Exam 3 (Unit 8, 9, 10, 11, 12) Flashcards
1
Q
Frequency
A
-Physical property of sound
- # of compressed or rarefied patches of air
that pass by your ears each second (Hz)
2
Q
What is a sound?
A
- Compression of particles in the air
- Crest= compressed air
- valley= rarefied air
3
Q
Amplitude
A
- Physcial property of sound
- Different in pressure between compressed and rarefied patches
- Increased amp, increased volume
4
Q
Complexity
A
- Physical properties of sound
- In nature, sounds are a mixture of frequencies, amplitudes, and their time courses
5
Q
Pitch
A
- Perceptual properties of sound
- Quality of a tone that is described as “high” or “low”
6
Q
Loudness
A
- Perceptual properties of sound
- Magnitude of auditory sensation, (decibels or dB)
7
Q
Timbre
A
- Perceptual properties of sound
- Differentiates two complex sounds of same fundamental pitch and same loudness
8
Q
Outer Ear
A
- Pinna= outer ridges
- Focuses sound to auditory canal
9
Q
Middle Ear
A
- Recieves airborne vibrations via large tympanic membrane (drum)
- Moves ossicles (stapes, bone) against small oval window
10
Q
Ossicles
A
- 3 tiny bones ands 2 muscles that move them
- Help to decrease amount of energy lost by sound waves going from air (external ear) to fluid (inner ear)
11
Q
Oval Window
A
-Stapes presses against the oval window, transduces vibrations from ossicles into waves of fluid
12
Q
Round Window
A
-Membrane permits movement of fluid
13
Q
Inner Ear
A
- Contains the cochlea
- a spiral bony canal which is filled with fluid (hearing), and the vestibular apparatus, which is similarly comprised
14
Q
Cochlea
A
- Within Inner ear
- Acts like a frequency analyzer
- Breaks complex tone into harmonics and responds to each harmonic
- Scalamedia= organ of corti, receptor of sound
- Basal membrane= bottom, tectorial membrane (top), hair cells (middle)
15
Q
Organ of Corti
A
- Hair cells in the organ of corti take the fluid movements of the vestibular and tympanic canals of the cochlea and transduce them into receptor potentials
- 1 Inner hair cell row= auditory perception (afferent/sensory)
- 3 outer hair call rows= amplifying and tuning organ of corti (efferent/motor)
- hair cell rows in line with each other
16
Q
Activation of Hair Cells
A
- Movement of endolymph in cochlea (wavelike)
- Deforms across the organ of corti
- Basal membrane pushes against techtorial membrane
17
Q
Transduction in audtion
A
- Tallest stereocillia bends toward smallest stereocillia–> hyperpolarization of cell
- Tallest bends away from smallest–> depolarized cell
- ***Due to tip links connecting stereocillia- no tension if bend towards, stretching if pulled away (opens K+ channels)
- Depolarization–> release fo Ca+–> hair cell releases glutamate (excites/depolarizes 1st order neuron)
18
Q
Volley Theory
A
- Lower frequencies
- Cochlea
- 1st order neuron will respond at rate which sound is moving (frequency)
- Activates hair cell when wave has a volley
19
Q
Phase Locking
A
- Volley theory
- a neuron that fires in time with each peak of a sound wave
20
Q
Place Theory
A
- Cochlea
- Encoding of sound frequency depends on where sound causes minimal displacement
- Apex tuned for low frequencies
- Base of basilar membrane tuned for high frequencies
- *Organ of corti is more loose as you head towards the apex
21
Q
Ascending Pathway for hearing
A
- Spiral ganglion
- Cochlear Nuclei
- Superior Olive
- Inferior colliculus
- Medial Geniculate Nucleus
- Primary Auditory Cortex
22
Q
Cochlear Nuclei
