Unit 2-2

Question 1

Movement

Answer 1

Contractions of muscles that provide our means of interacting with world

Question 2

Reflex

Answer 2

Simple, unvarying, unlearned responses to sensory stimuli such as pain, touch, and pressure

Question 3

Act

Answer 3

Complex behaviors that are composed of multiple movements in a sequence

Question 4

Motor pathways (3)

Answer 4

1. Motor cortex receives info from other cortical areas and sends commands to the thalamus and Brainstem
2. Cerebellum and basal ganglia adjust the commands received from other parts of the motor control system
3. Brainstem passes commands from cortex to spinal cord

Question 5

Components of neuromuscular system (6)

Answer 5

1. Skeletal system (determine which movements are possible
2. Spinal cord (controls skeletal muscles)
3. Brainstem (transmits commands to spinal cord)
4. Primary motor cortex (some main commands for action initiated)
5. Non primary motor cortex (provide additional source of motor commands)
6. Cerebellum, basal ganglia, thalamus (modulate activities of control system)

Question 6

Feedback

Answer 6

From senses inform and fine tune movements

Question 7

Skeletal muscles

Answer 7

Voluntary movements

Question 8

Skeletal muscles Antagonist

Answer 8

Pull bone in opposite direction

Question 9

Skeletal muscle synergists

Answer 9

Work together

Question 10

Motor neurons synapse on muscles (5)

Answer 10

1. Motor neurons descend from spinal cord to skeletal muscles
2. Form synapses with neuromuscular junctions
3. Release acetylcholine
4. Binding of Ach triggers muscle contraction
5. Muscle unit (motor neuron and muscles it innervates)

Question 11

Two types of proprioceptors

Answer 11

Muscle spindles and golgi tendon organs

Question 12

Muscle spindles

Answer 12

Buried within muscle fibers, contains sensory neurons that are responsive to stretch

Question 13

Golgi tendon organs

Answer 13

Send sensory info from tendons and or sensitive to tension

Question 14

Pyramidal system (corticospinal system)

Answer 14

• involves cortex communicating with somatic nerves
• passes through medulla, fibers form pyramid shape
• fibers descend through ventral horn of the spinal cord

Question 15

Extra pyramidal system

Answer 15

• does not pass through medulla
• Composed of regulatory areas, such as the basal ganglia and cerebellum
• regulation and fine-tuning of voluntary movement and reflexes

Question 16

Primary motor cortex (m1)

Answer 16

• located in Precentral gyrus
• m1 neurons most active before movement begins, directionally tuned
• map movements

Question 17

Plasticity

Answer 17

Ability for brain to change with experience

Question 18

Nonprimary motor cortex

Answer 18

• composed of supplementary motor area (SMA) and premotor cortex
• maps behaviors

Question 19

supplementary motor area (SMA)

Answer 19

Initiation of movement through internal planning)

Question 20

Premotor cortex

Answer 20

Motor sequences determined by external events (areas, organized into categories; defensive movements; feeding behaviors)

Question 21

Mirror neurons

Answer 21

• located in premotor cortex
• active when tracking same movements made by others

Question 22

Basal ganglia

Answer 22

• Cortex -> thalamus -> basal ganglia -> thalamus -> cortex (loops)
• help control amplitude, direction, and initiation of movement
• role is the modulation of movement initiating elsewhere (especially by memory)

Question 23

Cerebellum

Answer 23

• receives sensory input from proprioceptors. vestibular system, and visual system, pyramidal/ extrapyramidal systems
• important for skilled movements, including repeated movements that become automatic

Question 24

Plegia (paralysis) and paresis (weakness) (pyramidal)

Answer 24

Strokes in motor areas

Question 25

Apraxia (pyramidal)

Answer 25

- Damage to planning areas in frontal cortex - inability to carry out complex behaviors, even though no neuromuscular defect is evident

Question 26

Spinal injuries (pyramidal)

Answer 26

Results in immediate and permanent paralysis, and loss of sensation below the injury

Question 27

Ataxia (extrapyramidal)

Answer 27

- Damage to cerebellum - loss of coordination of the legs

Question 28

Decomposition of movement (extrapyramidal)

Answer 28

Complex behaviors are broken down into composite parts, rather than being smooth and cohesive

Question 29

Extra pathology of extrapyramidal

Answer 29

Difficulty maintaining gaze or tracking movement visually

Question 30

Parkinson’s and Huntington’s (extrapyramidal)

Answer 30

Diseases of the basal ganglia

Question 31

Parkinson’s disease

Answer 31

- Damage to dopaminergic neurons of the substantia nigra - Slowed movements, tremors, fewer facial expressions, few spontaneous actions

Question 32

Huntington’s disease

Answer 32

- Widespread damage and basal ganglia, including caudate nucleus and putamen - involuntary movements, such as muscle, jerking and body, riding, in ability to control the eyes, intellectual deterioration