8.1.1 The Control Of Movement 2

Question 1

____ control movement. A proprioceptor is a receptor that detects the position or movement of a part of the body – in these cases a muscle.

Answer 1

Proprioceptors

Question 2

Muscle proprioceptors detect the ____ and ____ of a muscle and send messages that enable the spinal-cord to adjust its signals.

Answer 2

stretch and tension

Question 3

When a muscle is stretched, the spinal-cord sends a reflexive signal to contract it. This ____ ____ is caused by a stretch; it does not produce one.

Answer 3

stretch reflex

Question 4

One kind of proprioceptor is the ____ ____, a receptor parallel to the muscle that responds to stretch.

Answer 4

muscle spindle

Question 5

Whenever the muscle spindle is stretched, it’s sensory nerve sends a message to a ____ ____ in the spinal-cord, which in turn sends a message back to the muscles surrounding the spindle, causing a contraction.

Answer 5

motor neuron

Question 6

____ ____ ____, also proprioceptors, respond to increases in muscle tension. Located in the tendons at opposite ends of a muscle, they act as a brake against an excessively vigourous contraction.

Answer 6

Golgi tendon organs

Question 7

Some muscles are so strong that they could ____ themselves if too many fibres contracted at once. Golgi tendon organs detect the tension that results during a muscle contraction. Their impulses travel to the spinal-cord, where they excite interneurons that inhibit the motor neurons.

Answer 7

damage

Question 8

In short, a vigorous muscle contraction ____ further contraction by activating the Golgi tendon organs.

Answer 8

inhibits

Question 9

The proprioceptors not only control important reflexes but also provide the ____ with information.

Answer 9

brain

Question 10

Different kinds of movement depend on different kinds of control by the ____ ____.

Answer 10

nervous system

Question 11

____ are consistent automatic responses to stimuli. We generally think of reflexes is involuntary because they are insensitive to reinforcements, punishment, and motivations.

Answer 11

Reflexes

Question 12

Even when a ____ to a stimulus is not a reflex, it differs from a spontaneous behaviour.

Answer 12

reaction

Question 13

When you react to a stimulus, you move faster than when your action is ____.

Answer 13

spontaneous

Question 14

If you place an object firmly in an infants hand, the infant grasps it (the ____ reflex). If you stroke the sole of the foot, the infant extends the big toe and fans the others (the ____ reflex). If you touch an infants cheek, the infant turns toward the stimulated cheek and begins to suck (the ____ reflex).

Answer 14

grasp : Babinski : rooting

Question 15

A ____ missile is launched like a thrown ball: once it is launched, no one can change its aim. A guided missile detects the target and adjust its trajectory to correct its aim.

Answer 15

ballistic

Question 16

Some movements are ballistic, and others are corrected by feedback. ____ ____ is executed as a whole: once initiated, it cannot be altered. Reflexes are ballistic.

Answer 16

Ballistic movement

Question 17

Many of our behaviours consist of rapid sequences, as in speaking, writing, dancing, or playing a musical instrument. Some of these sequences depend on ____ ____ ____ – mechanisms in the spinal-cord that generate rhythmic patterns of motor output.

Answer 17

central pattern generators

Question 18

Although a stimulus may activate a central pattern generator, it does not control the ____ of the alternating movements.

Answer 18

frequency

Question 19

A fixed sequence of movements is called a ____ ____.

Answer 19

motor program

Question 20

Once began, the sequence is ____ from beginning to end.

Answer 20

fixed

Question 21

____ have built in motor programs. Yawning is an example. Certain facial expressions are also programmed, such as smiles, frowns, and the raised eyebrow greeting.

Answer 21

Humans