KIN 4571- Neuromotor Exam 1
sensory cranial nerves
1, 2, 8
(1a /11 afferent) are smaller in diameter
11 afferent
sensory endings that are only length sensitive (input from nuclear bag 2 and chains)
11 afferent axons - secondary afferent axons
(1a /11 afferent) have a faster action potential
1a
sensory ending that is velocity and length sensitive (input from bag 1 and 2 and chains)
1a afferent axon - primary sensory endings
motor cranial nerves
3, 4, 6, 11, 12
quadruped
4 legged animal
mixed cranial nerves
5, 7, 9, 10
Cranial Nerve 6
Abducens
an electrical impulse causing propagation of information
Action potential
midline
An imaginary line drawn down the center of the body, dividing it into right and left halves.
at which spinal nerve does it switch from coming out over the vertebrae to under the vertebrae
C8
muscle spindles project signals to (CNS/PNS)
CNS
motor neurons send info from _____ -> ______
CNS to PNS
interneurons send info from ____-> _____
CNS to other places in the CNS
respiration, mastication, locomotion, scratching are rhythmic activities that can be controlled by
Central Pattern generators
a slight depolarization of the postsynaptic cell, moving the membrane potential of that cell closer to threshold
EPSP - excitatory postsynaptic potential
cranial nerve 7
Facial
1b afferent is part of (muscle spindle/GTO)
GTO
in response to force/tension, the agonist muscle in inhibited and the antagonist muscle is excited
GTO - nonreciprocal (autogenic) inhibition
Cranial Nerve 9
Glossopharyngeal
Cranial nerve 12
Hypoglossal
a slight hyperpolarization of the postsynaptic cell, moving the membrane potential of that cell further from threshold
IPSP - inhibitory postsynaptic potential
increases the amplitude of EPSP above normal; allows you to stay in EPSP longer, giving you more time to reach an AP
Long term potentiation
______ detects muscle movement and stiffness
Muscle Spindles
a subset of neurotransmitters; chemicals released in the nervous system that influence the sensitivity of the receiving neuron to neurotransmitters
Neuromodulators
send signals to ONLY 1a afferent axons
Nuclear bag 1
Cranial Nerve 3
Oculomotor
Cranial Nerve 1
Olfactory
Cranial Nerve 2
Optic
the autonomic nervous system is part of the (CNS/PNS)
PNS
sensory neurons send info from the _____ -> _____
PNS to CNS
inhibitory intermotor neurons that effect alpha motor neurons and 1a inhibitory interneurons
Renshaw cells
proprioceptors
Sensory receptors, located in the muscles and joints, that provide information about body position and movement.
5 parts of the CNS
Spinal cord brainstem Diencephalon cerebellum cerebral hemispheres
Cranial nerve 5
Trigeminal
Cranial Nerve 4
Trochlear
T/F: one alpha motor neuron can innervate/control several muscle fibers
True
Cranial nerve 10
Vagus
cranial nerve 8
Vestibulocochlear
a chemical impulse causing the propagation of info
action potential
The lateral zone of the reticular formation is responsible for what type of impulses?
afferent sensory input
non reciprocal inhibition occur by inhibition: negative input to (agonist/antagonist) muscle
agonist
extrafusal muscle fibers are controlled by:
alpha motor neurons
non reciprocal inhibition occur by excitatory processes: positive input to (agonist/antagonist) muscle
antagonist
Rostral (biped-head)
anterior - towards the face
ventral (biped body)
anterior- front side/belly
axons running in rostral direction
ascending
golgi tendon organs are located _____
at muscle tendon junction
sensory endings (1a and 11 afferent) are located
at the center of a intrafusal muscle fiber
gamma motor axons are located:
at the end of an intrafusal muscle fiber
What does the brain stem control?
automatic behaviors muscle tone conscious behaviors and feelings
Inferior
away from the head, towards the bottom
lateral
away from the midline
distal
away from the trunk
axoaxonic synapse
axon to axon
axodendritic synapse
axon to dendrite
axosomatic synapse
axons to cell bodies
nuclear (bags/chains) have bulges
bags
a neuron with the cell body in the middle
bipolar
what is the function of peripheral nerves
carry sensory and motor info to and from the CNS - somatic and visceral components
cranial nuclei
cell bodies and dendrites in the brainstem
neural circuitry of rhythmic cycles such a breathing
central pattern generators
parts of the spinal cord
cervical enlargement, thoracic segment, lumbar enlargement
Nuclear bag 1 is sensitive to
changes in velocity
_____responds to influences to control CPGs
command neurons
heteronymous control
controlling muscles in movements that are not the agonist(primary mover) - involves disinhibition
several inputs from different locations projecting to 1 neuron or location
convergence
spinal cord nuclei
cranial nerve 11
medulla nuclei
cranial nerves 5, 7-12
pons nuclei
cranial nerves 5-9
midbrain nuclei
cranial nerves: 3, 4, 5
decussate
cross over midline
ipsilateral flexion/contralateral extension
crossed extension- ex, stepping on something sharp
axons running in a caudal direction
descending
reduces inhibition by inhibition; stopping something from stopping
disinhibition
what causes cocontraction
disinhibition
when an impulse is sent from the agonist muscle-> branches and then affects the antagonist muscle (2 synapses)
disynaptic (reciprocal) inhibition
one neuron affecting multiple targets/locations
divergence
sensory neurons are also called
dorsal root ganglion
gamma (static/dynamic) send stretch impulses to Nuclear bag 1 muscle fibers
dynamic
motor neurons send their signals to:
effector muscles OR muscle spindles
The medial zone of the reticular formation is responsible for?
