The Muscular System Intro

Question 1

are responsible for all types of body movement – they contract or shorten and are the machine of the body

Answer 1

Muscles

Question 2

Muscle – Latin: ___ “a muscle,” literally “little mouse,” diminutive of mus “mouse”

Answer 2

musculus

Question 3

Prefix myo refers to

Answer 3

muscle

Question 4

Prefix sarco refers to

Answer 4

flesh

Question 5

Muscle cells are elongated (muscle cell =

Answer 5

muscle fiber)

Question 6

Contraction of muscles is due to the movement of?

Answer 6

microfilaments

Question 7

What are the Three basic muscle types found in the body

Answer 7

• Skeletal muscle
• Cardiac muscle
• Smooth muscle

Question 8

*Skeletal Muscle Characteristics

Most are attached by

Answer 8

tendons to bones

Question 9

*Skeletal Muscle Characteristics
Cells are

Answer 9

multinucleate

Question 10

*Skeletal Muscle Characteristics
– have visible banding

Answer 10

Striated

Question 11

*Connective Tissue Wrappings of Skeletal Muscle

around single muscle fiber

Answer 11

Endomysium

Question 12

*Skeletal Muscle Characteristics
– subject to conscious control

Answer 12

Voluntary

Question 13

*Connective Tissue Wrappings of Skeletal Muscle

around a fascicle (bundle) of fibers

Answer 13

Perimysium

Question 14

*Connective Tissue Wrappings of Skeletal Muscle

covers the entire skeletal muscle

Answer 14

Epimysium

Question 15

*Connective Tissue Wrappings of Skeletal Muscle

on the outside of the epimysium

Answer 15

Fascia

Question 16

– cord-like structures

Answer 16

Tendons

Question 17

– sheet-like structures

Answer 17

Aponeuroses

Question 18

Sites of muscle attachment

Answer 18

Bones
Cartilages
Connective tissue coverings

Question 19

*Accessory Structures of Muscles

located in certain tendons or joint capsules specifically at friction points; derived from the Latin word “sesamum” (sesame seed), due to the small size of most sesamoids

Functions:
a. protect tendons especially those passing over bony prominences
b. provide greater surface area for attachment of tendons over certain joints
c. divert the pull of tendons so that greater force is applied to the part being moved

Answer 19

Sesamoid bones

Question 20

*Accessory Structures of Muscles

are connective tissue sacs filled with a viscous fluid and they reduce friction; they usually develop between tendons, ligament or muscle or between a bony growth and the skin

Answer 20

Bursae

Question 21

*Accessory Structures of Muscles

are double-layered sacs with synovial fluid or synovia; they wrap tendons as they pass bony or fibrous projections.

Answer 21

Synovial tendon sheaths
or “synovium”

Question 22

*Accessory Structures of Muscles

are the auxillary tissues that connect muscle to muscle.

Answer 22

Fasciae

Question 23

*Accessory Structures of Muscles

are connective tissues that connect one bone to another bone.

Answer 23

Ligaments

Question 24

*Accessory Structures of Muscles

are connective tissues that connect muscles to bones.

Answer 24

Aponeuroses and tendons

Question 25

 also called aponeurotica  an extremely delicate, thin sheath-like structure, which attaches muscles to the bones  white, transparent sheath, a flat structure  When a muscle moves by flexing or extending, an aponeurosis acts like a spring to bear the extra pressure and tension.

Answer 25

Aponeurosis

Question 26

 tough, rounded cord-like structure which are extensions of the muscle  white, shiny and glazed, rope- like tough structure  moves a bone when a muscle contracts. This allow the body to move and be flexible while aponeuroses allow the body to be strong and stable.

Answer 26

Tendon

Question 27

 Has no striations  Spindle-shaped cells  Single nucleus  Involuntary – no conscious control  Found mainly in the walls of hollow organs  Slow, sustained and tireless

Answer 27

Smooth Muscle

Question 28

 Has striations  Usually has a single nucleus  Joined to another muscle cell at an intercalated disc  Involuntary  Found only in the heart  Steady pace!

Answer 28

Cardiac Muscle

Question 29

Function of Muscles

Answer 29

 Produce movement  Maintain posture  Stabilize joints  Generate heatis attained due to a muscle moving an attached bone

Question 30

is attained due to a muscle moving an attached bone

Answer 30

Movement

Question 31

Muscles are attached to at least two points, which are

Answer 31

Origin and Insertion

Question 32

attachment to a moveable bone

Answer 32

origin

Question 33

Results of increased muscle use (4)

Answer 33

 Increase in muscle size  Increase in muscle strength  Increase in muscle efficiency  Muscle becomes more fatigue resistant

Question 34

*Naming of Skeletal Muscles Direction of muscle fibers

Answer 34

rectus (straight)

Question 35

*Naming of Skeletal Muscles Relative size of the muscle

Answer 35

maximus (largest)

Question 36

*Naming of Skeletal Muscles Location of the muscle

Answer 36

many muscles are named for bones (e.g., temporalis)

Question 37

*Naming of Skeletal Muscles Number of origins

Answer 37

triceps (three heads)

Question 38

*Naming of Skeletal Muscles Location of the muscles origin and insertion

Answer 38

sterno (on the sternum)

Question 39

*Naming of Skeletal Muscles Shape of the muscle

Answer 39

deltoid (triangular)

Question 40

*Naming of Skeletal Muscles Action of the muscle

Answer 40

flexor and extensor (flexes or extends a bone)

Question 41

These muscles cause the movement to occur by contracting. They are also referred to as prime movers since they are the muscles that are primarily responsible for generating the movement

Answer 41

agonists

Question 42

These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position.

Answer 42

antagonists

Question 43

These muscles perform, or assist in performing, the same set of joint motion as the agonists. These are sometimes referred to as neutralizers because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.

Answer 43

synergists

Question 44

These muscles provide the necessary support to assist in holding the rest of the body in place while the movement occurs. These are also sometimes called stabilizers.

Answer 44

fixators

Question 45

The biceps brachii flex the lower arm. The brachoradialis, in the forearm, and brachialis, located deep to the biceps in the upper arm, are both synergists that aid in this motion.

Answer 45

Prime Movers and Synergists:

Question 46

To extend the leg at the knee, a group of four muscles called the ______ in the anterior compartment of the thigh are activated (and would be called the ___ of leg extension at the knee). A set of ____ called the __ in the posterior compartment of the thigh are activated to slow or stop the movement.

Answer 46

quadriceps femoris agonists antagonists hamstring

Question 47

inherited, muscle enlarge due to increased fat and connective tissue, but fibers degenerate and atrophy

Answer 47

Muscular Dystrophy

Question 48

lacking a protein to maintain the sarcolemma

Answer 48

Duchenne MD

Question 49

progressive weakness due to a shortage of acetylcholine receptors

Answer 49

Myasthemia Gravis