A
-Info integrated into left and right audio
23
Q
Superior Olive
A
-sound location
24
Q
Inferior Colliculus
A
- Auditory spatial map
- Important for reflexive responses to sound
25
Medial Geniculate Nucleus
- Relay center in hearing
| - thalamitic nucleaus
26
Primary Auditory Cortex
-Conscious awareness of sounds
27
Semicircular Canals
- Respond to angular acceleration of head (left, right, up, down, ear to sholder/ xyz)
- Cilia in bulb only activated by deformation in one direction
28
Otolith Organs
- Respond to linear acceleration of head
- Hair cells project into jello substance
- Crystals pull jello and deform cillia
* *crystals deform over time, falling/balance becomes an issue
29
Pupillary Light Reflex
1. Extraocular muscles orient visual field
2. Iris dialates pupil in response to light
3. Cornea focuses light through pupil
4. Ciliary muscles adjust lens shape to focus light on retina (accomodation)
5. Retina transduces image; inverted image
30
Visual Field
- The total amount of space that can be viewed by the retina when the eye is fixed ahead
- Right side of retina= left visual field
- Left side of retina= right visual field
- Upper visual field= bottom of retina
- Lower visual field= top of retina
* Image is inverted
31
Photoreceptors
- Respond to light (rods and cones)/ electromagnetic energy
- Influence membrane potential of the bipolar cells connected to them
- Outermost part of retina (deepest inside the head, farthest from front of eye)
* Depolarize in dark, hyperpolarize in light (less NTM in light)
32
Ganglion cells
- Fire action potenetials in response to light
- Impulses propogate along optic nerve to the rest of the brain
- Only source of output in the retina
- Innermost retinal layer= ganglion cell layer
- Types: Mtype and Ptype
33
Membrane potential at darkness
-Membrane potential in darkness= -30mV
34
Rod Photoreceptors
- More sensitive to light than cones
- Long, cylinderical outer segment (Lots of disks)
- Scotopic conditions= nighttime lighting, only rods contribute to vision
- Provide poor acuity
- No rods at center of fovea, only periphery
* Unable to distinguish color differences at night
35
Cone photoreceptors
- Short, tappered outer segment
- Less disks
- Excellent acuity
- Photopic lighting= daytime, cones do work
- Lots of cones at fovea, not as many at periphery
36
Photopigments
- Rods contain same photopigment (rhodopsin)
- Cones contain 3 diff types (red, blue, green), only responsible for 1 color
- Sensitive to diff wavelengths of light
37
Phototransduction in Rods and Cones in Dark conditions
-Opsin= GPCR--> Activates 2nd messenger--> opens Na+ channel--> depolarization--> release of glutamate-->depolarization of bipolar cell
38
Rhodopsin
-Absorption of light causes a change in confirmation of retinal--> activates opsin (bleeching)
39
Phototransduction in Light conditions
Opsin=GPCR-> 2nd mess.--> closing of Na+--> hyperpolarization--> stops glutamate release-->depolarization of bipolar cell
40
Ganglion Cell Receptive Fields
- Also have ON and OFF centers
- Fire APs, always fired regardless of light
- Enhance contrast and detect boarders
- Boarders interpreted by V1
41
ON ganglion cell receptive fields
- Lots of AP when light projected in center
| - Inhibited by more light in surround
42
OFF ganglion cell receptive fields
- Decrease APs when light shine at center
- Increase APs by more light in surround
- Will fire more if dark spot shined on center
* Dark at center= dep., surround=hyp.
