Neuro Week 2

Front 1

Reflexes are _____ systems that require ______

Back 1

Feedback
sensory input

Front 2

Where is the GTO located?

Back 2

In the aponerroses of the tendon

Front 3

Where is the muscle spindle located?

Back 3

Within the muscle

Front 4

GTO's are arranged in ____ with ____ muscle fibers

Back 4

-Series
-Extrafusal

Front 5

THe two classes of GTO's?

Back 5

-High Threshold
-Low Threshold

Front 6

Purpose of GTO?

Back 6

-Regulate Tension among motor units
-Protect muscle from self destruction

Front 7

What is the afferent axon type for GTO?

Back 7

Ib

Front 8

The Ib afferent axon synapes with INTERNEURONS that inhibit what?

Back 8

The alpha motor neuron of the GTO muscle.

Front 9

Are Low Threshold GTO's stimulated more or less often than other GTO's?

Back 9

MORE OFTEN
Thus they provide the greatest inhibition on the motor neuron pool

Front 10

Where are low threshold GTO's located?

Back 10

Close to the dendrites

Front 11

Where are High Threshold GTO's Located?

Back 11

In TERMINAL TENDONS and closer to the Soma.

Front 12

What type of inhibition do High Threshold GTO's provide?

Back 12

Powerful! Immediate relaxation of entire muscle!

Front 13

What does the muscle spindle aparatus do?

Back 13

Measures the length of motor unit and velocity of change in length.

Front 14

What two components does the muscle spindle aparatus have?

Back 14

Sensory and motor component

Front 15

Components of the Sensory receptor?

Back 15

-Nuclear Bag Receptor (Ia)
-Nuclear Chain Receptor (II)
- Flower Spray

Front 16

Components of the Motor Component?

Back 16

-Intrafusal muscle fibers
-Gamma Motor neuron

Front 17

Muscle spindle sensory receptors are ______with extrafusal fibers.

Back 17

in parallel

Front 18

The receptor for the primary muscle spindle (nuclear bag) has what type of afferent axon?

Back 18

Ia (FAST)

Front 19

The receptor for the secondary muscle spindle (flower spray) has what type of afferent axon?

Back 19

II

Front 20

THe receptor for the gollgi tendon organ has what type of afferent axon?

Back 20

Ib

Front 21

What is the target of the alpha motor neuron?

Back 21

The extrafusal muscle

Front 22

What is the target of the gamma motor neuron?

Back 22

Intrafusal muscle

Front 23

Stretch of intrafusal muscle happens. What results (4)

Back 23

-Nuclear bag receptor stimulated
-Increase Ia activity
-Excites motor neuron
(alpha motor neuron!!!)
-Motor neuron excites
extrafusal muscle

Front 24

What are the two modes of muscle activation?

Back 24

-Direct
-Fast, crude, startle reflex
-Indirect (gamma root system)
-Slow, precise voluntary activation

Front 25

Direct Method

Back 25

Alpha motor neuron stimulation unloads receptor

Front 26

_____ of alpha and gamma motor neurons eliminates the unloading of the nuclear bag receptor.

Back 26

Co-activation (there is no longer a large gap during the activation)

Front 27

Flexion Reflex Afferents

Back 27

-Activation by cutaneous afferents
-Cutaneous group II axons
-Provide withdrawal protection reflex

Front 28

What happens with activation of FRA's?

Back 28

-Activation by cutaneous group II axons
-Act. of ipsilateral flex musc.
-Inh. of ipsilateral exten musc
Crossed extension reflex by FRA's
-Facilitation of contralateral extensor muscles
-Inh of contralateral flexor musc

Front 29

Of the six descending motor tracts, which three mostly facilitate the flexor muscle groups?

Back 29

-Corticobulbospinal tract (CBST)
-Rubrospinal tract
-Medullary reticulospinal tract

Front 30

Of the six descending motor tracts, which three mostly facilitate the extensor muscle groups?

Back 30

-Lateral Vestibulospinal tract
-Pontine reticulospinal tract
-Medial vestibulospinal tract
-Cervical cord only!! Stabilizes head

Front 31

Innervations of the CBST? (4)

Back 31

-The red nucleus
-The motor parts of the reticular formation
-The motor nuclei of cranial nerves (except oculomotion)
-FLexors of the spinal cord
-10% go to extensors

Front 32

For the CBST, what type are the majority of connections in the brainstem?

Back 32

Bilateral

Front 33

For the CBST, what type of connections are the majority of connections in the spinal cord?

Back 33

Contralateral

Front 34

Where does the Rubrospinal tract originate?

Back 34

-In the red nucleus (in the mesencephalon)
-It crosses midline immediately!

Front 35

What does the Rubrospinal tract innervate contralaterally?

Back 35

-Motor nuclei of cranial nerves (except occulomotion)
-Flexors in spinal cord

Front 36

What does the Rubrospinal tract recieve its imput from?

Back 36

The CBST

Front 37

What are the two principle tracts of the reticulospinal tracts?

Back 37

-The pontine reticulospinal tract
-THe Medullary reticulospinal tract

Front 38

The pontine reticulospinal tract

Back 38

-Ipsilateral to pontine nuclei
-innervates EXTENSORS in the spinal cord

Front 39

THe medullary reticulospinal tract

Back 39

-Bilateral distribution
-innervates FLEXORS in the spinal

Front 40

Both reticulospinal spinal tracts recieve their input from....?

Back 40

The CBST

Front 41

Two tracts of the vestibulospinal tract?

Back 41

Lateral and Medial VST

Front 42

Connections of the Lateral VST?

Back 42

-Originates in lateral vestibular nucleusof medulla
-Descends ipsilateral
-Inervates EXTENSORS
-ANTI GRAVITY SYSTEM

Front 43

Connections of the Medial VST?

Back 43

-Originates in medial vestibular nucleus
-Descends ipsilateral to cervical levels only
-Powerful for head stability

Front 44

Do either of the VST recieve stimulation from the CBST?

Back 44

NO!!!

Front 45

Do leasions to M-I induce total paralysis?

Back 45

No, only paresis (no good muscle movement). THere are too many other factors involved.

Front 46

What do most M-I neurons code for?

Back 46

-Direction (which neurons are firing) i.e. left, right, up, down
-Force (Rate of firing)

Front 47

Red nucleus neurons code for what?

Back 47

Velocity of movement

Front 48

PMA (Pre-Motor area) neurons do what?

Back 48

-PRepare M-I for action!
-THey integrate multiple inputs to anticipate which M-I motor neurons to facilitate

Front 49

What do SMA (supplemental motor area) neurons do?

Back 49

-THey bring together multiple muscle groups to perform complex bilateral tasks

Front 50

PMS/SMA lesions produce what?

Back 50

Apraxia

Front 51

During a MSR test, a diminished or absent tendon reflex can mean afflicted what?

Back 51

-ALpha motor neuron
-ventral root
-spinal nerve
-peripheral nerve

Front 52

During a MSR test, an enhanced or spastic tendon reflex can mean afflicted what?

Back 52

-Motor Cortex
-Descending Motor Tracts

Front 53

ANything that is causing a decrease in the MSR is affecting what?

Back 53

The lower motor neuron!!

Front 54

Signs of LMN affliction?

Back 54

-Decrease MSR
-Weakness (NOT spastic)
-Muscle Denervation

Front 55

Signs of muscle dernervation?

Back 55

-Fasciculation (quivering of musc)
-Early phase
-Fibrillations (middle phase)
-Atrophy (late phase)

Front 56

Damage to the upper motor neurons will cause?

Back 56

An increase in the MSR
-Lesions involving M-I
-Lesions involving and part of CBST pathways
THIS IS BECAUSE IT INCREASES THE GAINS OF THE GAMMA LOOP

Front 57

-Biceps
-Triceps
-Brachioradialis
-Quadriceps
-Gastrocnemius

Back 57

-Musculocutaneous
-Radial
-Radial
-Femoral
-Sciatic

Front 58

-Biceps CordS
-Triceps
-Brachioradialis
-Quadriceps
-Gastrocnemius

Back 58

-Lateral
-Posterior
-Posterior

Front 59

-Biceps Root BOLD
-Triceps
-Brachioradialis
-Quadriceps
-Gastrocnemius

Back 59

-C6
-C7
-C5,6
-L4
S1,2

Front 60

What special fact is present in UMN affliction?

Back 60

NO signs of denervation!!!

Front 61

Signs of UMN affliction

Back 61

Flexion reflex absence
-Babinski, Bing
Muscle Weakness (spastic)

Front 62

Babinski test

Back 62

-Good (curl toes)
-Bad (moves/jerks foot up)
but not like being tickled

Front 63

Amputation without anastomosis can lead to?

Back 63

Phantom limb and the formation of plexiform neuroma

Front 64

Speed of nerve regeneration?

Back 64

1mm per day

Front 65

Symptoms of Spinal disc Syndrome?

Back 65

-UNILATERAL weakness
-Decreased MSR
-Pain with FOCUSED distribution

Front 66

What is the big danger with cervical disc herniations?

Back 66

Cord compression can lead to UMN signs in the lower extremeties if the motor tracts are affected.

Front 67

If there is general cirrcularish compression of the cervical spinal cord, what signs do you look for?

Back 67

Look for loss of nervous changes in the Lumbar region first, then thoracic, and then cervical. Lumbar on the outside of cord, and cervical is innermost!!!!!!