Chapter 15: Disorders of Motor Functions

Question 1

Extensors

Answer 1

muscles that increase the angle of a joint

Question 2

Flexors

Answer 2

muscles that decrease the angle of a joint

Question 3

Agonists Muscles

Answer 3

promote movement

Question 4

Antagonist Muscles

Answer 4

oppose movement

Question 5

Synergists Muscles

Answer 5

assist the agonist muscles by stabilizing a joint or contributing additional force to the movement

Question 6

Pyramidal Motor System

Answer 6

• originates in the motor cortex

- provides control of delicate muscle movement

Question 7

Extrapyramidal System

Answer 7

• originates in the basal ganglia

- provides background for the more crude, supportive movement patterns

Question 8

Upper Motoneuron Leisons

Answer 8

can involve the motor cortex, the internal capsule, or other brain structures through which the corticospinal or corticobulbar tracts descend, or the spinal cord

Question 9

Lower Motoneuron Lesions

Answer 9

disrupt communication between the muscle and all neural input from spinal cord reflexes, including the stretch reflex, which maintains muscle tone

Question 10

Myasthenia Gravis *****
Definition

Cause

Answer 10

• disorder of transmission at the neuromuscular junction that affects communication between the motoneuron and the innervated muscle cell
• autoimmune disease caused by antibody-mediated loss of acetylcholine receptors in the neuromuscular junction

Question 11

Peripheral Nerve Regeneration

Answer 11

• damage to a peripheral nerve axon: due to injury or neuropathy, results in degenerative changes, followed by breakdown of the myelin sheath and schwann cells
• regeneration factors: proximity to soma, crushing versus cutting

Question 12

Peripheral Nerve Regeneration

Answer 12

• damage to a peripheral nerve axon: due to injury or neuropathy, results in degenerative changes, followed by breakdown of the myelin sheath and schwann cells
• regeneration factors: proximity to soma, crushing versus cutting

Question 13

Peripheral Neuropathy
Definition
Results
Involvement

Answer 13

• definition: any primary disorder of the peripheral nerves
• results: muscle weakness, with or without atrophy and sensory changes
• involvement: can involve a single nerve (mononeuropathy) or multiple nerves (polyneuropathy)

Question 14

Mononeuropathis

Answer 14

cause by localized conditions such as trauma, compression or infections that affect a single spinal nerve, plexus, or pheripheral nerve trunk

Question 15

Polyneuropathy

Answer 15

involve demyelination or axonal degeneration of multiple peripheral nerves that lead to symmetric sensory, motor, or mixed sensorimotor deficits

Question 16

Lead Toxicity would result in what condition

Answer 16

Polyneuropathy

Question 17

Nerve Root Injuries

Answer 17

ruptured intervertebral disk

• sensory deficits
• motor weakness

Question 18

Cerebellum

Answer 18

• coordination of motor movement

Question 19

Basal Ganglia

Answer 19

• group of deep, interrelated subcortical nuclei that play an essential role in control of movement
• they receive indirect input from cerebellum and from all sensory systems, including vision, and direct input from motor cortex

made up of the: caudate nucleus, putamen, globus pallidus in the forebrain

Question 20

Parkinson Disease *****
Definition
Characteristics
Clinical Syndrome

Answer 20

• definition: a degenerative disorder of basal ganglia function that results in variable combinations of tremor, rigidity and bradykinesia
• characteristics: progressive destruction of the nigrostriatal pathway, with subsequent reduction in striatal concentrations of dopamine
• clinical syndrome: parkinsonism

Question 21

Amyotrophic Lateral Sclerosis (ALS)

Answer 21

• devastating neurologic disorder that selectively affects motor function
• disease typically follows a progressive course, with a mean survival period of 2-5 years from the onset of symptoms

Question 22

Multiple Sclerosis (MS)

Answer 22

demyelinating disease of the CNS

Question 23

Spinal Cord Injury *****

Answer 23

• damage to the neural elements of the spinal cord
• etiology: MVAs, falls, violence, sports
• damage to the vertebral column, supporting ligaments and spinal cord
• sensory and motor function