43
M-type
-Large
-Larger receptive fields
Conduct APs more rapidly in optic nerve
-More sensitive to low contrast stimuli
-Stim of center= transient bust of APs
*Lack color opponency
44
P-type
- Small
- 90% of gang pop
- Respond to sustained discharge as long as stimlus is on
- Respond to only one color in RF center, cancelled by showing another color in surround
* *types: Red v green, blue v yellow
45
Parallel Processing in Vision
- Different visual atributes are processd simultaneously using distinct pathways
- Dorsal stream and ventral stream
46
Dorsal Stream vision
- Recives magnocellular inut (light v dark contrast and movement)
- V5
- Where/motion
47
Ventral Stream vision
- Parvocellular, FFA
| - What/objects
48
Striate Cortex
- V1
1. Orientaiton and movement=magnocellular
2. Form (spatial frequency)
3. Location (retinal disparity)
4. Color=parvocellular and koniocellular
- Retinotopic and columnar organization
49
Primary Visual Pathway
Optic nerve--> optic chiams (partial decussation)--> LGN--> primary visual cortex/striate cortex/V1
50
Other regions for senses
- Vision: Hypothalamus, Midbrain, Dorsal and ventral paths
- Taste: amygdala, hypothalamus
- Smell: amygdala, hippocampus
- Hearing: dorsa and ventral paths
- Vesibular/balance
- Touch:
51
Retinotopy
- the organization of the retina
- Neighboring cells in retina feed into neighboring places in their target structures
- reflected in the same organization in the LGN and V1
52
Optic Chiasm
-Partial decussation in vision
53
Visual Hemifield
- A half of your visual field (left or right)
- Left visual hemifield is viewed by right hemisphere
- Right visual hemifield viewed by left hemisphere
54
Area MT
- V5
- Dorsal stream
- Specialized processing of object motion
- Dyslexia article
55
Fusiform Face Area
- Ventral stream
| - Ability to recognize faces
56
Somatosensation
- Touch
- Temperature
- Pain
- Proprioception
57
Touch
- Contours
- Texture
- Hardness
- Sharpness
- Pressure
- Duration
58
Temperature
- Coolness
| - Warmth
59
Proprioception
- Body sensation
| - Where body and parts are as they move
60
Skin
- Largest sensory organ
- Type 1:Glabrous skin= finger tips, palms/soles, w/o hair
- High concentration of receptors
- Detect stimuli by contours, form texture
- Type 2: hairy skin
61
Mechanoreceptors
- Nerve terminals associated with cell structure
- Mediate: pressure, proprioception, hearing, balance pain
- Sense contact, pressure, stretching, vibration
1. Pacinian corpuscles
2. Ruffini's endings
3. Meissner's corpuscles
4. Merkel's disks
62
How Mechanoreceptors adapt to lasting stimuli
- Done at diff rates
* Rapid vs slow adaption
* Large vs small receptive field size
- Axons fire in response to change, stop firing when stim remains the same (due to connective tissue)
63
Rate coding
-As strength of stimuli increases, rate of AP firing incresses
64
Pain
- Perception of specific (harmful) stimuli
- Trama to tissue
- Extremes above qualities (pressure or temp, noxious chemicals)
65
Nociception
- Sensation of stimuli that lead to pain
- Free nerve endings not associated w/ other structures
- Respond to mechanical, thermal, and chemical stimuli
* **Ex: TRP cation channels
66
Why nociceptors act in unity
- Stimulation affects multiple receptors simultaneously
- Combined info leads to understanding/ ID of stimulus
- Putting pressure on injury bcuz input from mechanoreceptors can override pain signal by activating inhibitory neurons
67
Ascending pathway of touch
1. Sensory receptor
2. dorsal root
3. dorsal column nucleus
5. medial leminiscal pathway
6. VP Nucleus
7. primary sensory cortex
68
Somatotopy
- Column organization in S1
* Layers of slow adapting neurons and rapid adapting neurons
- Cortex organized for sensation
69
Tonotopy
- Specific sounds managed in auditory cortex
| - preserved from cochlea to cortex
70
Ascending pathway pain
1. Dorsal root
2. SC
3. VP and intralaminar
4. S1
71
Other regions for pain
- Insular cortex (unpleasantness/immediare emo consequecnes/pain intensity)
- Anterior cingulate cortex (unpleasantness/ immediate emo consequences)
* Further integration of sensory info, attention, storage of memories= prefrontal cortex
72
Characteristics of Sensory Systems
- Recieve physical stimulus
- Transduce the physical stimulus into an electrochemical signal
- Movement of a signal along sensory pathways from periphery to brain
- Form whole perceptions of objects out of many signals
73
Accesory stuctures
- Parts of the sensory systems that gather external stimulus energies and "create" the proxial stimulus which researches the sensory receptor cells
- Ear, skin, nose, tongue, eye
74
1st Order Neuron
- The first neuron in a sensory system
| - Sometimes, but not always, sensory receptor cell (hearing, taste= epithilial cell)
75
2nd Order Neuron
-Projection neuron that recieves information from first-order neuron and projects to 3rd order
76
Sensory Receptor Cells
- Specialized neuron or specialized epithelial (body tissue) cell that converts (transduces) physical energy into changes in membrane potential
- 4 classes:
1. Mechanoreceptors
2. Chemoreceptors
3. Thermoreceptors
4. Photoreceptors
77
Chemoreceptors
- Activated by chemical energy
| - Mediate: Taste, smell, pain
78
Thermoreceptors
- Acitvated by thermal energy
| - Mediate: temp, pain
79
Graded
-Amplitude varies w/ amp of stim or postsynaptic signal
80
Local/Passive
-Dies out w/ distance
81
How do we taste?
