Which one of these is true about sensory information?
It is the process by which the brain makes interpretations about a stimulus.
It is a process that can be tested by using a nerve conduction study.
It is the process by which the stimulus is sent to the appropriate cortical region.
It is the process by which intensity of responsiveness to stimulus is regulated by the body.
Which of these is true about sensation?
Can be tested by a nerve conduction study.
It is the process by which stimulus gets sent to appropriate cortical region.
It is the process by which we make meaningful explanations about stimulus.
It is the ability to distinguish between different sensation modalities.
The ability to make meaningful interpretations about a variety of stimuli...
is performed by integration of association areas in the brain.
is a process very similar to sensory discrimination in occupational therapy.
all of these are true
none of these are true
Which of these is true about primary afferent axons?
A-alpha fibers transmit diffuse pain signals, like chronic pain.
A-beta fibers have the largest diameter and are the most myelinated, they carry mechanosensation.
A-delta fibers are less myelinated than a-beta and have a smaller diameter size, the carry acute pain information.
C-fibers carry proprioception information and are the smallest diameter and are not myelinated.
C-fiber and a-delta fibers both carry pain, temperature and itch sensation.
Merkel's disc...
are subcutaneous mechanoreceptors
send information via A-delta axons
are sensitive to deep touch
are sensitive to superficial pressure
are sensitive to stretch
are tonic receptors
Which of these is not a subcutaneous mechanoreceptor?
hair follicle receptor
pacinian corpuscle
ruffini endings
free nerve endings
Meissner's corpuscle...
send signals via a-beta axon and are sensitive to deep vibration
have the same adaptation rate as pacinian corpuscles
have large receptive fields
are sensitive to sustained touch
Pacinian corpuscles...
have the same adaptation rate as ruffini endings
are sensitive to light vibration
are superficial mechanoreceptors
respond to stretch in skin
Which of these is true about ruffini endings?
respond to stretch
subcutaneous receptors
have same adaptation rate as pacinian corpuscle.
these are all true.
respond to sustained touch and superficial pressure. respond to light touch and vibration. They are both mechanoreceptors.
Which of these is a factor that influences tactile discrimination?
areas with higher density of mechanoreceptors have greater tactile discrimination
body parts with small cortical representations have greater tactile discrimination
the receptive field size of pacinian corpsucles allow for greater tactile discrimination
the smaller the number of receptors in a given region the finer two-point discrimination you can make
Which of these is true about the adaptation rate of mechanoreceptors?
Receptors like pacinian corpuscle have a sustained response to a stimulus
merkel's disc and meissner's corpuscles generate a sustained response to stimulus
phasic receptors respond quickly but if the stimulus persists they habituate and stop firing
Which of these is not true about somatotopy?
The hands, face and mouth have a large somatotopic representation in the cortex.
The back and calves have a small somatotopic representation in the cortex.
Areas with high density of mechanoreceptors also have a bigger representation in sensory cortex.
People with phantom limb pain experience pain because they receptors for pain are still their but the sensory cortex for that limb is not.
Dermatomes...
are areas of the skin innervated by left and right dorsal roots and single spinal segment
information coming from the skin and entering at that particular level
are used to understand sensory deficits of a spinal cord injury
Which of these is true about neglect syndrome?
damage on right side of brain causes person to be unable to see objects in left visual field
damage on right side of brain causes person to be unaware of any type of stimulus on left side of body or visual field
damage on the right side of brain causes person to be unaware of any type of stimulus on left sid eof body or visual field, resolved by turning head to side
person is unable to identify object by touch
Stereognosis
is a process mediated by anterior parietal cortex
is the process of integrating all senses to identify object
is the process of identifying object by touch and no sight
problem with visual tracts and inability to see in left visual field
Which of these is true about dorsal column medial lemniscal and spinothalamic tract?
the DCML and ST carry A-beta axons
the point of decussation for the DCML is at the medulla, the point of decussation for ST is at the level where it enters
the DCML carries a-beta and a-delta fibers whereas the ST carries c fibers
the ST has a more detailed projection to thalamus and cortex than the DCML
the transmission of information is slower in the DCML than in the ST
is the negative feeling you experience. are free branching unmyelinated never endings. is the conduction of information along pain pathways.
Sensitivity to pain in tissue that have already been damaged is..
nocioception
hyperalgesia
primary hyperalgesia
secondary hyperalgesia
Which of these increases sensitivity to other stimuli in nociceptors after an injury?
prostagladins
bradykins
substance P
K+ ions
Bradykins...
directly depolarize nociceptors
cause vasodilation in the region
causes swelling in region
acts on mast cells
Substance P...
is a neurotransmitter
is released by nociceptors
acts on white blood cells - mast cells - to release histamine
causes redness and swelling in region
Substance P and histamine....
cause redness and swelling in region
are neurotransmitters
are released by mast cells
has impact on action potential
COX-1...
is a necessary enzyme for synthesizing bradykins
ensures natural mucus lining of stomach
can be inhibited to decrease sensitivity of primary hyperalgesia
when inhibited does not affect stomach lining
C fibers...
have an excitatory effect on gate interneurons, activitating gate and allowing transmission of pain information
have an inhibitory effect on gate interneuron, inactivating gate and allowing transmission of pain information
have an excitatory effect on gate interneuron, activating gate and stopping transmission of pain information
have an inhibitory effect on gate interneurons, inactivating gate and stopping transmission of pain information
Simultaneous firing of a-beta/a-alpha and c fiber axons at the gate interneuron could result in...
