Cognitive/Motor Flashcards
Large RFs, spatial features and motion.
Primary visual cortex
Small RFs, simple image features such as oriented line segments.
Parietal visual stream
Large RFs, complex image features
Temporal visual stream
visual and other sensory modalities are combined
Polymodal
Object recognition in the temporal lobe
Faces
The pupillary reflex of light in one eye
both pupils constrict
Frequency
Number of cycles per second = pitch (hertz)
loudness is determined on the wave by
Amplitude
Decibels
sound pressure/reference pressure
Whisper occurs at what dB
0-20
Conversation occurs at what dB
20-40
Heavy Traffic occurs at what dB
40-60
Live Rock occurs at what dB
80-100
Discomfort occurs at what dB
100-120
Pain occurs at what dB
140-160
The three layers on the normal audibility curve
Threshold, damage threshold, and pain
damage threshold
90 dB
How does maximum listening time per day change with volume level?
As volume increases, the listening time significantly decreases
Presbycusis
Progressive, bilateral hearing loss with increasing age, mainly for frequencies > 1,000 Hz
Where basilar membrane motion is converted into neuronal activity
the organ of corti
Deflection of basilar membrane produces
shearing of hair cell stereocelia
Outer hair cell “electromotility”
- Shortens when
- Lengthened when
- Shorten when depolarized
- Lengthened when hyperpolarize
Are used to evaluate hearing in newborns
Otoacoustic emissions
Hair cells contain what type of receptor
Hair cells contain mechanoreceptors
What connects each stereocilia?
Tip links
Tip links
gate ion channels in the stereocilia at the top of the hair cells
Mechano-transduction at tip link activates
activates afferent neurons
Ringing in your ears
Tinnitus
Two types of tinnitus
Transient and Chronic
Transient tinnitus
(< 24 hours)
- Usually due to loud noise.
- Excessive mechanical stress of stereocilia. - Tip-links are thought to break, but
eventually grow back (ringing stops).
Chronic tinnitus
- Many causes, but predominately loud noise. - Origin can be either inner ear, nerve or
central pathways. - Impacts quality of life (does not stop
Visual transduction
Photons: high energy but hard to catch (~100X106 photoreceptors)
Trillions of opsin molecules
Slow: G-protein cascade
Amplification: one photon closes many ion channels
Auditory transduction
Sound waves: low energy but all around (~15,000 hair cells)
Several hundred thousand tip links
Fast: direct channel activation
No amplification of the transduction
Central auditory pathways
Primary auditory cortex Thalamus Midbrain Medulla 8th cranial nerve (vestibular and auditory)
Cochlear Implant is required due to
Hair cell loss due to ageing, loud sounds, ototoxic drugs:
Cochlear Implant steps
1) Implanted through round window
2) Electrode placed in scala tympani
3) Electrodes are spaced along the cochlear spiral to stimulate groups of afferent fibers that respond to different frequencies.
Generally ~12 electrodes.
Why when the head rotates; eyes rotate in opposite direction and gaze does not change
Vestibular ocular reflex
vestibular system controls
includes the parts of the inner ear and brain that process the sensory information involved with controlling balance and eye movements.
One key similarity between the auditory and vestibular system
Tip links gate ion channels in the stereocilia
Organization of semicircular canals at rest vs rotation of the head
stereocilia bend
Utricle and saccule detect
linear acceleration
- Utricle: horizontal
- saccule: vertical
How many taste buds do you have?
about 10000
5 types of taste
Umani, Salty, Sour, Bitter, Sweet
Central taste pathways goes through …..
Cranial Nerves
Medulla
Thalamus
Ipsilatory gustatory cortex
Olfaction
Smell
Salty channels
sodium moving through channel
Sour channels
Sodium and hydrogen move through channel then potassium is pumped back across against hydrogen
Bitter channels
Bitter blocks potassium channels
various G-protein cascades
Sweet channels
G-protein cascade
Umani channels
Glutamate receptors
G protein cascade
Olfactory signal transduction
Ordorant binding to orderant receptor
G protien activation
Opening of ion channel
How many orderant receptors?
