Kin 372 exam 2
1. Know these terms and be able to use them (put them together!): axon, dendrite, resting potential,
cell body, collaterals, myelin sheath, nodes of Ranvier, action potential, graded potential, threshold,
pre- and post-synaptic membrane, depolarization, hyperpolarization, synaptic transmission, IPSP's;
EPSP's, saltatory conduction, nodes of Ranvier, temporal summation, spatial summation, integration
of signals, neurotransmitter, recruitment, motor neu- ron pool, myelin, sensory neurons, motor
neurons, interneurons, dorsal root ganglia, ventral horn, and neuromuscular junction.: Axon: signal
is conducted down
dendrite: where signal input comes from
resting potential: the difference in charges between membranes the inside of a cell is negative
collaterals: branches of an axon
myelin: insulates and speeds transduction nodes: speed
transduction
action potential: once a neuron reaches threshold and an all or none event occurs (select cells)
does not dissipate the same every time, cell becomes more positive because of influx of sodium
graded potential: hyper or depolarization that dissipates
threshold: depolarization high enough for an AP to occur -55 and higher
pre synaptic sends the signal post synpatic recieves and is where the integration occurs (axon
hillock)
depolarization: more positive
hyperpolarization: more negative IPSPS:
inhibitory
EPSP: excitatory
saltatory: jumping due to nodes
temporal: many in a row from same neuron spatial:
many different neurons
sensory neuron: dorsal root ganglion (cell bodies), unipolar, afferent
motor neurons: ventral horn, alpha motor neurons straight to muscle, efferent, multipolar
motor neuron pools: ventral horn cell bodies and EPSPs and IPSPs for functional groups
repolarization: opening of K channels
2. Be able to discuss how EPSPs and IPSPs influence the electrical potential of the motor neuron
pool and to determine whether an action takes place or not on a given motor unit. Where do the
EPSPS and IPSP's come from that influence the motor neuron pools?: EPSPS and IPSPS come to
motor neuron
, Kin 372 exam 2
pool which is a functional group not a single muscle and decide motor recruitment. There are
multiple inputs from motor tracts, sensory neurons and interneurons, this is the beginning of the
Final Common Pathway.
Epsps and ipsps are summated at the axon hillock of interneurons traveling from the brain to the
ventral horn of the spinal cord where they synapse with motor neurons. if threshold is reached
an action potential will be transmitted down the axon of the interneuron and excite the motor
neuron. Each motor neuron synapses with muscle fibers that make up a motor unit. All muscle
fibers in that unit will contract if an action potential excites that motor neuron. IPSps inhibit
motor
3. Why are interneurons in the spinal cord important?: Facilitate connections between the brain
and motor neurons and sensory and motor neurons?
some reflexes
Polysynaptic use interneurons, monosynaptic just sensory and motor
interneurons make up the corticospinal tract
4. What are some examples of spinal level reflexes? How do we know that they are spinal level and
not brainstem or cerebellar level? (M1, M2, M3 loops) Can spinal level reflexes be inhibited? Why?
Why not? What mechanisms are involved? (Use terms from terms listed above.) (This answer from
early in this section and later in the section.): Spinal level reflexs
Stretch reflex
Flexion reflex
Grasping reflex
Crossed extensor
Extensor thrust
Plantar
They take shorter amount of time so we know it inly goes to the spinal cord and not further up
M1 spinal 30-50
M2 cerebella's 50-80
M3 cortex 120-200
Triggered response: 80-120
, Kin 372 exam 2
Yes spinal level reflex can be inhibited with conscious effort. Relax quads instead contract
5. What are CPG's? What is the animal evidence for CPG's? Is the evidence that they exist in
humans? If so, describe.: CPGS: group of interneurons that produce motor response (motor
neurons) without the brain, controlled by the spinal cord,
NOT A GROUP OF MOTOR NEURONS
-rhythmic and sustained movement, involuntary
6. What is a motor unit (small vs. large)? How is force increased gradually? What determines
recruitment and the size principle? How is control of a fine motor skill, like surgery, accomplished
and how does that differ from hammering a nail? Or throwing a shot put?: Small: low threshold,
low level of fibers innervated, fine movements low force
Low force, no fatigue
Large: high threshold, many muscle fibers, huge force, high fatigue
Forced increased gradually as more motor units recruited as more Epsps sent to motor neuron
pool and integrated
Surgery: small
Hammering: larger force/ medium still accuracy Shot
out: large
7. 8. What is kinesthesis? How does it differ from proprioception? What are some ways
proprioception contributes to motor control? Which propriocep- tors are more important for
kinesthesis?: Kinesthesis is the perception of where you are in space it used proprioception
which is the actually sensory information feedback. Proprioception tells the brain where the
body is posititioned so you can move your body without having to see it
muscle spindles: stretch in muscle
joint receptors: movement angular in joint capsul GTOs:
contraction effort in tendon
cutaneous: pressure
vestibular apparatus: inner ear, accleration
8. 9. Trace the path from the sensory receptor (such as GTO or muscle spindle) to the cerebral cortex.:
9. 10. Know what these terms refer to: adequate stimulation, intensity coding, and sensory
adaptation. How do they contribute to utilizing sensory informa-
1. Know these terms and be able to use them (put them together!): axon, dendrite, resting potential,
cell body, collaterals, myelin sheath, nodes of Ranvier, action potential, graded potential, threshold,
pre- and post-synaptic membrane, depolarization, hyperpolarization, synaptic transmission, IPSP's;
EPSP's, saltatory conduction, nodes of Ranvier, temporal summation, spatial summation, integration
of signals, neurotransmitter, recruitment, motor neu- ron pool, myelin, sensory neurons, motor
neurons, interneurons, dorsal root ganglia, ventral horn, and neuromuscular junction.: Axon: signal
is conducted down
dendrite: where signal input comes from
resting potential: the difference in charges between membranes the inside of a cell is negative
collaterals: branches of an axon
myelin: insulates and speeds transduction nodes: speed
transduction
action potential: once a neuron reaches threshold and an all or none event occurs (select cells)
does not dissipate the same every time, cell becomes more positive because of influx of sodium
graded potential: hyper or depolarization that dissipates
threshold: depolarization high enough for an AP to occur -55 and higher
pre synaptic sends the signal post synpatic recieves and is where the integration occurs (axon
hillock)
depolarization: more positive
hyperpolarization: more negative IPSPS:
inhibitory
EPSP: excitatory
saltatory: jumping due to nodes
temporal: many in a row from same neuron spatial:
many different neurons
sensory neuron: dorsal root ganglion (cell bodies), unipolar, afferent
motor neurons: ventral horn, alpha motor neurons straight to muscle, efferent, multipolar
motor neuron pools: ventral horn cell bodies and EPSPs and IPSPs for functional groups
repolarization: opening of K channels
2. Be able to discuss how EPSPs and IPSPs influence the electrical potential of the motor neuron
pool and to determine whether an action takes place or not on a given motor unit. Where do the
EPSPS and IPSP's come from that influence the motor neuron pools?: EPSPS and IPSPS come to
motor neuron
, Kin 372 exam 2
pool which is a functional group not a single muscle and decide motor recruitment. There are
multiple inputs from motor tracts, sensory neurons and interneurons, this is the beginning of the
Final Common Pathway.
Epsps and ipsps are summated at the axon hillock of interneurons traveling from the brain to the
ventral horn of the spinal cord where they synapse with motor neurons. if threshold is reached
an action potential will be transmitted down the axon of the interneuron and excite the motor
neuron. Each motor neuron synapses with muscle fibers that make up a motor unit. All muscle
fibers in that unit will contract if an action potential excites that motor neuron. IPSps inhibit
motor
3. Why are interneurons in the spinal cord important?: Facilitate connections between the brain
and motor neurons and sensory and motor neurons?
some reflexes
Polysynaptic use interneurons, monosynaptic just sensory and motor
interneurons make up the corticospinal tract
4. What are some examples of spinal level reflexes? How do we know that they are spinal level and
not brainstem or cerebellar level? (M1, M2, M3 loops) Can spinal level reflexes be inhibited? Why?
Why not? What mechanisms are involved? (Use terms from terms listed above.) (This answer from
early in this section and later in the section.): Spinal level reflexs
Stretch reflex
Flexion reflex
Grasping reflex
Crossed extensor
Extensor thrust
Plantar
They take shorter amount of time so we know it inly goes to the spinal cord and not further up
M1 spinal 30-50
M2 cerebella's 50-80
M3 cortex 120-200
Triggered response: 80-120
, Kin 372 exam 2
Yes spinal level reflex can be inhibited with conscious effort. Relax quads instead contract
5. What are CPG's? What is the animal evidence for CPG's? Is the evidence that they exist in
humans? If so, describe.: CPGS: group of interneurons that produce motor response (motor
neurons) without the brain, controlled by the spinal cord,
NOT A GROUP OF MOTOR NEURONS
-rhythmic and sustained movement, involuntary
6. What is a motor unit (small vs. large)? How is force increased gradually? What determines
recruitment and the size principle? How is control of a fine motor skill, like surgery, accomplished
and how does that differ from hammering a nail? Or throwing a shot put?: Small: low threshold,
low level of fibers innervated, fine movements low force
Low force, no fatigue
Large: high threshold, many muscle fibers, huge force, high fatigue
Forced increased gradually as more motor units recruited as more Epsps sent to motor neuron
pool and integrated
Surgery: small
Hammering: larger force/ medium still accuracy Shot
out: large
7. 8. What is kinesthesis? How does it differ from proprioception? What are some ways
proprioception contributes to motor control? Which propriocep- tors are more important for
kinesthesis?: Kinesthesis is the perception of where you are in space it used proprioception
which is the actually sensory information feedback. Proprioception tells the brain where the
body is posititioned so you can move your body without having to see it
muscle spindles: stretch in muscle
joint receptors: movement angular in joint capsul GTOs:
contraction effort in tendon
cutaneous: pressure
vestibular apparatus: inner ear, accleration
8. 9. Trace the path from the sensory receptor (such as GTO or muscle spindle) to the cerebral cortex.:
9. 10. Know what these terms refer to: adequate stimulation, intensity coding, and sensory
adaptation. How do they contribute to utilizing sensory informa-
