Muscles Key Terms

Question 1

Action Potential

Answer 1

The function of all nerve cells is to transmit electrical signals.

Question 2

Agonist

Answer 2

A classification used to describe a muscle that causes specific movement or possibly several movements to occur through the process of its own contraction.

Question 3

Antagonist

Answer 3

A classification used to describe a muscle that acts in opposition to the specific movement generated by the agonist and is responsible for returning a limb to its initial position

Question 4

Autonomic Nervous System (ANS) (or visceral nervous system)

Answer 4

The part of the peripheral nervous system that acts as a control system, therefore, maintaining homeostasis in the body

Question 5

Cardiac Muscle

Answer 5

A type of involuntary striated muscle found in the walls of the heart. As it contracts, it propels blood into the heart and through the blood vessels of the circulatory system

Question 6

Central Nervous System (CNS)

Answer 6

Comprised of the brain and spinal cord and acts as the hard drive of the body processing and storing information and selecting responses

Question 7

Collateral Ligaments

Answer 7

These ligaments are found on the lateral and medial aspects of the synovial joints. They are also called capsular ligaments.

Question 8

Concentric Contraction

Answer 8

Occurs while the muscle is going from a state of rest into a shortened position

Question 9

Dorsal Ligament System

Answer 9

This group of ligaments provides support for the axial skeleton

Question 10

Eccentric Contraction

Answer 10

Occurs as the shortened muscle returns to a lengthened state under control (some fibers remain in contraction until the muscle returns to rest to prevent abrupt motion that could damage tissue).

Question 11

Endomysium

Answer 11

A layer of connective tissue that ensheaths a muscle fiber and is composed mostly from reticular fibers

Question 12

Epimysium

Answer 12

A layer of connective tissue which ensheaths the entire muscle

Question 13

Fascia

Answer 13

The soft tissue component of the connective tissue system that permeates the human body. It interpenetrates and surrounds muscles, bones, organs, nerves, blood vessels and other structures

Question 14

Golgi Tendon Organ (GTO)

Answer 14

It is found in the musculotendinous junction where the two tissues interface. It specifically measures the tension or amount of load on a muscle so that it can trigger the muscle to shut-down in the face of overload.

Question 15

Insertion

Answer 15

The insertion of a muscle (a moving attachment) is the opposite end of the muscle. This definition means that there is a functional aspect to the definition of a muscle’s origin and insertion

Question 16

Intercellular Fluid

Answer 16

Between the cells of the body exists a fluid matrix of proteins and lipids in a solution of water and salts

Question 17

Isometric Contraction

Answer 17

Occurs when muscles contract and does not produce movement of bones. Isometric contraction occurs when a muscle contracts but does not bring its bony attachments closer together as in carrying a box

Question 18

Isotonic Contraction

Answer 18

Occurs when muscles contract to produce movement of bones. Isotonic contractions can be either concentric or eccentric, although these two typically happen one after the other

Question 19

Joint

Answer 19

A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally

Question 20

Ligament

Answer 20

Strong strips of fibrous connective tissue that hold bones together at joints, thereby stabilizing the skeleton during movement.

Question 21

Muscle Spindle Fiber (MSF)

Answer 21

A bundle of several fibers that are both muscle and nerve in origin. Because of its unique physiology, the MSF can measure the rate and degree of a muscle contraction.

Question 22

Origin

Answer 22

The origin of a muscle (a fixed anchor) is the point at which it attaches to a bone (usually) or another muscle. The structure that the origin is attached to is not moved by the contraction of the muscle

Question 23

Perimysium

Answer 23

A sheath of connective tissue which groups individual muscle fibers (anywhere between 10 to 100 or more) into bundles or fascicles

Question 24

Peripheral Nervous System (PNS)

Answer 24

Resides or extends outside the central nervous system (CNS) and is responsible for the collection of information or stimuli

Question 25

Skeletal Muscle

Answer 25

Is soft tissue anchored by tendons to bone and is used to affect skeletal movement such as locomotion and in maintaining posture

Question 26

Skeleton

Answer 26

A strong and often a rigid framework that supports the body of an animal, holding it upright and giving it shape and strength

Question 27

Smooth Muscle

Answer 27

Is a soft tissue found within the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels, and skin

Question 28

Synergist

Answer 28

A kind of muscle which performs, or assists in performing, the same set of joint motion as the agonists or “prime movers”. Synergists are muscles that act on movable joints

Question 29

Tendon

Answer 29

A tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension