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