Chapter 13

Question 1

Somatic reflex

Answer 1

Reflexes that involve somatic motor neurons and skeletal muscles

Question 2

Autonomic reflexes

Answer 2

Reflexes whose responses are controlled in the autonomic neurons

Question 3

Spinal reflexes

Answer 3

Integrated in the spinal cord. These reflexes may be modulated by higher input from the brain but can occur without that input.

Question 4

Cranial reflex

Answer 4

Reflexes integrated in the brain

Question 5

Innate reflexes

Answer 5

Born with reflexes, genetically determined, example is the knee jerk, or patellar tendon reflex.

Question 6

Learned reflex

Answer 6

Acquired through experience. Dwight eating Altoids every time Jim pushes a button on the computer.

Question 7

Monosynaptic reflex

Answer 7

The simplest reflex. Named for the single synapse between the two neurons in the pathway

Question 8

Polysynaptic reflex

Answer 8

May be quite complex, with extensive branching into the CNS to form networks involving multiple inter neurons

Question 9

Alpha motor neuron

Answer 9

The somatic motor neurons that innervate skeletal muscle fibers.

Question 10

Extrafusal muscle fiber

Answer 10

The effectors are contractile skeletal muscle fibers. Action potentials in alpha motor neurons cause extrafusal fibers to contract .

Question 11

Muscle tone

Answer 11

Resistance to stretch even when the muscle is relaxed and at rest.

Question 12

Structure and function of the golgi tendon organ

Answer 12

A type of receptor found at the junction of tendons and muscle fibers, GTOs respond primarily to muscle tension created during the isometric phase of contraction. Relatively insensitive to muscle stretch

Question 13

Gamma motor neuron

Answer 13

Small neuron that innervates intrafusal fibers within the muscle spindle

Question 14

Intrafusal fiber

Answer 14

Modified muscle fibers of the muscle spindle that lack myofibrils in their central portions

Question 15

Muscle spindle

Answer 15

Muscle receptors that send information about muscle length

Question 16

Myotatic unit

Answer 16

Collection of synergistic and antagonistic muscles that act in a coordinated fashion to control a single joint

Question 17

How does a stretch reflex and reciprocal inhibition coordinate joint movement

Answer 17

When a muscle spindle is stretched and the stretch reflex is activated, the opposing muscle group must be inhibited to prevent it from working against the resulting contraction of the homonymous muscle.

The process of muscles on one side of a joint relaxing to accommodate contraction on the other side of the joint

Question 18

How can flexor and crossed extensor reflexes coordinate limb movements

Answer 18

?

Question 19

How flexion and crossed extensor reflex’s can coordinate movements

Answer 19

The crossed extensor reflex is contralateral, meaning the reflex occurs on the opposite side of the body from the stimulus. (Stepping on a nail and your other leg compensating all of the body weight as you lift the injured foot)

Question 20

Compare reflex, voluntary and rhythmic units

Answer 20

Reflex is an involuntary or automatic action in response to stimulus.

Voluntary movement is purposeful, goal directed movements. Initiated entirely from within the CNS, performance improves with practice, reflex and postural movements are often initiated that compensate for the effects of the intended action on other parts of the body.

Rhythmic movements a combination of reflex and volition. Initiation and termination is voluntary but the actual movement is more stereotyped (
Walking, running, chewing)

Question 21

Central pattern generator

Answer 21

Neuronal circuits that when activated can produce rhythmic motor patterns such as walking, breathing, flying, and swimming.

Question 22

Spinal cord— reflexes and locomotion

Answer 22

The central pattern generator provides the basic locomotor rhythm and synergies by integrating commands from various sources that serve to initiate or modulate its output to meet the requirements of the environment

Question 23

Brain stem and cerebellum — postural reflex, eye movement, hand movement

Answer 23

The cerebellum receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements.

Question 24

Cerebral cortex and basal ganglia— voluntary movement

Answer 24

?

Question 25

Phases of voluntary movement

Answer 25

Planning
Initiation
Execution

Question 26

Feedforward controls

Answer 26

Element or pathway within a control system that passes controlling signal from a source in its external environment to a load somewhere in its external environment

Question 27

Feedback control

Answer 27

A response within a system that influences the continued activity or productivity of that system. In essence it is the control of a biological reaction by the end products of that reaction

Question 28

Features of visceral muscle movement

Answer 28

Involuntarily controlled
Not striated
Not branched
And singly nucleated

Controlled by the autonomic and enteric nervous systems .