Motor Control I

Question 1

Synergists

Answer 1

Multiple muscles working together to either flex or extend

Question 2

Order of muscle composition largest to smallest

Answer 2

Muscle -> Fascicle -> Single Muscle Fiber (cell) -> Myofibril

Question 3

Lower Motor Neurons (Alpha Motor Neurons)

Answer 3

Triggers the contractions of muscles

Question 4

Motor Unit

Answer 4

One alpha motor neuron and all the muscle fibers it innervates

Question 5

Motor Pool

Answer 5

All the alpha motor neurons that innervate a muscle

Question 6

Neuromuscular Junction

Answer 6

Synapses between motor neurons and muscle fibers

Question 7

Neurotransmitter motor neurons release

Answer 7

Acetylcholine

Question 8

End plates

Answer 8

• Folds that fit around the terminal buttons
• Covered in nicotinic ACh receptors

Question 9

Segments of Myofibrils

Answer 9

• Shorter segments called sarcomeres
• Separated by Z lines

Question 10

Thick Filaments of Sarcomeres

Answer 10

Myosin

Question 11

Thin Filaments of Sacomeres

Answer 11

Actin

Question 12

Blockers that are on actin

Answer 12

Tropomyosin and troponin

Question 13

Monosynaptic

Answer 13

Only two neurons and one synapse is involved

Question 14

Lower Motor Neurons Location

Answer 14

Axons exit ventral horn and are bundled together into the ventral root

Question 15

Steps of Actions Potentials in Neuromuscular Junctions

Answer 15

1. Alpha motor neurons release acetylcholine into the neuromuscular junction
2. Motor end plate is covered in nicotinic acetylcholine receptors - let sodium in causing EPSPs and the cell reaches a threshold
3. Voltage-gated sodium ion channels open, cell depolarizes
4. Depolarization opens voltage gated calcium ion channels, and calcium enters the cell
5. calcium binds to tropomyosin and changes the shape of tropomyosin, sliding happens
6. Myosin uses ATP

Question 16

Interneurons

Answer 16

• Relay neurons
• connect sensory and motor neurons
• Create reciprocal innervation

Question 16

Upper Motor Neurons

Answer 16

Cell bodies in the brain and axons travel down the spinal cord and influence interneurons and lower neurons

Question 17

Infant Reflexes: Grasping

Answer 17

Touch to the palm causes fingers to close in a grasp

Question 18

Infant Reflexes: Rooting

Answer 18

Touch to cheek causes head turn and sucking

Question 19

Central Pattern Generators

Answer 19

Control Basic muscle sequences like walking

Question 20

Oscillator Circuiuts

Answer 20

Which control rhythmic back and forth motions like scratching or trilling your tongue

Question 21

Golgi (Tendon) Reflex

Answer 21

• Excessive force on tendons is sensed by golgi tendon organs
• Signals stimulate interneurons
• Interneurons send inhibitions to the same muscle
• Excitation to antagonistic muscle

Question 22

Antagonistic Pairs

Answer 22

Flexor and Extensors

Question 23

Flexors

Answer 23

Move bone towards the body

Question 24

Extensors

Answer 24

Move bone away from the body

Question 25

Reciprocal Innervation

Answer 25

- Sensory neuron stimulates motor neuron and interneuron - Motor neuron of extensor is excited - Interneuron sends inhibition to motor neuron of antagonistic flexor muscle

Question 26

Pain Withdraw Reflex

Answer 26

- Flexors are excited (pull limbs closer to body) - Extensors are inhibited (reciprocal innervation)