1000
Central olfactory pathways
Olfactory bulb to Olfactory tract to nerve to limbic system
Consciousness is measured by
behavior and brain activity
State of consciousness
level of arousal (awake, asleep, etc.)
thoughts, feelings, desires, ideas, etc
Conscious experience
The electroencephalograph (EEG)
Mainly measures activity of neurons located near the scalp in the
gray matter of the cortex.
EEG Frequency
is related to
levels of responsiveness.
EEG amplitude
is related to synchronous neural activity
EEGs reflect
mental states
relaxed with eyes closed
slow frequencies
Alpha rhythm
alert
fast frequencies
Beta rhythm
Awake rhythm amplitude and frequency
Low amplitude and high frequencies
How many stages of NREM
4
NREM
slow wave sleep
REM
paradoxical sleep
As you go from stage 1 to 4 what changes?
amplitude increases
frequency decreases
How long does it take for stages 1-4 of NREM to occur?
30-45 minutes
REM sleep rhythm
low amplitude
high frequencies
Sleep apnea
sudden reduction in respiration
At REM what happens to eye and neck movements
Increased eye movement
Increased inhibition of skeletal muscle (low muscle tone, but twitching can occur)
At REM what happens to the heart and respiration rate?
Increased heart rate and respiration
Regulating States of consciousness involves two parts
Brainstem nuclei that are part of the reticular activating system
- Hypothalamus with circadian and homeostatic centres
what occurs when waking in norepinephrine, serotonin and acetylcholine levels?
increased norepinephrine and serotonin
decreased acetylcholine
State when aminergic neurons are active
waking (reticular activating system)
what occurs to go into REM sleep in norepinephrine, serotonin and acetylcholine levels?
decreased norepinephrine and serotonin
increased acetylcholine
State when cholinergic neurons are active
REM sleep
the reticular activating system is for
Waking or REM sleep
the hypothalamus is for
NREM sleep or waking
What happens to GABA, histamine, and activation of the thalamus and cortex levels during waking?
decreased GABA
increased histamine
increased activation of the thalamus and cortex
increased histamine would result in
waking
Increased inhibition would result in
NREM sleep
What happens to GABA, histamine, and activation of the thalamus and cortex levels for NREM sleep?
increased GABA
decreased histamine
decreased activation of the thalamus and cortex
Motivation
produce goal-directed behavior
Emotions
accompany our conscious experiences
Mesolimbic dopamine pathway
Reward pathway
the primary neurotransmitter in the reward pathway
dopamine
Self stimulation experiments
Continuous activation of reward related areas of the brain.
What pathway involves the Prefrontal cortex, midbrain, locus cereleus in the reticular activating system
Mesolimbic dopamine pathway
Limbic system
Emotions system
Limbic system parts of the brain
Olfactory bulb
Amygdala
Hippocampus
Hippocampus
related to memory
Schizophrenia
diverse set of problems in basic cognitive processing. Wide range of symptoms including hallucinations and delusions. Affects one out of 100 people.
Reducing the effects of dopamine can improve symptoms of
Schizophrenia
decreased activity in the anterior limbic system results in
Depression
increase the levels of serotonin and
norepinephrine in the extracellular space around synapses is a treatments of
depression
Bipolar disorder
swings between mania and depression.
Treatments that include lithium that reduces certain synaptic signalling pathways are for
Bipolar disorder
Central olfactory pathways leads to the ____ system by ____
limbic system by the olfactory bulb/nerve
What does the odorant bind to and where?
odorant receptors in the cilia
What does the odorant binding activate?
G-protien and opens the ion channels
Consolidation
short-term to long-term
Best way for consolidation to occur
sleep
Learning and memory occurs in the
Hippocampus
Conscious experiences that can be put into words
Declarative memory
Memory type: Skilled behaviour
Procedural memory
Short term declarative memory occurs in what parts of the brain?
Hippocampus and other temporal lobe structures.
T/F: Long term declarative memory occurs in many areas of association cortex
T
T/F: Short term procedural memory occurs only in the hippocampus
F it is widely distributed
Long term procedural memory stored
in Basal nuclei, premotor cortex, Cerebellum
Language hemisphere
Left
Aphasia
language deficit
Articulation of language occurs in the
Broca’s area
Where does comprehension of language occur?
