Motor I, II, and III Flashcards Preview

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Flashcards in Motor I, II, and III Deck (64):
1

Motoneurons innervating axial and proximal muscles are located (laterally/medially) in the ventral horn of the spinal cord.

Medially

2

Motoneurons innervating distal muscles are located (laterally/medially) in the ventral horn of the spinal cord.

Laterally

3

Motoneurons innervating extensor muscles are located (ventral/dorsal) to those innervating flexor muscles.

Ventral

4

(T/F) Interneuron pools in the intermediate gray that innervate motoneurons are segregated in the same way as motoneurons in the ventral horn.

True.

5

(T/F) Descending tracts are located in the white matter adjacent to the relevant motoneuron pools they control.

True.

6

Proprioceptive input to a cortical column arises in the joint (proximal/distal) to the muscle that the column controls.

Distal

7

Cutaneous input to a cortical column arises where?

From a skin region in the path of limb movement that the column controls.

8

Inputs to the cortical columns travel through the ______________ and _____________ thalamic nuclei.

Ventroanterior and ventrolateral thalamic nuclei

9

The standard visuo-motor reflex takes about ___ms.

240ms

10

The standard cortical reflex takes about ___ms.

120ms

11

90% of the corticospinal tract arises in the ____________ and ___________ cortices.

Precentral and postcentral

12

Pathways controlling axial and proximal muscles for use in posture typically undergo (phasic/tonic) innervation.

Tonic

(TPP) = Tonic, Proximal, Posture

13

Pathways controlling distal muscles for use in discrete movements typically undergo (phasic/tonic) innervation.

Phasic

(PDD) = Phasic, Distal, Discrete

14

Muscle tracts that make use of tonic innervation include:

  • Pontine reticulospinal
  • Vestibulospinal
  • Tectospinal

Tonic = Control Postuer (Axial and proximal muscle groups)

15

Muscle tracts that makes use of phasic innervation include:

  • Corticospinal
  • Rubrospinal
  • Medullary reticulospinal

Phasic = Control Discrete Muscle Movement (Distal muscle groups)

16

The lateral corticospinal tract primarily terminates upon (flexor/extensor) interneurons.

Flexor interneurons

17

The rubrospinal tract usually (activates/inhibits) flexors and (activates/inhibits) extensors of the upper body.

  • Activates flexors
  • Inhibits extensors

Massive effect on force (flexor part of emergency control; i.e. grabbing onto tree when you fall)

Acts on alpha motor neurons

18

The medullary reticulospinal tract usually (activates/inhibits) flexors and extensors.

Inhibits flexors
Inhibits extensors

19

(T/F) Upon entering sleep, the medullary reticulospinal tract hyperpolarizes the body's flexor and extensor interneurons. This is a defense mechanism to cause paralysis during sleep and prevent movement during vivid or imaginative dreams.

True.

20

The vestibulospinal tract primarily activates (flexor/extensor) alpha motor neurons and interneurons. It is important in maintaining balance and prevention of injury while falling.

Extensors

21

The pontine reticulospinal tract typically (activates/inhibits) extensor interneurons.

Activates extensors

Helps you stand up

22

The tectospinal tract activates (extensor/flexor) interneurons of the upper cervical areas to track objects on the edges of the field of vision by moving the neck.

Extensor

23

What path do fibers in the corticospinal tract travel after leaving the motor cortices?

  1. Corona radiata
  2. Internal capsule (posterior limb)
  3. Cerebral peduncle (middle third)
  4. Pons
  5. Pyramids
  6. Decussation into lateral and anterior corticospinal tracts

24

Glutamate is (excitatory/inhibitory).

Excitatory

25

Inputs to the striatum (caudate nucleus and putamen) from the cerebral cortices use the neurotransmitter _____________.

Glutamate

26

Inputs to the striatum (caudate nucleus and putamen) from the thalamus use the neurotransmitter ______________.

Glutamate

27

Inputs to the striatum (caudate nucleus and putamen) from the substantia nigra use the neurotransmitter ______________.

Dopamine

28

Inputs to the striatum (caudate nucleus and putamen) from the raphe nucleus use the neurotransmitter _______________.

Serotonin

29

Outputs from the striatum travel to the _________ and _________.

Globus pallidus and substantia nigra

30

The ___________ and __________ function to regulate output from the striatum.

Subthalamic nucleus and external pallidum (of globus pallidus)

31

Outputs travel from the striatum to the globus pallidus and substantia nigra. Outputs leaving the internal pallidum and substantia nigra then ascend to the ______________ and descend to the ____________ simultaneously.

Ascend to the thalamus (VA & VL)
Descend to the midbrain (Subthalamic Nuclei)

32

What are the key functions of the basal ganglia?

  • Preparation and planning of movement
  • Organization of sequence of movements
  • Learning of hierarchically organized movements
  • Sensory and motor modulation

33

What are the key functions of the cerebellum?

  • Unconscious control of movement
  • Regulation of rapid (preprogrammed) movements
  • Posture, muscle tone, and equilibrium

34

The archicerebellum (flocculonodular) lobe of the cerebellum is primarily involved in (distance judgments/vestibular balance and eye movements/muscle tone control).

