Control of Movement

Question 1

flexion vs. extension

Answer 1

flexion:
A movement of a limb that tends to bend its joints; opposite of extension.

extension:
A movement of a limb that tends to straighten its joints; the opposite of flexion

Question 2

isometric vs. isotonic

Answer 2

Isometric movement: Maintaining limb position while changing muscle tension

Isotonic movement: Changing limbe position without changing muscle tension

Question 3

Extrafusal muscle fiber, intrafusal motor fiber

Answer 3

-extrafusal muscle fiber
Muscle fibers that are responsible for the force exerted by contraction of a skeletal muscle.

-intrafusal motor fiber
A muscle fiber that functions as a stretch receptor, arranged parallel to the extrafusal muscle fibers, thus detecting changes in muscle length.

Question 4

alpha motor neuron

Answer 4

alpha motor neuron
A neuron whose axon forms synapses with extrafusal muscle fibers of a skeletal muscle; activation contracts the muscle fibers.


Question 5

gamma motor neuron

Answer 5

gamma motor neuron

A neuron whose axons form synapses with intrafusal muscle fibers.

Question 6

motor unit

Answer 6

A motor neuron and its associated muscle fibers.

Question 7

myofibril

Answer 7

An element of muscle fibers that consists of overlapping strands of actin and myosin; responsible for muscular contraction

Question 8

actin/myosin

Answer 8

One of the proteins (with actin) that provide the physical basis for muscular contraction.

Question 9

stated muscle

Answer 9

Skeletal muscle; muscle that contains striations.


Question 10

neuromuscular junction

Answer 10

The synapse between the terminal buttons of an axon and a muscle fiber.


Question 11

motor endplate

Answer 11

The postsynaptic membrane of a neuromuscular junction

Question 12

endplate potential

Answer 12

The postsynaptic potential that occurs in the motor endplate in response to release of acetylcholine by the terminal button. [therefore contraction]

Question 13

smooth muscle

Answer 13

Nonstriated muscle innervated by the autonomic nervous system; found in the walls of blood vessels, in the reproductive tracts, in sphincters, within the eye, in the digestive system, and around hair follicles.


Question 14

cardiac muscle

Answer 14

muscle for heart contractions, non skeletal

Question 15

monosynaptic stretch reflex

Answer 15

A reflex in which a muscle contracts in response to its being quickly stretched; involves a sensory neuron and a motor neuron, with one synapse between them. (dropping weight muscle lengthens, increase firing MS affront, alpha motor, strength of contraction increased))

Question 16

clasp knife reflex

Answer 16

A reflex that occurs when force is applied to flex or extend the limb of an animal showing decerebrate rigidity; resistance is replaced by sudden relaxation. This is due to inhibition from golgi tendon organs that inhibits muscle contraction

Question 17

Posture adjustment

Answer 17

when we lean forward, muscle lengthens (MS fire, alpha motor stimulated) which leads to contraction which pushes toes down and therefore we lean back

Question 18

somatotopic orginization

Answer 18

A topographically organized mapping of parts of the body that are represented in a particular region of the brain.


Question 19

supplemental motor area

Answer 19

A region of association motor cortex of the dorsal and dorsomedial frontal lobe, rostral to primary motor cortex.


Question 20

premotor area

Answer 20

gion of motor cortex of the lateral frontal lobe,

Question 21

The “transcortical reflex”


Answer 21

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A long-latency EMG response to muscle stretch or cutaneous stimulation that depends on rapid transmission of the sensory volley and evoked motor volley and involves the cerebral cortex. Also known as a long loop reflex.

Question 22

Sensorimotor reciprocity 
(a realistic model)

Answer 22

?
attention is organized by intention (intention drives attention which controls action)
long fibres interconnect front/back of association cortex, short give immediate feedback

Question 23

fastigial nucleus

Answer 23

A deep cerebellar nucleus; involved in the control of movement by the reticulospinal and vestibulospinal tracts.


Question 24

interposed nucleus

Answer 24

A set of deep cerebellar nuclei; involved in the control of the rubrospinal system.

Question 25

pontine nucleus

Answer 25

serves as an important source of input to the cerebellum.


Question 26

dentate nucleus

Answer 26

A deep cerebellar nucleus; involved in the control of rapid, skilled movements by the corticospinal and rubrospinal systems.


Question 27

mesencephalic locomotor region

Answer 27

A region of the reticular formation of the midbrain whose stimulation causes alternating movements of the limbs normally seen during locomotion.