efferent motor output
depolarization
excitatory (+)
cylindrical shaped muscle cells
extrafusal muscle fibers
Cranial Nerve 6: Abducens function? sensory/motor?
eye movement - 1 muscle motor
Cranial Nerve 3: Oculomotor function? sensory/motor?
eye movement; motor
Cranial Nerve 4: Trochlear function? sensory/motor?
eyemovemnet - 1 muscle motor
Cranial Nerve 7: Facial function? sensory/motor?
face movement; taste on the anterior 2/3 BOTH motor and sensory
sympathetic nervous system
fight or flight
rate modulation
firing rate, increasing/decreasing the number of action potentials
crossed extension is an example of what reflex
flexor reflex
List the cerebral lobes (hemispheres)
frontal. parietal, temporal, optical
vertical plane dividing the front and back
frontal/coronal
get rid of slack in the extrafusal/intrafusal muscle fibers by contracting at the same time, to prepare for readiness
gamma motor neurons
cell bodies in the PNS are called
ganglia
group of functionally related nerve cell bodies
ganglia
respond to force and tension
golgi tendon organs
nuclei and ganglia make up
gray matter
in the cerebral cortex ____ matter surrounds the _____ matter
grey; white
Cranial Nerve 11: Spinal Accessory function? sensory/motor?
head rotation and shoulder shrug Motor
Cranial Nerve 8: Vestibulocochlear function? sensory/motor?
hearing and balance sensory
CPGs are influanced by:
higher brain centers afferent feedback limb/body position
parasympathetic nervous system
homeostasis
a plane that is parallel to the ground; when the body is upright it divides it into top and bottom
horizontal plane
muscle spindles are located _______
in muscle fibers
rostral
in the direction of the face
caudal (biped-body)
inferior- towards the feet
ventral (biped -head)
inferior; towards the bottom of the face
Hyperpolarization
inhibitory (-)
Cranial Nerve 5: Trigeminal function? sensory/motor?
innervates muscles for mastication (tri- eat 3 meals a day); and sensory to face Both sensory and motor
afferent
input to the CNS
99.9% of all neurons are _____
interneurons
what neurons are located in the intermediate zone of gray matter
interneurons
for voluntary movements motor neurons receive info from:
interneurons / cerebral cortex
reticular formation is made up of
interneurons and nerve fibers (mostly cell bodies in the tegmentum)
what neurons are located in the dorsal horn of gray matter
interneurons and sensory neurons
main part of a muscle spindle
intrafusal muscle fibers
movement in response to afferent stimulus
involuntary movement
what happens when a renshaw cell is excited
it releases inhibitors
one neuron effects multiple targets differently; helps control the intensity of the impulse
lateral (surround) inhibition
reflexive adjustments made by sudden load disturbances this reflex can depend on the instructions ex. getting handed something very heavy
long loop transcortical responses
dendrites
mainly receive info
axons
mainly send info
GTO go with (many/singular) muscle fibers
many - global representation of the muscle
parts of the brainstem
midbrain, pons, medulla oblongata
The parts of the brainstem are
midbrain, pons, medulla oblongata tegmentum and basal portion
Interoceptors
monitor internal organ activity
Reflex pathway with only one synapse between the sensory and motor neurons (ex: knee-jerk).
monosynaptic reflex - stretch reflex
postural muscles have (more/less) GTO
more
white matter
mostly myelinated axons
what kind of receptors control muscle contractions
motor neurons
what neurons are located in the ventral horn of gray matter
motor neurons
alpha motor neuron + extrafusal muscle fibers
motor unit
Cranial Nerve 12: Hypoglossal function? sensory/motor?
movement of tongue motor
a neuron with the cell body on the end
multipolar
most abundant neuron in the CNS
multipolar neuron
1a/ 11 afferents are part of (muscle spindles/GTO)
muscle spindle
respond to stretch and lengthening
muscle spindles
Why is white matter white?
myelin sheaths which are white in color cover most axons
bundle of axons in the PNS
nerve
gray matter
nerve cell bodies and dendrites
can be releases with neurotransmitters
neuropeptides
Selective inhibition of agonist, synergists, and antagonist muscles. Coordinates actions of muscles during limb movement
nonreciprocal (autogenic) inhibition
send signals to BOTH 1a and 11 afferent axons
nuclear bag 2 and nuclear chains
what intrafusal muscle fibers are sensitive to changes in length
nuclear bag 2 and nuclear chains
Cell bodies in the CNS are called
nuclei
contralateral
on the opposite side of the body
ipsilateral
on the same side of the body
Cranial Nerve 10: Vagus function? sensory/motor?
