Muscle Structure/Function

Question 1

Delicate areolar connective tissue surrounding each muscle fiber

Answer 1

Endomysium

Question 2

Collagenic membrane wrapping several muscle fibers together to form a fascicle

Answer 2

Perimysium

Question 3

Dense connective tissue that binds together a large number of fascicles (sheathes the entire muscle)

Answer 3

Epimysium

Question 4

Cordlike, dense fibrous connective tissue that connects muscle fascia to periosteum of the bone

Answer 4

Tendon

Question 5

Sheet like dense connective tissue tendons that take the form of broad, thin sheets of dense connective tissue and may attach muscle to other muscles

Answer 5

Aponeurosis

Question 6

Less movable end (generally proximal)

Answer 6

Origin

Question 7

The more movable end (generally distal)

Answer 7

Insertion

Question 8

Light bands with dense, fibrous Z line/disc in the middle

Answer 8

I bands

Question 9

The area from Z line to Z line

Answer 9

Sarcomere

Question 10

Myofibrils are made up of even smaller threadlike structures called

Answer 10

Myofilaments

Question 11

What two contractile proteins are myofilaments made of

Answer 11

Actin and myosin

Question 12

Thin filaments in I band and A band that attach to the Z lines

Answer 12

Actin

Question 13

What is actin made of

Answer 13

Actin, tropomyosin, troponin

Question 14

Thick filaments in A band

Answer 14

Myosin

Question 15

H zone has only _________ filaments

Answer 15

Thick

Question 16

The M line is formed by

Answer 16

Linkages between the thick filaments that hold them in parallel

Question 17

Contractile unit of muscle

Answer 17

Sarcomere

Question 18

Each thick filament is surrounded by

Answer 18

Six thin filaments

Question 19

Each thin filaments is enclosed by

Answer 19

Three thick filaments

Question 20

Plasma membrane of the muscle cell

Answer 20

Sarcolemma

Question 21

Where the A band meets the I band, the sarcolemma indents into the muscle cell, forming a

Answer 21

A transverse tubule

Question 22

These indent into the terminal cisternae of the smooth endoplasmic reticulum

Answer 22

T tubules

Question 23

The junction between a nerve fiber and a muscle cell

Answer 23

Neuromuscular junction

Question 24

A neuron and all the muscle cell it stimulates

Answer 24

Motor unit

Question 25

Each nerve fiber breaks up into many branches called

Answer 25

axon terminals

Question 26

The small fluid filled gap that separates the neuron and muscle fiber membranes

Answer 26

Synaptic cleft

Question 27

Muscles responsible for producing a particular movement

Answer 27

Prime movers (agonists)

Question 28

Muscles that oppose or reverse a movement

Answer 28

Antagonists

Question 29

When a prime mover is active, the fibers of the antagonists are

Answer 29

Stretched and in a relaxed state

Question 30

Does the action of agonists by reducing undesirable or unnecessary movement

Answer 30

Synergists

Question 31

Stabilize movement across joints

Answer 31

Synergists

Question 32

Specialized synergists that immobilize the origin of a prime mover so that all of the tension is extorted at the insertion

Answer 32

Fixators

Question 33

Muscles with fibers running parallel to the midline if the body will have the term

Answer 33

Rectus

Question 34

Muscles with fibers that run at right angles and obliquely will be termed

Answer 34

Transverse and oblique

Question 35

Force generation of type 1 skeletal muscle fibers

Answer 35

Small, slow oxidative

Question 36

Force generation of type 2 skeletal muscle fibers

Answer 36

Medium, fast oxidative

Question 37

Force generation of type 3 skeletal muscle fibers

Answer 37

Large, fast glycolic

Question 38

The speed of contraction is determined by

Answer 38

The speed in which ATPases split ATP

Question 39

Use aerobic pathways

Answer 39

Oxidative fibers

Question 40

What are the two types of muscle fibers

Answer 40

Slow and fast

Question 41

Use anaerobic glycolysis

Answer 41

Glycolytic fibers

Question 42

These contract slowly, have slow acting myosin ATPases and are fatigue resistant

Answer 42

Slow oxidative fibers

Question 43

These contract quickly, have fast myosin ATPases and have moderate resistance to fatigue

Answer 43

Fast oxidative fibers

Question 44

These contract quickly, have fast myosin ATPases and are easily fatigued

Answer 44

Fast glycolic fibers

Question 45

The outside extracellular face is positive, while the inside face is

Answer 45

Negative- this difference in charge is the resting membrane potential

Question 46

Sodium potassium pump

Answer 46

3 sodium out, 2 potassium in

Question 47

Resting membrane is normally 50-100 times more permeable to ____ as to sodium

Answer 47

Potassium

Question 48

Inside the nerve fiber are more ______ that can’t diffuse out

Answer 48

Anions

Question 49

Abrupt, pulse like changes in the membrane potential

Answer 49

Action potential

Question 50

What is a normal negative

Answer 50

-85mV

Question 51

What is an instantaneous positive

Answer 51

45mV

Question 52

The sudden loss of normal negative potential in the fiber

Answer 52

Membrane depolarization

Question 53

The positive potential that develops momentarily in membrane depolarization is called

Answer 53

Reverse potential

Question 54

The excess positive charges inside the fiber are transferred back out of the fiber and the normal negative resting membrane potential returns

Answer 54

Membrane repolarization

Question 55

Brief hyperpolarization period (more negative than RMP) following the action potential

Answer 55

After potential

Question 56

The period of time of completely insensitivity to another stimulus

Answer 56

Absolute refractory period

Question 57

The period near the end of the repolarization phase where a greater than threshold strength stimulus can initiate another action potential

Answer 57

Relative refractory period

Question 58

The response of a muscle to a single, brief, threshold stimulus

Answer 58

Muscle twitch

Question 59

A condition in which skeletal muscle contracts more forcefully in response to the same strength of stimulus after it has contracted several times

Answer 59

Treppe