Wernicke’s area
Neglecting part of the body or space, which can also impair drawing ability is due to damage in the
parietal lobe
Motor behaviour can be
Purposeful or goal directed
Two specific types of motor behaviour
1) Voluntary 2) Reflexive
Agonist
muscle contracts
Antagonist
muscle relaxes
Agonist and Antagonist Extension muscles
Agonist: Extensor muscle contracts
Antagonist: Flexor muscle relaxes
Agonist and Antagonist Flexion muscles
Antagonist: Extensor muscle relaxes
Agonist: Flexor muscle contracts
Decrease the angle around the joint
Flexion
Increase the angle around the joint
Extension
Limb position is maintained by a
balance of flexor and extensor muscle tension
muscle activation and relaxation of flexor and extensor is
coordinated
Motor neurons are (excitatory/inhibitory/both)
Only excitatory (ACh)
Alpha motor neurons
innervate skeletal (extrafusal) muscle
Gamma motor neurons
innervate muscle spindle (intrafusal)
Motor neurons receives input mostly from
interneurons
Cell bodies of motor neurons are in
ventral horn of spinal cord (spinal nerves) or brain stem (cranial nerves)
Spinal interneurons: descending pathways control
Voluntary movements
Spinal interneurons: other spinal levels
Coordinates complex movements
Spinal interneurons: joint receptor
Proprioceptive feedback
Spinal interneurons: skin receptor
Pain
Spinal interneurons: tendon receptor
Tension
monitoring
Spinal interneurons: muscle receptor (from antagonistic muscle)
Length monitoring
Ascending sensory information moves through
dorsal columns
Motor neuron is in the (dorsal/ventral) horn
ventral horn
Motor efferent in the (dorsal/ventral) root
in ventral root
What protects limbs from injury?
Withdrawal reflex
What reflex controls muscle length?
Stretch reflex
Two types of stretch reflex
monosynaptic, polysynaptic
Inverse stretch reflex
controls muscle tension
T/F: Spinal reflexes can be overridden and modified
Most spinal reflexes can be overridden
Flexion withdrawal reflex on the ipsilateral
- inhibition of
- excitation of
- Inhibition of motor neurons innervating the ipsilateral extensor
- Excitation of motor neurons innervating the ipsilateral flexor
Flexion withdrawal reflex on the contralateral
- inhibition of
- excitation of
- Inhibition of motor neurons innervating the contralateral flexor
- Excitation of motor neurons innervating the contralateral extensor
Magnitude of withdrawal reflex depends on the
magnitude of pain stimulus
In the withdrawal reflex, limb withdrawal persists even after removal of the painful stimulus because of
Feedback loops in the spinal cord
Afterdischarge
Response maintained after stimulus termination (spinal feedback loops)
Irradiation
distance of limb withdrawal
Increase in rate and magnitude of withdrawal response with increased stimulus strength (recruitment of interneurons).
ipsilateral properties of withdrawal reflex:
- contraction of
- relaxation of
Flexor muscle contraction
Extensor muscle relaxation
Contralateral properties of withdrawal reflex:
- contraction of
- relaxation of
Extensor muscle contraction
Flexor muscle relaxation
Interneurons between sensory input and motor output
Polysynaptic
Monosynaptic stretch reflex
knee jerk
Knee jerk is due to excitation/inhibition of motor neurons in the ipsilateral extensor
excitation
Knee jerk is due to excitation/inhibition of motor neurons in the ipsilateral flexor
inhibition
Muscle spindle is in series/parallel with extrafusal muscle
parallel
Extrafusal muscle fiber is activated by
alpha motor neurons
Intrafusal muscle fiber is activated by
gamma motor neurons
2 types of muscle spindles afferents
la primary
la secondary
nuclear bag fibers are _____ afferents
la primary
nuclear chain fibers are ______ afferents
lI secondary
la ______ causes dynamic changes in muscle length (and some static length)
Ia primary
signal static muscle length
II secondary
What happens to muscle spindles when the spindle collapses in voluntary flexion?
lose sensitivity
Muscles in extension are lengthened/contracted
lengthen
Muscles in voluntary flexion are lengthened/shortened
Muscles are shorten
Extension/Voluntary flexion: Increase in muscle spindle afferent activity
Extension
Extension/Voluntary flexion: Muscle spindle collapses (sensitivity is reduced)
Voluntary flexion
Extension/Voluntary flexion: intrafusal fibers contract and muscle spindle is stretched
Voluntary flexion
How is spindle sensitivity maintained?
