Chapter 5 Muscular System

Question 1

Proximal attachment

Answer 1

Origin (reverse muscle action if moves toward insertion)

Question 2

Distal Attachment

Answer 2

Insertion (normally moves toward origin)

Question 3

Parallel Muscle Fibers

Answer 3

Strap - long, thin fibers run entire length (ex. sartorius)
Fusiform - spindle shape (ex. biceps)
Rhomboidal - four sides, flat (ex. rhomboids)
Triangular - flat, fan shaped (ex. pec major)

Question 4

Oblique

Answer 4

Pennate = feather
Unipennate - one side of a feather (ex. tibialis anterior)
Bipennate - reg feather (ex. gastrocnemius)
Multipennate - many tendons (ex. delts)

Question 5

Active Insufficiency

Answer 5

Muscle can’t shorten any further. Occurs at agonist. (ex.hamstrings in ppt)

Question 6

Passive Insufficiency

Answer 6

When a muscle can’t be stretched any farther. Occurs at antagonist. (ex. hamstrings ppt)

Question 7

Tenodesis

Answer 7

Allowing muscle function where function no longer exists.

Question 8

Excursion

Answer 8

The difference between the length of a stretched muscle and contracted muscle

Question 9

Irritability

Answer 9

Ability to respond to a stimulus

Question 10

Contractility

Answer 10

Ability to shorten or contract

Question 11

Extensibility

Answer 11

Ability of a muscle to stretch or lengthen when force applied

Question 12

Elasticity

Answer 12

Ability to recoil after stretching or shortening

Question 13

Tension

Answer 13

Force built up within a muscle

Question 14

Isometric

Answer 14

Muscle contracts without changing length

Question 15

Concentric

Answer 15

Muscle contracts (against gravity)

Question 16

Eccentric

Answer 16

Muscle contracts while lengthening (with gravity)

Question 17

Isotonic

Answer 17

Fixed resistance

Question 18

Isokinetic

Answer 18

Fixed rate

Question 19

Agonist

Answer 19

Prime mover, muscle or muscle group that causes the motion (ex. Elbow flexion - Bicep = agonist, Pronator teres = assisting mover)

Question 20

Antagonist

Answer 20

Muscle that performs the opposite motion of the agonist (ex. Elbow flexion - Biceps = agonist, Triceps = antagonist)

Question 21

Cocontraction

Answer 21

When agonist and antagonist contract at the same time (occurs when there is a need for accuracy)

Question 22

Stabilizer

Answer 22

Muscle that supports or makes firm, a part and allows the agonist to work more efficiently (ex. Doing a push-up, Agonist = triceps, elbow extensors, Stabilizers = abs)

Question 23

Neutralizer

Answer 23

Prevents unwanted motion and may also allow a muscle to do more than one motion (ex. biceps flex the elbow and supinate the forearm)

Question 24

Synergist

Answer 24

Muscle that works with another muscle to enhance a particular motion

Question 25

Angle of Pull

Answer 25

Muscles know one direction of pull, visualizing the muscle will assist you in knowing their action (Vertical, horizontal, diagonal)

Question 26

Closed Kinetic Chain

Answer 26

Weight bearing, proximal segments move (o -> i )

Question 27

Open Kinetic Chain

Answer 27

Non- wieght bearing, distal segment is free to move ( i -> o)