Vestibular balance and eye movements

35

The paleocerebellum (anterior) lobe of the cerebellum is primarily involved in (distance judgments/vestibular balance/muscle tone control).

Muscle tone control

36

The neocerebellum (posterior) lobe of the cerebellum is primarily involved in (distance judgments/vestibular balance/muscle tone control).

Distance judgments

37

The cerebellar cortex has a _____________ outer layer, _____________ intermediate layer, and ____________ inner layer.

  • Outer molecular layer
  • Intermediate Purkinje layer
  • Inner granular layer

38

Mossy fibers terminate on glomeruli containing _____________ dendrites and _____________ axons.

  • Granule cell dendrites
  • Golgi cell axons

39

After receiving excitatory inputs from mossy fibers, granule cells climb to the molecular layer and bifurcate, forming ______________ that run perpendicular to the dendrites of Purkinje cells.

Parallel fibers

40

Parallel fibers provide excitatory input to ______________, which then travel through the cerebellar white matter and form inhibitory synapses on the cerebellar deep nuclei.

Purkinje cells

41

Parallel fibers provide excitatory input to what other two types of cells besides Purkinje cells?

  • Golgi cells (inhibitory output to mossy fibers cells)
  • Basket cells (inhibitory output to Purkinje cell one row on either side of the row that was activated by parallel fibers)

42

(Basket/Stellate) cells provide inhibition by terminating on Purkinje cell dendrites in the molecular layer.

Stellate

43

(Basket/Stellate) cells provide inhibition by surrounding the Purkinje cell body.

Basket cells

44

_____________ fibers provide excitatory input to Purkinje cells by wrapping around its cell body and proximal dendrites.

Climbing fibers

  • From inferior olive

45

An easy way to remember excitatory and inhibitory inputs is that excitatory inputs travel (up/down) and inhibitory inputs travel (up/down).

  • Excitatory travels up (Mossy fibers, granule cells that become parallel fibers, climbing fibers)
  • Inhibitory travels down (Stellate cells, basket cells, golgi cells, Purkinje cells)

46

___________ cells provide inhibition by terminating on granule cell dendrites within the glomerulus.

Golgi cells

47

(T/F) Climbing fibers originate in the superior olivary nucleus.

False. Climbing fibers arise exclusively from neurons in the contralateral INFERIOR olivary nucleus.

48

Afferent information about limb movements is conveyed to the cerebellum by the dorsal spinocerebellar tract for the (upper/lower) extremities.

Lower

49

Afferent information about limb movements is conveyed to the cerebellum by the cuneocerebellar tract for the (upper/lower) extremities.

Upper

50

Information about activity of spinal cord interneurons and intended pattern generator outputs is conveyed to the cerebellum by the ventral spinocerebellar tract for the (upper/lower) extremity interneurons.

Lower

51

Information about activity of spinal cord interneurons and intended pattern generator outputs is conveyed to the cerebellum by the rostral spinocerebellar tract for the (upper/lower) extremity interneurons.

Upper

52

Mossy fibers traveling through the dorsal spinocerebellar and cuneocerebellar tract enter the (ipsilateral/contralateral) cerebellum through the (inferior/middle/superior) cerebellar peduncle.

  • Ipsilateral cerebellum
  • Inferior cerebellar peduncle

53

(T/F) Olivocerebellar fibers decussate before entering the cerebellum as climbing fibers.

True.

54

Fibers from the most lateral portion of the cerebellum enter the ______________ deep cerebellar nucleus.

Dentate

55

Fibers from the intermediate portion of the cerebellum enter the ____________ and ____________ deep cerebellar nuclei.

Emboliform and globose

56

Fibers from the flocculonodular lobe and vermis, the most medial portions of the cerebellum, enter the ______________ deep cerebellar nucleus.

Fastigial

57

Most outputs of the cerebellum travel through the (superior/middle/inferior) cerebellar peduncle.

Superior

58

What cerebellar inputs travel through the middle cerebellar peduncle?

  • Pontocerebellar

59

What cerebellar inputs travel through the inferior cerebellar peduncle?

  • Dorsal (posterior) spinocerebellar
  • Cuneocerebellar
  • Olivocerebellar
  • Vestibulocerebellar
  • Reticulocerebellar

60

What cerebellar inputs travel through the superior cerebellar peduncle?

  • Ventral (anterior) spinocerebellar

61

What is the mnemonic to remember the deep cerebellar nuclei in order from most lateral to most medial?

Don't (Dentate) - Most lateral
Eat (Emboliform)
Greasy (Globose)
Food (Fastigial) - Most medial

62

All movements of the body have an underlying rhythm of __Hz.

10Hz

63

(T/F) A long latency reflex that stabilizes the body's posture will become weaker when elicited repetitively.

False. A long latency reflex that stabilizes the body's posture will become STRONGER when elicited repetitively.

64

What lesion will cause an intention tremor?

Lateral hemisphere of cerebellum

  • Dentate nucleus is located here
  • Dysmetria