Intrafusal fibers contract and muscle spindle is stretched
Alpha-gamma act in a coactivation/cocontraction
coactivation
Change in length activates
muscle spindle
Properties of stretch reflex (3)
Resists changes in muscle length
Mono- and polysynaptic components.
Feedback from muscle spindles.
Properties of muscle spindles (3)
1) Reports muscle length.
2) In parallel with extrafusal muscle fibers (does not contribute to the force of muscle contraction).
3) Alpha-gamma coactivation.
Detects changes in muscle length and some static length (nuclear bag fibers)
Ia primary
Detects static length (nuclear chain fibers).
II secondary
Maintain muscle spindle sensitivity.
Intrafusal fibers
Golgi tendon organ reports to
tension
Active contraction of a muscle produces more ______ than ______
(stretching, tension)
tension than stretching
Golgi tendon is in (series/parallel) with the muscle
series
Golgi tendon organ structure
Capsule
Ib afferent
Free nerve ending
collagen fibers
Number of golgi tendon afferents
1: lb afferent
Golgi tendon organ reflex
(inverse stretch)
Properties of Golgi tendon organ
- Reports ____
- in _____ with extrafusal muscle fibers.
- ___ afferents
- Underlies ______ stretch reflex
1) Reports muscle tension.
2) In series with extrafusal muscle fibers.
3) Ib afferents.
4) Underlies inverse stretch reflex (polysynaptic).
Reports muscle tension.
Golgi tendon organ
In series with extrafusal muscle fibers.
Golgi tendon organ
Ib afferents.
Golgi tendon orga
Underlies inverse stretch reflex (polysynaptic).
Golgi tendon organ
Golgi tendon organ reflex:
increased/decreased afferent activity from Golgi tendon organ
increased
Golgi tendon organ reflex:
increased/decreased tension in the extensor muscle
increased
Golgi tendon organ reflex:
Inhibition/Excitation of motor neurons innervating the ipsilateral extensor
Inhibition
Golgi tendon organ reflex:
Inhibition/Excitation of motor neurons innervating the ipsilateral flexor
Excitation
High, Middle, Low level:
Consciously initiate movement
High
High, Middle, Low level:
Executes the individual muscle contractions.
Middle
High, Middle, Low level:
Makes corrections based on sensory information.
Middle
High, Middle, Low level:
Sensorimotor cortex
Middle level
High, Middle, Low level:
Basal nuclei
Middle level
High, Middle, Low level:
Thalamus
Middle level
High, Middle, Low level:
Brainstem
Middle level
High, Middle, Low level:
Cerbellum
Middle level
High, Middle, Low level:
Brainstem and spinal cord
Low level (local)
T/F: Voluntary movements do not have an “involuntary” component
F: Voluntary movements have an “involuntary” component
Voluntary control of movement is initiated in the ______
frontal lobe
Organization of primary motor cortex: top to bottom
legs
arms
head
Size of body structures in primary motor cortex is proportional to the (2)
- number of neurons dedicated to their motor control
- degree of skill required to operate that area of the body
relationship between select muscle groups and the body areas they control
Systematic
Corticospinal
skilled movements
Extrapyramidal
trunk & posture
Corticospinal is from ________ to ____ and ______
from sensorimotor cortex to brainstem and spinal cord
Does Corticospinal cross the medulla
Yes
(Corticospinal/Extrapyramidal)
Originates in primary motor cortex (precentral gyrus).
Corticospinal
(Corticospinal/Extrapyramidal)
Compact, discrete fiber tract direct to spinal cord.
Corticospinal
(Corticospinal/Extrapyramidal)
Crossed: Controls contralateral muscles.
Corticospinal
(Corticospinal/Extrapyramidal)
Extremities: Predominantly hands and feet.
