Chapter 11 terms

Question 1

Spinal animals

Answer 1

The spinal cord is disconnected from the brain.

Question 2

Reflex

Answer 2

Simple unvarying, and unlearned response to sensory stimuli such as touch, pressure and pain. Basic unit of movement

Question 3

Motor plan

Answer 3

a set of muscle commands established before the action occurs.

Question 4

Electromyography (EMG)

Answer 4

records the electrical activity of muscles.

Question 5

Closed-loop control mechanisms

Answer 5

These mechanisms maximize accuracy, information from what is being controlled flows back into the controlling device.

Question 6

Open-loop control mechanism

Answer 6

This mechanism maximizes speed. There is no external feedback, and the activity is pre-programmed. Used for ballistic movements.

Question 7

Ballistic movements

Answer 7

are rapid-completed no matter what sensory feedback is received.

Question 8

Hierarchy of Motor control systems:

Answer 8

Cerebellum and basal ganglia, Nonprimary motor cortices, primary motor cortex, brainstem, spinal cord, skeletal system

Question 9

Skeletal system

Answer 9

Bones and their attached muscles

Question 10

Spinal cord

Answer 10

Controls skeletal muscles

Question 11

Brain stem

Answer 11

Integrates motor commands and relays sensory information

Question 12

Primary motor cortices

Answer 12

Provides an additional source of motor commands, acting indirectly via primary motor cortex and through direct connections to lower levels of the motor hierarchy

Question 13

Cerebellum and basal ganglia

Answer 13

modulate activities of these control systems, sometimes via the thalamus in a loop back to the cortex.

Question 14

Smooth muscle

Answer 14

Found in the heart and stomach. Is controlled by the autonomic nervous system.

Question 15

Tendons

Answer 15

Connect muscle to bone

Question 16

Antagonists

Answer 16

Muscles that contract when others extend

Question 17

Synergists

Answer 17

Muscles that act together

Question 18

Motor neurons

Answer 18

transmit motor messages to muscles.

Question 19

Muscle fiber

Answer 19

Skeletal muscle is composed of this This thing is made of myosin and actin

Question 20

Myosin

Answer 20

Thick filaments

Question 21

Actin

Answer 21

thin filaments

Question 22

Striated muscle

Answer 22

Overlapping gives this type of muscle a striped appearance

Question 23

Fast- twitch muscle fibers

Answer 23

Muscle fibers that contract rapidly but fatigue easily.

Question 24

Slow-twitch muscle fibers

Answer 24

These muscle fibers contract more slowly but are resistant to fatigue (mainly postural muscles).

Question 25

Muscular dystrophy (MD)

Answer 25

refers to disorders that lead to degeneration and changes in muscle structure.

Question 26

Dystrophin

Answer 26

A protein needed for normal muscle function- produced by a gene on the X chromosomes.

Question 27

Acetylcholine

Answer 27

When action potentials travel downt he motor neuron, which branches into many terminals near its target where this neurotransmitter

Question 28

neuromuscular junctions

Answer 28

These targets where the neuron terminates on the muscle fiber are called this.

Question 29

A motor unit

Answer 29

this consists of a single motor neuron and all muscle fibers it innervates

Question 30

Innervation ratio

Answer 30

the number of fibers innervated by an axon.

Question 31

Myasthenia

Answer 31

a disease where the patient develops antibodies to his own ACh

Question 32

Proprioception

Answer 32

The collection of information about body movements and positions

Question 33

Proprioceptive receptors

Answer 33

Muscle spindles and Golgi Tendon organs

Question 34

Muscle spindles

Answer 34

consist of afferent and efferent nerve. They detect the length of the muscle

Question 35

Intrafusual fibers

Answer 35

These fibers lie within each muscle spindle

Question 36

Extrafusal Fibers

Answer 36

These fibers lie outside of the muscle spindles

Question 37

Primary sensory ending

Answer 37

wrap the center of the intrafusal fiber and secondary sensory endings wrap the ends of the spindle. These endings a maximally sensitive early in a stretch; communicate velocity

Question 38

Secondary sensory endings

Answer 38

These endings are slow to change rate, maximally sensitive to maintain length; communicate muscle length.

Question 39

Gamma motoneurons

Answer 39

alter tension within the spindle and control receptor sensitivity.

Question 40

Alpha motoneurons

Answer 40

go to the extrafusal muscle fibers.

Question 41

Golgi tendon organs

Answer 41

This thing is responsive to muscle contraction but not to stretch. Stimulation of this thing inhibits motor neurons acting on muscles, thereby relaxing tension and preventing damage.

Question 42

Central pattern generator

Answer 42

the neural circuitry responsible for rhythmic behavior such as walking

Question 43

Polio viruses

Answer 43

Destroy spinal motoneurons and sometimes cranial motoneurons

Question 44

Amyotrophic lateral sclerosis (ALS

Answer 44

Degeneration of motoneurons and the subsequent loss of their target muscles.

Question 45

Pyramidal system

Answer 45

Consists of neuronal cell bodies in the cerebral cortex and their axons, which for the pyramidal tract to the spinal cord.

Question 46

Nonprimary motor cortex

Answer 46

This lies anterior to M1 and has two main regions: the supplementary motor area, and premotor cortex

Question 47

Mirror neurons

Answer 47

These neurons are active both when an individual makes a particualr movement and when an individual sees another individual make that same movement.

Question 48

Extrapyramidal system

Answer 48

includes motortracts that do not run through the medulla.

Question 49

Spasticity

Answer 49

increased rigidity in response to forced limb movement.

Question 50

Apraxia

Answer 50

Inability to carry out movements, although no muscle paralysis.

Question 51

Ideomotor apraxia

Answer 51

inability to complete simple motor activity on command.

Question 52

Ideational Apraxia

Answer 52

Impairment in completing a sequence oft asks although able to do each individual step.