Motor Systems ll Flashcards Preview

CMSD5290 Intro to Neuroscience > Motor Systems ll > Flashcards

Flashcards in Motor Systems ll Deck (19)
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1
Q

Corticospinal and corticobulbar axons
descend from cortex as the: (4)

A
  • Corona radiata (axons streaming from
    cortex)
  • Internal capsule (at level of basal
    ganglia)
  • Cerebral peduncles (at level of
    midbrain)
  • Pyramidal tract (at level of medulla)
2
Q

What consists the indirect (extrapyramidal) pathway?

A

Consists of cortical and brainstem
projections that have many synaptic
connections before reaching spinal cord
motor neurons.

3
Q

What is the indirect (extrapyramidal) pathway controlled by? (2)

A

-Basal Ganglia (i.e., caudate, putamen,
globus pallidus)
–Cerebellum

4
Q

What makes the basal ganglia a complex circuitry? (5)

A
  • Reciprocal connections to cortex
  • Reciprocal connections to substantia
    nigra
  • Projections to thalamus
  • Output to brainstem & spinal cord
  • Modulates activity in direct pathway
5
Q

The basal ganglia has ______________ and __________________ pathways.

A

Excitatory and inhibitory pathways

6
Q

What are the functions of the basial ganglia? (2)

A

Functions in controlling & coordinating
movement patterns for large groups of
muscles

7
Q

Damage to the basal ganglia can result in? (2)

A

–hypokinetic symptoms (e.g.,
Parkinson’s disease)
–hyperkinetic symptoms (e.g.,
Huntington’s disease)

8
Q

What is the role of the cerebellum?

A

Involved in movement coordination (i.e.,
timing, accuracy), motor learning, balance

9
Q

Where does the cerebellum receives sensory input from? (3)

A

spinal cord
(spinocerebellar pathways), brain stem &
cortex

10
Q

The cerebellum provides output (indirectly) to ____________________

A

spinal motor neurons

11
Q

What in the cerebellum allows it to adjust movements to match intentions?

A
  • Feedback circuit
12
Q

Organization of the cerebellum: Contains about ______ of all the neurons in he entire central nervous system

A

half

13
Q

Organization of the cerebellum: Divided into ___________________ with multiple __________

A

Two hemispheres
Lobes

14
Q

Organization of the cerebellum: __________ projects from the _______________ (eye movements, balance)

A

Flocculus
Ventral Surface

15
Q

Organization of the cerebellum:___________ protrudes along dorsal midline (termination site of spinocerebellar pathways)

A

Vermis

16
Q

Damage to the cerebellum results in:

A

Ataxia

17
Q

What is Ataxia?

A

problems with movement coordination & balance

18
Q

Characteristics of Lower motor neurons (LMN) (4)

A
  • PNS
  • Originate in brainstem as cranial nerves
  • Originate in spinal cord as spinal nerves
  • Terminate at muscles
19
Q

Characteristics of Upper motor neurons (UMN) (4)

A
  • CNS
  • Originate in cortex and terminate in brain stem
    (corticobulbar tract) or spinal cord (corticospinal tract)
  • Pyramidal system (CB & CS tracts) directly controls
    LMN’s
  • Extrapyramidal system influences pyramidal system &
    therefore indirectly controls LMN’s