- Tasants
- Molecules disolve in saliva and bind to taste receptors on tongue
- Stimuli= bitter, sour, sweet, salty, umami, fatty (unknwon)
82
Taste Receptors
- Contained in taste buds w/ cilia projecting into folds of tongue around papillae
- Quick regeneration (10 days)
- Disolved molecules from saliva travel into fold to make contact w/ cilia
- Taste receptor cells synapse w/ bipolar neurons (1st order neurons)--> cranial
83
Taste Transduction
-Tastant binds to taste receptor (GPCR=sweet, umami, bitter or TRP=salty, sour--> depolarization--> release of ATP (sweet, umami, bitter) or 5-HT (salty, sour)-->depolarization of 1st order neuron
84
ATP as neurotransmitter
- ONLY IN TASTE
- Released from taste receptor cells via channels
- ATP receptors on taste neurons conduct signal
- Induces inhibitory signaling (neg feedback)
85
Gustatory/Taste Pathway
-Cranial nerves (9,10,7)-> brainstem->NTS->VPM thalamus-->primary gustatory cortex
86
Olfactory receptors
- Located in olfactory epithelium
- Odorants must dissolve into mucosa and bind to receptors in cilia
- Odorants= water soluble, low polarity, airborn, lipophilic properties
- 1st order, bipolar neurons
- 1 type of odorant receptor (GPCR) in cilia of olfactory cell
* **activate ion channls, initiate AP
87
How do we distinguish smells
- Odorants bind to specific combo of receptors
| - Can differentiate 10,000 odorants
88
Olfaction/ Smell pathway
-Receptor cell--> mitral cells--> glomeruli-->olfactory bulb--> piriform cortex
89
How is smell linked to emotional memory?
- Projections to amygdala and hippocampus
| - Smell can elecit decalartive memory
90
Types of coding
- Taste=rate coding
- Smell=population coding
- Sight=rate coding
- Hearing= place coding
- Balance
- Touch=rate coding
- Pain= rate coding
91
Type of receptor
- GPCR and TRP: Taste
- GPCR: Smell, Sight,
- Mechanoreceptor: Hearing, pain, touch
92
Touch Transduction
-touch--> mechanoreceptors opned by pressure on cell membrane, extracellular protein, or cytoskeletal protein--> Na+ and Ca2+ inside cell--> depolarization--> activation 1st order neuron
93
Decussation
- Taste and smell: None
- Optic chiasm: partial decussation for sight
- Pons= hearing
- Medulla= touch
- Spinal cord= pain
- Balance?
94
Transduction of Smell
1. Odorants bind to GPCR
2. Stim G protein
3. Activate adenlyl cyclase
4. form camp
5. camp binds to cyclic nucleotide gated ion channel
6. opens Na+ and Ca2+ goes in
7. opens cl- channels
8. depolarization
9. depol of 1st order neuron
