Sensorimotor Systems

Question 1

make up the majority of the human body’s tissues and are responsible for the movement of the body and the movement of materials within the body.

Answer 1

Muscles

Question 2

The human body contains somewhere between how many muscles?

Answer 2

640 and 850 muscles

Question 3

type of muscle found in the lining of the digestive tract, within arteries, and in the reproductive system.

Answer 3

Smooth muscle

Question 4

type of muscle named for its striped appearance.

Answer 4

Striated muscle

Question 5

produces the pumping action of the heart.

Answer 5

Cardiac muscle

Question 6

attached to bones produce the majority of body movement.

Answer 6

Skeletal muscle

Question 7

An individual muscle cell.

Answer 7

Muscle fiber

Question 8

The contraction of a single muscle fiber.

Answer 8

Twitch

Question 9

A long fiber strand running the length of a muscle fiber that is responsible for contraction.

Answer 9

Myofibril

Question 10

A boundary line for each sarcomere within a myofibril.

Answer 10

Z line

Question 11

A protein that makes up the thin filaments of the myofibril.

Answer 11

actin

Question 12

A protein that makes up the thick filaments of the myofibril.

Answer 12

myosin

Question 13

caused by the movement of the thick myosin filaments along the length of the thin actin filaments.

Answer 13

Muscle contractions

Question 14

A muscle fiber containing Type IIa or Type IIb myosin filaments that contains few mitochondria, uses anaerobic metabolism, and contracts rapidly; primarily responsible for movement requiring explosive strength.

Answer 14

Fast-twitch fiber

Question 15

A muscle fiber containing Type I myosin filaments and large numbers of mitochondria that contracts slowly using aerobic metabolism; primarily responsible for movement requiring endurance.

Answer 15

Slow-twitch fiber

Question 16

Type IIb fibers can contract up to how many times faster than Type I fibers?

Answer 16

ten times

Question 17

The average adult has approximately ____ amounts of fast- and slow-twitch muscles?

Answer 17

equal amounts

Question 18

Muscle enlargement occurs in response to muscle fiber damage. When fibers are damaged due to weightlifting or other strenuous activity, more actin and myosin filaments are produced.

Answer 18

Exercise on Muscle Formation and Sex differences

Question 19

A spinal motor neuron directly responsible for signaling a muscle fiber to contract.

Answer 19

alpha motor neuron

Question 20

A synapse formed between an alpha motor neuron axon terminal and a muscle fiber.

Answer 20

neuromuscular junction

Question 21

made up of a single alpha motor neuron and all the muscle fibers it innervates. A single motor unit includes either fast- or slow-twitch fibers but not a mixture of both.

Answer 21

motor unit

Question 22

The process of gradually activating more motor units as an increasing load is placed on a muscle.

Answer 22

Recruitment

Question 23

A sensory structure that provides feedback regarding muscle stretch. Each muscle spindle contains approximately a dozen intrafusal muscle fibers.

Answer 23

Muscle spindle

Question 24

One of the fibers outside the muscle spindle that is responsible for contracting the muscle.

Answer 24

Extrafusal muscle fiber

Question 25

A large, fast sensory axon that connects a muscle spindle to neurons in the spinal cord.

Answer 25

Ia sensory fiber

Question 26

tells the intrafusal fibers regarding accurate information about how far the muscle was stretched.

Answer 26

Gamma motor neurons

Question 27

A structure located in the tendons of muscles that provides information about muscle contraction.

Answer 27

Golgi tendon organ

Question 28

A small, slower, sensory axon that connects the Golgi tendon organs to neurons in the spinal cord.

Answer 28

Ib sensory fiber

Question 29

responsible for a number of reflex movements designed to protect us from injury, to maintain posture, and to coordinate the movement of our limbs.

Answer 29

spinal cord

Question 30

A spinal reflex that requires the action of only one synapse between sensory and motor neurons.

Answer 30

monosynaptic reflex

Question 31

A spinal reflex that requires interaction at more than one synapse.

Answer 31

polysynaptic reflex

Question 32

A polysynaptic spinal reflex that produces withdrawal of a limb from a painful stimulus.

Answer 32

flexion reflex

Question 33

lateral part of the spinal column, fine motor movements

Answer 33

Lateral pathway

Question 34

ventromedial part of the spinal column, automatic movements in the neck, torso, and portions of the limbs close to the body.

Answer 34

Ventromedial pathway

Question 35

inform the motor cortex about such factors as the direction, force, and timing required to carry out a skilled movement.

Answer 35

The Cerebellum

Question 36

participate in the choice and initiation of voluntary movements.

Answer 36

Basal Ganglia

Question 37

Motor area located in the gyrus rostral to the precentral gyrus; involved with managing complex sequences of movement.

Answer 37

Supplementary motor area (SMA)

Question 38

A motor area located in the gyrus rostral to the precentral gyrus; this area participates in holding a motor plan until it can be implemented.

Answer 38

Pre-SMA (supplementary motor area)

Question 39

a major disorder of the motor systems that causes autoimmune damage to the nicotinic ACh receptor.

Answer 39

Myasthenia gravis

Question 40

a major disorder of the motor systems that causes abnormalities in the gene that encodes for the protein dystrophin.

Answer 40

muscular dystrophy

Question 41

a major disorder of the motor systems that causes virus.

Answer 41

polio

Question 42

a major disorder of the motor systems that causes compression or laceration of the spinal cord.

Answer 42

accidental spinal cord damage

Question 43

a major disorder of the motor systems that causes possible link to genetic inheritance, possible link to viral infection.

Answer 43

Amyotrophic lateral sclerosis (ALS)

Question 44

a major disorder of the motor systems that causes possible link to exposure to toxins.

Answer 44

Parkinson’s disease

Question 45

a major disorder of the motor systems that causes abnormalities in the gene that encodes for the protein huntingtin.

Answer 45

Huntington’s disease