Chapter 1 (Muscles)

Question 1

Muscle characteristics

Answer 1

• Voluntarily or involuntarily controlled
• Striated or unstriated
• Somatic or visceral

Question 2

Types of muscles

Answer 2

• Skeletal striated muscle
• Cardiac striated muscle
• Smooth muscle

Question 3

Skeletal striated muscle

Answer 3

Produces movement through shortening or controlled relaxation or to maintain position against gravity

Question 4

Cardiac striated muscle

Answer 4

Pumps blood from the heart via continuous rhythmic contraction

Question 5

Smooth muscle

Answer 5

Propels substances and restrict flow

Question 6

Functions of skeletal muscles

Answer 6

• Provide movement
• Static support
• Give form to the body
• Provide heat

Question 7

Skeletal muscles may be named based on:

Answer 7

• Function
• Bones which the muscles are attached to
• Position
• Length

Question 8

What happens during muscle contractions?

Answer 8

One of its attachments remain fixed while the other attachment is pulled toward it, resulting in movement

Question 9

What are attachments described as?

Answer 9

Origin and insertion

Question 10

Origin

Answer 10

Remains fixed during muscle contraction, often at the proximal end of the muscle

Question 11

Insertion

Answer 11

Moveable attachment, usually at the distal end of the muscle

Question 12

Types of muscle contractions

Answer 12

Reflective contraction and tonic contraction

Question 13

Reflective contraction

Answer 13

• Automatic, involuntary contraction

Question 14

Tonic contraction

Answer 14

• Even when relaxed, muscles are always in a state of slight contraction, otherwise known as muscle tone or tonus
• Gives muscle its firmness, assisting in the stability of joints, maintenance of posture, and keeping it muscle ready to respond to stimuli

Question 15

Two types of phasic contraction

Answer 15

Isotonic contraction and isometric contraction

Question 16

Isometric contraction

Answer 16

Muscle length remains the same with no movement occurring. Muscle tension is above tonic levels to resist gravity or other forces

Question 17

Isotonic contraction

Answer 17

Muscle changes in length in relationship to the production of movement

Question 18

Two types of isometric contraction

Answer 18

Concentric. and eccentric

Question 19

Concentric

Answer 19

Movement occurs as a result of muscle shortening

Question 20

Eccentric

Answer 20

Contracting muscle lengthens in a controlled and gradual relaxation while exerting a diminishing force

Question 21

A functional unit of a muscle consists of?

Answer 21

A motor neuron and the muscle fibers it controls

Question 22

Phasic contraction results from

Answer 22

The activation of an increasing number of motor units above the level required to maintain a tonic contraction

Question 23

Function of muscles

Answer 23

• Agonist
• Antagonist
• Fixator
• Synergist

Question 24

Agonist

Answer 24

Primary muscle responsible for producing a specific movement of the body, contracting concentrically to produce the desired movement

Question 25

Antagonist

Answer 25

Opposes the action of another muscle, contracting eccentrically relaxing progressively in coordination to produce a smooth movement

Question 26

Fixator

Answer 26

Helps steady the proximal parts of a limb through isometric contraction while movements are occurring distally

Question 27

Synergist

Answer 27

Assist antagonist muscle either directly to assist with the same movement or indirectly as a fixator of intervening joints

Question 28

Nerves supplying skeletal muscles enter through the ____ ___ as opposed to the _____

Answer 28

Muscle bellies/ tendons

Question 29

Supplying nerves are often located _______ it innervates to help protect the nerve from injury

Answer 29

Deep of the muscle

Question 30

Arteries supply the muscle structures they are

Answer 30

In contact with

Question 31

What happens in the absence of muscle tone?

Answer 31

May allow joints to be dislocated as a patient is being lifted or positioned

Question 32

What happens in the absence of normal tonus?

Answer 32

The antagonist muscle may cause a limb to assume abnormal resting positions