organs of the neck, chest, gut, taste in the throat BOTH
efferent
output from the CNS- Exiting the CNS
nociceptors
pain receptors
similar information is transmitted through multiple sources (redundancy)
parallel processing
vertical plane passing through the body from front to back, dividing the body into UNEQUAL left and right sides
parasagittal plane
reticular activating system
part of the reticular formation that is responsible for wakefulness
nerves that are part of the PNS, they come out of the muscles to the spinal cord
peripheral nerves
all reflexes must have what 4 things?
peripheral receptors afferent nerves efferent nerves effectors
dorsal (biped body)
posterior - backside
occurs when the neurotransmitter binding to the postsynaptic neuron is effected; results in an IPSP
postsynaptic inhibition
increased amount of neurotransmitters released by the presynaptic terminal; results in an increased EPSP
presynaptic facilitation
a decrease in the amount of neurotransmitters released by the presynaptic terminal; results in a decreased effect on the postsynaptic neuron
presynaptic inhibition
muscle receptors influence _____
proprioception
a neuron with a cell body on the side
pseudounipolar
sensory neuron signal pathway
receptor organ -> afferent fibers-> spinal cord -> either motor neurons or higher brain centers
voltage change in the response to a stimuli
receptor potential
thermoreceptors
respond to changes in temperature
Photoreceptors
respond to light (rods and cones)
Mechanoreceptors
respond to touch, pressure, vibration, stretch, and itch
the voltage charge across a nerve cell membrane at rest
resting potential
important in regulating the sleep/wake cycle, arousal, alertness, and motor activity
reticular formation
when axons receive info it is called
retrograde
a vertical plane that divides the body into right and left parts, EQUALLY
sagittal plane
motor neurons receive signals from _____ neurons for reflex movements
sensory
Exterocepters
sensory information about the external environment hearing, sight, smell, taste, touch, temp, pain
receptors for vision, temp, smell, pressure, touch, pain, hearing, and movement changes
sensory neurons
Chemoreceptors
sensory neurons that respond to chemical stimuli
3 functions of the spinal cord
sensory processing motor output autonomic output
Cranial Nerve 1: Olfactory function? sensory/motor?
sensory, smell
effectors
skeletal muscles
when multiple AP occur at the same time
spatial summation
Cranial nerve 11
spinal accessory
Motor unit recruitment: size principle
starts with a small number of motor units and works up to larger numbers
gamma (static/dynamic) send stretch impulses to Nuclear bag 2/chain muscle fibers
static
Rostral (biped-body)
superior- towards the head
dorsal (biped-head)
superior; makes an arc from the top of the head to the back of the head
Cranial Nerve 9: Glossopharyngeal function? sensory/motor?
swallowing, taste on posterior 1/3 of the tongue BOTH
2 parts of the autonomic nervous system
sympathetic and parasympathetic
outside of the neuron and conveys messages
synapse
when the same action results from one impulse in 2 muscles
synergist muscle reflex
when one AP occurs right after the other
temporal summation
parts of diencephalon
thalmus and hypothalmus
Where do Renshaw cells receive input from?
the a.m.n it innervates descending tracts from higher brain centers different segments of the spinal cord
is the duration or amplitude of an action potential more important
the duration - you can change the duration but you can NOT change the magnitude
median
the middle
the number of alpha motor neurons per muscle fiber depends on _____
the need for fine motor control - more fine motor control = less on the same a m.n.
enteric nervous system
the nervous system of the smooth muscles in the digestive (GI) tract
what happens when a renshaw cell is inhibited
they do nothing
Superior
toward the head
caudal (quadruped)
toward the tail
dorsal (quadruped)
towards the back
posterior
towards the back
ventral (quadraped)
towards the belly
Anterior
towards the front
cranial
towards the head
rostral (quadruped)
towards the head
medial
towards the middle
proximal
towards the trunk
bundle of axons in the CNS
tract
a plane that is perpendicular to the long axis
transverse plane
T/F: non reciprocal inhibition can occur by both inhibitory and excitatory processes
true
T/F: synapses can be strengthened/weakened with increased/decreased use
true
slow twitch fibers - type 1 or 2? - function?
type 1; endurance
fast twitch fibers - type 1 or 2? - function?
type 2; power
Cranial Nerve 2: optic function? sensory/motor?
vision, sensory
choosing to move
voluntary movement
Cocontraction
when the antagonist contracts at the same time as the agonist
threshold
when this voltage is reached it results in an action potential
Tracts and Nerves make up
white matter
in the spinal cord _____ matter surrounds the _____ matter
white; grey
pain receptors excite the flexor muscle and inhibit the extensor muscle
withdrawal reflex (flexor reflex)
can reflexes be modified by other signals within the body?
yes
