ch 2 Q&A

In the context of muscle action, a(n) _____ contraction occurs when tension is developed within the muscle but the joint angles remain constant.

isometric

Proprioceptors in combination with the other sense organs of the body are vital in _____, which is the conscious awareness of the position and movement of the body in space.

kinesthesis

rom a functional and historical perspective, the _____ part of the muscle is its origin.

least movable

For most of the skeletal muscles, _____ is a very useful way to determine muscle action, but it is limited to superficial muscles.

palpation

_____ muscles are categorized on the basis of the exact arrangement between the fibers and the tendon.

pennate

Some agonist muscles that are able to contribute significantly more to a joint movement than other agonists are known as _____.

prime movers

From a structural perspective, the _____ of the body is considered to be the origin.

proximal attachment of a muscle that attaches closest to the center

In the context of muscle terminology, fascial tissue forms a(n) _____ to retain tendons close to the body.

retinaculum

Every muscle fiber is innervated by a _____, which, when an appropriate stimulus is provided, results in a muscle contraction.

somatic motor neuron

In the context of neural control of voluntary movement, which of the following is the most specific level of control in the central nervous system?

spinal cord

Which of the following muscles surrounds a joint or body part and contracts to fixate the area to enable another limb or body segment to exert force and move?

stabilizers

In the context of muscle terminology, _____ are tough yet flexible bands of fibrous connective tissue that connect muscles to bones and other structures.

tendons

True or False: There are over 600 skeletal muscles, which constitute approximately 40% to 50% of body weight.

true

Which of the following types of muscles contracts to prevent an undesired joint action of the agonist and has no direct effect on the agonist action?

true synergists

_____ is a type of dynamic exercise usually using concentric or eccentric muscle contractions

Isokinetics

In the context of muscle action, which of the following is an accurate statement about a concentric contraction?

It involves the muscle developing active tension as it shortens.

Identify the muscles that counteract the action of other muscles to prevent undesirable movements such as inappropriate muscle substitutions.

Neutralizer muscles

Action is the specific movement of a joint resulting from a _____ contraction of a muscle that crosses the joint.

concentric

Biceps brachii that has the action of flexion at the elbow is an example of _____ contraction.

concentric

In the context of muscle tissue properties, contractility is the ability of muscle to _____.

develop internal force against resistance when stimulated

In the context of muscle action, _____ contractions occur when the musclegradually lessens in tension to control the descent of the resistance.

eccentric

true or false: Generally, pennate muscles produce a greater range of movement than similar-size muscles with a parallel arrangement.

false. Parallel muscles produce a greater range of movement than similar-size muscles with a pennate arrangement.

In the context of muscles, _____ occur when two or more forces are pulling in different directions on an object, causing the object to rotate about its axis.

force couples

In the context of muscle terminology, the _____ is the central, fleshy portion of the muscle.

gaster

In the context of muscle terminology, the contractile portion or the gaster generally _____ as the muscle contracts.

increases in diameter

In the context of muscle terminology, _____ occurs in the segment of the nervous system responsible for providing a stimulus to muscle fibers within a specific muscle.

innervation

Extensibility

Ability of muscle to be passively stretched beyond its normal resting length

Elasticity

Ability of muscle to return to its original resting length following stretching

efferent nerves

Also called motor nerves; nerves that carry information out of the brain and spinal cord to other areas of the body.

afferent nerves

Also called sensory nerves; nerves that carry information about the external environment to the brain and spinal cord via sensory receptors.

In the context of parallel muscles, identify an example of fusiform muscle.

Brachialis

______are the two major types of fiber arrangements that group all skeletal muscles

Parallel and pennate

Irritability

Sensitive or responsive to chemical, electrical, or mechanical stimuli

In the context of muscle terminology, identify a case wherein two muscles share a common tendon.

The Achilles tendon of the gastrocnemius and soleus muscles

Identify an example of intrinsic muscles.

The small muscles found entirely within the hand

Which of the following statements is true of stabilizers?

They are essential in establishing a relatively firm base for the more distal joints to work from when carrying out movements.

Which of the following statements is true of stabilizers?

They help another muscle move the joint in the desired manner and simultaneously prevent undesired actions.

rue or false: A particular nerve innervates only one muscle or portion of a muscle.

This is false. A particular nerve may innervate more than one muscle or portion of a muscle.

True or false: Isometric contractions may be thought of as dynamic contractions because the varying degrees of active tension in the muscles are causing the joint angles to change.

This is false. Isometric contractions may be thought of as static contractions, because a significant amount of active tension may be developed in the muscle to maintain the joint angle in a relatively static or stable position.

In the context of determination of muscle action, palpation is done by using the sense of touch to feel or examine _____.

a muscle as it contracts

Contractility

ability of muscle to contract and develop tension or internal force against resistance when stimulated

muscles working in a group rather than independently to achieve a given joint motion is known as______?

aggregate muscle action

In the context of muscle terminology, fascial tissue form a retinaculum to retain tendons close to the body in certain places throughout the body, such as _____.

around joints like wrist and ankle

Agonist muscles that contribute significantly less to the joint motion are commonly referred to as _____.

assistant movers

Unlike the extrinsic muscles, intrinsic muscles pertain usually to _____

muscles belonging solely to the body part on which they act

Each muscle cell is connected to a motor neuron at the _____.

neuromuscular junction

When only the supination action of the biceps brachii is desired, the triceps brachii contracts to counteract the flexion action of the biceps brachii. In the given action, the triceps brachii act as a(n) _____.

neutralizer