Corticospinal
(Corticospinal/Extrapyramidal)
Controls skilled voluntary movements.
Corticospinal
(Corticospinal/Extrapyramidal)
Originates from neurons in brainstem.
Extrapyramidal
(Corticospinal/Extrapyramidal)
Diffused and indirect: Several descending tracts via the brainstem.
Extrapyramidal
(Corticospinal/Extrapyramidal)
Crossed and uncrossed.
Extrapyramidal
(Corticospinal/Extrapyramidal)
Trunk and postural muscles.
Extrapyramidal
(Corticospinal/Extrapyramidal)
Controls upright posture, balance, and walking.
Extrapyramidal
Resistance of skeletal muscle to stretch.
Muscle tone
Muscle tone of Normal subject
Slight and uniform
Hypertonia
Abnormally high muscle tone.
Hypotonia
Abnormally low muscle tone.
Spasticity
Overactive motor reflexes.
Rigidity
Constant muscle contraction.
Atrophy
Loss of muscle mass
Helps to determine the specific sequence of movements needed to accomplish a desired action.
Basal nuclei
One of the most common movement disorders.
Parkinson disease
Reduced dopamine input to the basal nuclei.
Parkinson disease
Akinesia
Reduced movements
Bradykinesia
Slow movements
What is in contrast with cerebellar deficits?
Resting tremor
Treatment for Parkinson disease
increasing dopamine concentrations in the brain
One of the most common movement disorders.
Parkinson disease
Name the disease that causes this symptom:
Reduced dopamine input to the basal nuclei.
Parkinson disease
Name the disease that causes this symptom:
Akinesia
Parkinson disease
Name the disease that causes this symptom:
Bradykinesia
Parkinson disease
Name the disease that causes this symptom:
Muscular rigidity
Parkinson disease
Name the disease that causes this symptom:
Resting tremor
Parkinson disease
Treatment for Parkinson disease
increasing dopamine concentrations in the brain
Name the disease that causes this symptom:
Genetic mutation that causes widespread loss of neurons in the brain.
Huntington disease
Name the disease:
Shows up later in life and causes neurons in the basal nuclei to be referentially lost
Huntington disease
Name the disease that causes this symptom:
hyperkinesis
Huntington disease
Name the disease that causes this symptom:
Choreiform movements
Huntington disease
Hyperkinetic disorder
excessive motor movements
Choreiform movements
jerky, random involuntary movements of limbs and face
What is deep brain stimulation used for?
To treat Parkinson disease
two places of deep brain stimulation
globus pallidus and subthalamic nucleus
Part of brain that controls movement timing, planning, and error correction. Learning new motor skills.
Cerebellum
Contains almost half of the brain’s neurons
Cerebellum
What type of information does the cerebellum receive and integrate?
Receives sensory information: vestibular, visual, auditory, somatosensory, proprioceptive.
Name the disease that causes this symptom:
Asynergia
Cerebellar degeneration (deficits)
Name the disease that causes this symptom:
Dysmetria
Cerebellar degeneration (deficits)
Name the disease that causes this symptom:
Ataxia
Cerebellar degeneration (deficits)
Name the disease that causes this symptom:
Intention tremor
Cerebellar degeneration (deficits)
Name the disease that causes this symptom:
No paralysis or weakness
Cerebellar degeneration (deficits)
Asynergia
Smooth movements are subdivided into their separate components.
Dysmetria
Unable to target movements correctly “past pointing”.
Ataxia
Incoordination of muscles groups (awkward gate).
Intention tremor
During voluntary movements.
otolith
sense gravity and linear acceleration such as from due to initiation of movement in a straight line
Stereocilia bend relative to
Otoliths which lags behind
Auditory or Visual transduction:
Sound waves: low energy but all around (~15,000 hair cells)
Auditory
Auditory or Visual transduction:
Several hundred thousand tip links
Auditory
Auditory or Visual transduction:
Fast: direct channel activation
Auditory
Auditory or Visual transduction:
No amplification of the transduction
Auditory
Photons: high energy but hard to catch (~100X106 photoreceptors)
Visual
Trillions of opsin molecules
Visual
Slow: G-protein cascade
Visual
Amplification: one photon closes many ion channels
Visual
