Muscular, Skeletal, And Nervous Systems

Question 1

Agonist

Answer 1

The muscle initiating a desired movement - the muscle that is most directly involved in causing movement
*muscle that is shortening to perform concentric action
Example : bicep during bicep curls

Question 2

Antagonist

Answer 2

The opposite of agonist - the muscle being stretched
Can stop or slow down movement caused by the agonist
Example: the triceps during a bicep curl

Question 3

Contractability

Answer 3

Unique ability of a muscle to shorten, produce tension at its endpoints, or do both

Question 4

Concentric action

Answer 4

Occurs when the muscle overcomes a load and shortens

Example : upward phase of a bicep curl

Question 5

Eccentric action

Answer 5

Occurs when muscle cannot develop sufficient tension and is overcome by an external load (progressively lengthens)
-commonly involved in deceleration of joint motion

Question 6

Isometric action

Answer 6

The muscle generates force against a resistance but does not overcome it and therefore doesn’t shorten, lengthen or cause joint motion (no movement occurs)
Many of the body’s posture muscles work isometric ally to hold or restrain the skeleton upright opposing the force of gravity

Question 7

Isokinetic

Answer 7

Dynamic muscle action kept at a constant velocity independent of the amount of muscular force generated by the involved muscles
The speed of shortening and lengthening is constant
The joint moves through a range of motion at a constant velocity

Question 8

Muscle fiber

Answer 8

The structural component of skeletal muscles
Also known as the muscle cell

Cylindrical cell that contains hundreds of nuclei, varies in length

Question 9

Endomysium

Answer 9

Layer of Connective tissue surrounding the individual muscle fiber and thus separating the fibers from one another

Question 10

Fascicles

Answer 10

Bundles of muscle fibers - contain up to 150 fibers

Question 11

Perimysium

Answer 11

Connective tissue surrounding fasciculus

Question 12

Epimysium

Answer 12

Connective tissue that Encases the entire muscle
An outer fascia

Joins with the other intramuscular tissues to form strong connective tissue of tendons

Question 13

Periosteum

Answer 13

Outermost covering of the bone to which the tendons attach

Question 14

Sarcoplasm reticulum

Answer 14

Highly specialized complex that stores calcium ions

Question 15

Myofibrils

Answer 15

Element of skeletal muscle that allow the muscle to contract

Consist of two proteins actin (thinner) and myosin (thicker) (referred to as myofilaments)