane is activated by one specific sound frequency
- Pitch is determined by which hair is activated
What is the evidence for the place theory?
- Relationship between frequency of sound and are of greatest activation on basilar membrane
What is the Frequency Theory of Pitch Perception?
- The basilar membrane vibrates in synchronize with frequency of sound wave
- the rate of fire of the hair cells determines pitch
What is Volley Principle?
- part of frequency Theory
- Several neurons work together, firing in phase with the sound wave but out of phase with one another, to code the frequency of the sound
When is the Place theory of pitch perception correct
- Up to 100Hz membrane vibrates in sync
When is the Frequency theory of pitch perception correct?
- Between 100 and 4000 Hz basilar membrane follow volley principle
What is amusia?
- Pitch disorder
- Impaired perception
- Difficulty detecting change in pitch, melodies or out of pitch music and singing
What is Absolute Pitch?
- pitch disorder
- Ability to hear a note and identify it
- genetic component but require extensive musical training
What are the types of sound location?
- Interaural Intensity Difference
- Interaural time difference
- Phase difference
What is Interaural Intensity difference?
- A sound will be slightly louder in the ear closest to the sound then in the other
What is Interaural Time Difference
- A sound will be heard in the ear closest to the sound slightly sooner then the other
What is the Medial Superior Olive?
- cluster of neurons in the medulla that is likely involved in determining the location of the origin of sound
What is the Phase difference?
- Depending on the size of the ear, frequency of the sound and direction, sound waves can be in phase or out of phase between two ears
What is Vestibular Sensation?
- made up of vestibular organs located inside inner ear
Whar are the types of Vestibular sensations?
- Saccule and Utricle
- Semicircular Canals
What are Saccule and Utricle?
- part of the vestibular sensation
- Jelly filled sacks lined with hair cells
- Detech head tilt and linear acceleration/deceleration
What are the semicircular canals?
- Fluid filled tubes lined with hair cells in a semicircular shape, perpendicular to one another
- Detect head tilts in a particular direction
- Fluid goes in opposite direction of tilt
What is Somoatosensation?
- THe sensation of the body and its movement
- Touch, deep pressure, cold, warm, pain, itch, movement of joints
What effects somatosensation receptors?
- Axon Diameter
- Conduction Velocity
- Receptive Field Size
- type of Encapsulation
- Adaptation Rate
How does Conduction Velocity effect somatosensation receptors?
- Affected by axon diameter and myelination
How does pressure effect somatosensation receptors
- Activated receptors have very thick myelinated axons with fast conduction Velocities
- Merkel Disk
- Meissner Corpuscles
- Paciniam Corpuscles
What are Merkel Disks receptors?
- Responsible for detecting form and texture
- Slow at adapting
- Very small receptive Fields
What are meissner Corpuscles receptors?
- Responsible for grip control and detecting motion across the skin
- Plate like structure
- Rapid adapting
- large receptive field
What are paciniam Corpuscles Receptors?
- Responsible for detecting distant vibrations or sudden pressure on the skin
- Onion like layers
- rapid adapting
- largest receptive field (worst spatial resolution)
How does pain effect somatosensation receptors?
- Activation of Nocieptors
- thin axons with slower conduction velocity and free nerve ending
What are the types of rectors that pain effect?
- slow pain receptors
- Fast pain receptors
What are slow pain receptors?
- Respond to long-lasting pain
- unmyelinated
What are fast pain receptors?
- Respond to sharp fast pain
- Myelinated
What drugs relieving pain?
- Opioids and Endorphins
Cannabinoids
Capsaicin
How does Opoids and Endorphins Effect pain receptors?
- Block release of substance P in spinal cord and midbrain
- Only effect slow pain receptors
How does Cannabinoids effect pain receptors?
- Block pain in the PNS likely by inhibiting the inflammatory response
may also activate endorphin system
How capsaicin effect pain receptors?
- Depletes neurons of substance P
- larger does damage pain receptors
- Rubbed on sore area to relieve pain
What are some diseases associated with pain reception?
- Congenital Analgesia
What is Congenital Analgesia?
- abnormalities in nociceptors that lead to the inability to detect pain
What Does itch do to somatosensation receptors
- Sensation that is completely separate from touch of pain but similar
- Slow conducting
- free nerve cells
- Response to irritating chemicals and tissue
How does Proprioception effect somatosensation receptors?
- The sense of position of the body parts relative to one another and of their movements and exertion
What are muscle Spindles
- Part of Proprioception
- Receptors
- Thickest and most myelinated
What is group 1 of proprioception?
- Respond to muscle length
What is group 2 of proprioception?
- Respond to constant muscle length
What is Dermatome?
- Area of skin that sends sensory information to one single spinal nerve
What does olfaction influence?
- Social interaction, memory, reproduction, defensive response and feeding
Parts of olfaction system?
- Olfactory epithelium
- Olfactory Receptors
What does the olfactory epithelium do?
- Specialized layer of tissue lining the roof of the nasal cavity where recptors are
What do olfactory receptors do?
- Activated by sapecific odorants
What are cilia in olfactory system?
- Threadlike dendrites that extend into the muccous of the nasal passage
Hoe are the neurons in the olfactory?
- Thin, unmyelinated axons
- mostly metabotropic channels
How do the metabotropic channels effects the olfactory reception?
- Amplification of response so we can detect very small concentrations of odors
- allow smells to linger for extended periods
How is the olfactory system different between people?
- Decrease with age
- women more sensitive (child bearing years)
What is the Vomeronasal organ?
- Detect pheromones
- Separate but close to olfactory bulb
- Detects each pheromone in small concentration
- responds continuously to same stimulus
How does Taste result from?
- Stimulation of tste receptors located in taste buds
What do Pillae do?
- Part of Taste reception
- Area of tongue, palate, pharynx and upper esophagus that contains taste buds
- Mostly found along edge of tongue
What are the types of receptors for taste?
- Sweet
- Sour
- bitter
- Salty
- Umami
What type of receptor responds to sucralose?
Sweet
What type of receptor responds to acids?
- sour
What type of receptor responds to alkaloid substance?
- Bitter
What type of receptor responds to inorganic molecules that arn’t acids or alkaloids?
- Salty
What type of receptor responds to MSG
- Umami
How do taste receptors pass along messages?
- Synapse the next cell in the system
- 3 nerves
What is the Nucleus of the Tractus Solitarius?
- Information goes in the medulla to the pons, later hypothalamus, amygdala, thalamus and two area of cerebral cortex
What does the Primary mortor cortex control for tase?
- Muscle of tongue
What chemicals effect taste?
- Sodium lauryl sulfate
- Monosodium Glutamate
- Gymnema Sylvestre
- miracle Fruit
How does Sodium Lauryl Sulfate effect taste?
- intensifies bitter tastes and weakens sweet
How does monosodium glutamate effect taste?
- Increase sensitivity to salty and sweet tastes
How does Gymnema Sylvestre effect taste?
- Plant that maeks sweet foods taste bitter or salty
How does Miracle fruit effect taste?
- Makes sour foods taste sweet
What are Trigeminal Chemorectpors?
- Devoted to detecting irritating compound in mouth nose on face or in eye
What is flavor dependent on?
- Smell and taste