activation of gate interneuron and closing off of pain transmission
inactivation of gate interneuron and closing off of pain transmission
activation of gate interneuron and continued transmission pain information
inactivation of gate interneuron and continued transmission of pain information
Which of these is not true about PAG?
causes direct release of serotonin
receives information about emotional status from amydala and prefrontal cortex
sends projections to raphe nuclei to release serotonin
when directly stimulated there is a decrease in pain
Endorphins...
are released by raphe nuclei
are widely distributed in CNS but concentrated in DCML tract
increase release of glutamate
inhibit release of glutamate
Which one of these neurotransmitter is used by the spinothalamic tract to aid in transmission of pain?
serotonin
endorphins
ACTH
glutamate
Which of these is true about opioids?
endorphins are opioids
opioids bind tightly to glutamate receptors to inhibit transmission of pain
profound analgesic with few side effects
released during states of flow
Which of these is NOT true about acupuncture?
at the spinal level stimulates endorphin releasing cells to inhibit pain at that level
causes release of enkaphalin by PAG which in turn causes release of serotonin and norepinephrine
modulates effect of secondary hyperalgesia
modulates effect of primary hyperalgesia
Which of these is not proprioceptive information?
current position of joints
tension on tendons
deep vibration
high frequency vibration
kinesthesia
Which of these is not part or directly communicates with muscle spindles?
nuclear bag fibers
1a afferents
alpha motor efferent
gamma motor efferent
Quick stretch activates which structure:
muscle spindle
nuclear bag fiber in muscle spindle
muscle fiber
golgi tendon organ
Gamma motor neurons....
adjust sensitivity of muscle spindle to changes in muscle length
synapse with alpha motor neurons in anterior horn
are located in the dorsal horn of spinal cord
adjust sensitivity of muscle fibers to changes in muscle length
In the myotatic stretch reflex
stretched muscle spindles facilitate alpha motor neuron discharge
gamma motor neurons discharge in response to muscle stretch
II afferent synapses with alpha motor neurons
1a afferent axons travels from DRG to synapse with alpha motor neurons at dorsal horn
Which of these is true about Golgi tendon organs?
the GTO is located in the intrafusal fibers of the muscle
Its II afferent axons from GTO send signals to interneuron in dorsal horn where they synapse with alpha motor neurons
has the same effect on alpha motor neurons as the 1a afferent of nuclear bag fibers
is stimulated by muscle stretch
loss of GTO organs results in an inability to modulate muscle force
The lower motor neuron
refers to the communication between an alpha motor neuron to muscle fiber
refers to communication between a gamma motor neuron and muscle spindle
refers to communication between gammas motor neuron and muscle fiber
refers to communication between alpha motor neuron and muscle spindle
Which of these is true about different type of muscle fibers?
deep postural muscle are made up entirely of slow oxidative fibers
muscles that maintain stability and posture are made up of type 2 fibers
fast glycolitic muscles are recruited first for a given movement
after brain damage there is spasticity in muscles that are largely dominated by white muscle fibers
white fibers are slow to contract
Which of these is not true about alpha motor neurons?
each muscle fiber is innervated by a single alpha motor neuron
alpha motor neurons innervate several muscle fibers
the greater the number of alpha motor neurons firing the greater the number of muscle fibers recruited
a motor unit is the total number of alpha motor neurons that innervate a single muscle
The greater the innervation ratio of motor units, the more likely that muscle is responsible for precise movements.
Which of these is not true about motor units?
fast motor units are made largely of white muscle fibers
the axon's that innervate muscle fibers that are used for high endurance activities have a large diameter
the firing properties of neurons that innervate muscles for high endurance are low frequency and steady
muscles that rapidly fatigue are innervated by axons with high velocity conduction
The collection of alpha motor neurons that innervate a single muscle is...
a motor unit
a motor neuron pool
an interneuron pool
all of the above
The is the outer covering the muscle fiber. The is the outer covering of the that make up the muscle fiber. s make up of the myofibrils and contains two types of filaments made up of and .
The structures that allows communication between the sarcoplasmic reticulum and the sarcolemma are the
t-tubules
myofibril
actin
The z-line is the boundary between two adjacent...
sarcolemmas
sarcomeres
myofibrils
muscle fibers
Which of these is structures is store house for the Ca+2 ions responsible for mediating muscle contraction?
sarcolemma
sarcoplasmic reticulum
Which of these is true about troponin?
Blocks actin from binding onto site on myosin thick filament
Blocks myosin from binding onto site on actin thin filament
Presence facilitates binding of myosin and actin during contraction
Ca2+ binds unto myosin and exposes actin to binding with troponin
Which of these is true about ACh role during muscle contraction?
binds to nicotinic receptors on post synaptic neuron
is released by gamma motor neuron
binds to nicotinic receptor of sarcoplasmic reticiulum
binds to nicotinic receptors of sarcolemma
Which of these is true about action potential during muscle contraction?
with enough alpha motor neurons firing on muscle fiber an action potential will be generated
a single excitatory action potential in muscle fiber will generate an action potential
action potential sweeps between adjacent sarcomeres via t-tubules
Which of these is true about muscle contraction?
ACh binds to troponin so that myosin binding sites may be exposed to actin
calcium ions released from sarcolemma binds to troponin so that actin may bind to troponin
as long as ACh and ATP are available muscle contraction will continue
shortening of sarcomere via actin filaments coming closer together is muscle contraction
Reuptake of ACh in synaptic cleft causes muscle to stop contracting and relax.
Which substance stops release of ACh from alpha motor neurons?
calcium
botox
acupuncture
All muscles that are primarily made of red fibers are made up of small motor units.