Chapter3

Question 1

What directs the coordinated actions of muscles?

Answer 1

Central nervous system

Question 2

What are the two main components of the central nervous system?

Answer 2

Brain and spinal cord

Question 3

What do we adapt and improve through practice?

Answer 3

Motor skills

Question 4

What are skeletal muscles?

Answer 4

Muscles that attach to the skeleton

Question 5

What is the function of flexors?

Answer 5

Bend a joint

Question 6

What is the function of extensors?

Answer 6

Straighten a joint

Question 7

What is the role of flexors and extensors?

Answer 7

Work in opposition

Question 8

What muscle contracts to bend the elbow?

Answer 8

Biceps

Question 9

What muscle relaxes when bending the elbow?

Answer 9

Triceps

Question 10

What are muscles called that promote movement?

Answer 10

Agonists

Question 11

What are muscles called that oppose or inhibit movement?

Answer 11

Antagonists

Question 12

What allows rapid movements like throwing a dart?

Answer 12

Agonists and antagonists

Question 13

What is co-contraction?

Answer 13

Simultaneous contraction

Question 14

What does co-contraction stabilize?

Answer 14

Movement control

Question 15

Who controls skeletal muscle movement?

Answer 15

Central nervous system

Question 16

What is a skeletal muscle made up of?

Answer 16

Muscle fibers

Question 17

What controls each muscle fiber?

Answer 17

Alpha motor neuron

Question 18

Where do alpha motor neurons originate?

Answer 18

Spinal cord or brain

Question 19

What is the link between CNS and skeletal muscles?

Answer 19

Motor unit

Question 20

What is reciprocal inhibition?

Answer 20

Flexor relaxes, extensor activates

Question 21

Where do inhibitory interneurons operate?

Answer 21

Within the spinal cord

Question 22

What activates inhibitory interneurons?

Answer 22

Original sensory stimulus

Question 23

What does the simplest reflex involve?

Answer 23

Synchronous activation of motor neurons

Question 24

What is the function of many reflexes?

Answer 24

Protect from injury

Question 25

What happens during the 'knee jerk' reflex?

Answer 25

Lower leg swings forward

Question 26

How does the reflex help when jumping off a chair?

Answer 26

Promotes knee muscle contraction

Question 27

What triggers the flexion withdrawal reflex?

Answer 27

Sharp object

Question 28

What sends a message to the spinal cord in the flexion withdrawal reflex?

Answer 28

Pain receptors

Question 29

What happens to the leg when the flexion withdrawal reflex occurs?

Answer 29

Leg is lifted

Question 30

What must be activated in the opposite leg during the reflex?

Answer 30

Extensors

Question 31

What is the flexion crossed extension reflex?

Answer 31

Prevents falling over

Question 32

What do muscle spindles provide information about?

Answer 32

Muscle length changes

Question 33

What type of reflex is the 'knee jerk' response?

Answer 33

Stretch reflex

Question 34

Where are the circuits that control reflexes located?

Answer 34

Spinal cord

Question 35

What do muscle spindles sense?

Answer 35

Stretch extent and speed

Question 36

What activates the alpha motor neurons in the stretch reflex?

Answer 36

Signals

Question 37

What is tested when a doctor taps a muscle tendon?

Answer 37

Reflexes

Question 38

What do muscle spindle sensory fibers send to the spinal cord?

Answer 38

Impulses

Question 39

What is flexion withdrawal?

Answer 39

Leg lifted from sharp object

Question 40

What is the crossed extension reflex?

Answer 40

Opposite leg extends for balance

Question 41

What do motor neurons do?

Answer 41

Carry instructions from the brain

Question 42

How long can motor neurons be?

Answer 42

Stretch length of leg

Question 43

What do tendon feedback systems detect?

Answer 43

Force or tension

Question 44

What do feedback systems allow the brain to do?

Answer 44

Fine-tune muscle behavior

Question 45

Examples of tasks using feedback systems?

Answer 45

Sipping, throwing

Question 46

What do spinal circuits control?

Answer 46

Voluntary behaviors

Question 47

What generates rhythmic muscle activation for locomotion?

Answer 47

Neurons in spinal circuits

Question 48

What types of movements are central pattern generators responsible for?

Answer 48

Walking, flying, swimming, breathing

Question 49

What are central pattern generators?

Answer 49

Spinal circuitry for movement

Question 50

What is the purpose of studying central pattern generators?

Answer 50

Recover function after paralysis

Question 51

Where do the most complex movements originate?

Answer 51

Input from the brain

Question 52

What is the role of higher brain regions?

Answer 52

Initiate motion and coordinate movement

Question 53

What brain area is essential for voluntary movement?

Answer 53

Motor cortex

Question 54

What do neurons in the motor cortex control?

Answer 54

Activation of alpha motor neurons

Question 55

What is the role of neurons controlling functionally related muscles?

Answer 55

Finely tuned motor skills

Question 56

What can other motor cortex neurons direct?

Answer 56

Coordinated limb movement

Question 57

Which regions modulate voluntary movement?

Answer 57

Basal ganglia, thalamus, cerebellum

Question 58

What does the motor cortex work with?

Answer 58

Other brain regions

Question 59

What do these brain regions influence?

Answer 59

Motor neurons in spinal cord

Question 60

What is the role of the basal ganglia?

Answer 60

Monitor and adjust motor performance

Question 61

What disease is associated with degeneration of neurons in the substantia nigra?

Answer 61

Parkinson's disease

Question 62

What neurotransmitter is involved in motor control affected in Parkinson's?

Answer 62

Dopamine

Question 63

What are the hallmark symptoms of Parkinson's disease?

Answer 63

Tremor, rigidity, akinesia

Question 64

What symptoms do individuals with Huntington's disease display?

Answer 64

Uncontrolled jerking movements

Question 65

What causes symptoms in Huntington's disease?

Answer 65

Loss of inhibitory neurons

Question 66

Which brain region is crucial for coordinating movement?

Answer 66

Cerebellum

Question 67

What does the cerebellum receive input from?

Answer 67

Sensory receptors and cortex

Question 68

What role do neurons in the cerebellum play?

Answer 68

Integrate sensory information

Question 69

What does the cerebellum enable?

Answer 69

Fluid movements

Question 70

What happens with cerebellar dysfunction?

Answer 70

Poor coordination

Question 71

What is a common cause of acquired cerebellar degeneration?

Answer 71

Long-term alcohol abuse

Question 72

What are typical symptoms of acquired cerebellar degeneration?

Answer 72

Poor coordination, unsteady walk

Question 73

How does the cerebellum assist in physical tasks?

Answer 73

Adapts to the unexpected

Question 74

What role does the cerebellum play in motor learning?

Answer 74

Refines motor programs

Question 75

How does the cerebellum help with movement changes?

Answer 75

Recalibrates movements

Question 76

What tasks does the cerebellum assist with?

Answer 76

Walking, speaking, music