Human A&p Chapter 10 Muscle

Front 1

What type of muscle?
❑ striated
❑ multinucleated

Back 1

skeletal muscle

Front 2

What type of muscle?
❑ striated
❑ single nucleus per cell

Back 2

cardiac muscle

Front 3

What type of muscle?
❑ striated
❑ voluntary control

Back 3

skeletal muscle

Front 4

What type of muscle?
❑ attached to bones, cartilage, or fascia

Back 4

skeletal muscle

Front 5

What type of muscle?
❑ striated
❑ involuntary control

Back 5

cardiac muscle

Front 6

What type of muscle?
❑ found only in the heart

Back 6

cardiac muscle

Front 7

What type of muscle?
❑ non-striated

Back 7

smooth muscle

Front 8

What type of muscle?
❑ found in the walls of blood vessels, the respiratory passages, and the hollow visceral organs other than the heart

Back 8

smooth muscle

Front 9

How are most skeletal muscles arranged in the body?

Back 9

in agonist/antagonist pairs

Front 10

List 4 functions of skeletal muscles.

Back 10

produce movement
maintain posture
stabilize and strengthen joints
generate heat (shivering)

Front 11

______________ – attachment of a skeletal muscle that remains relatively fixed during muscular contraction

Back 11

muscle origin

Front 12

_______________ – attachment of a skeletal muscle that moves during muscular contraction

Back 12

muscle insertion

Front 13

Skeletal muscle cells are called __________.

Back 13

muscle fibers (or myofibers)

Front 14

Each muscle fiber in a skeletal muscle is surrounded by a sheath of reticular connective tissue proper called ____________.

Back 14

endomysium

Front 15

Muscle fibers are grouped into units called _____________.

Back 15

fascicles

Front 16

Muscle fibers are bundled together to form a fascicle by a surrounding connective tissue sheath called ______________.

Back 16

perimysium

Front 17

Fascicles are bundled together to form a skeletal muscle by a surrounding connective tissue sheath called _______________.

Back 17

epimysium

Front 18

______________ - the plasma membrane of a skeletal muscle cell

Back 18

sarcolemma

Front 19

______________ - the cytoplasm of a skeletal muscle cell

Back 19

sarcoplasm

Front 20

A complex organelle found only in skeletal and cardiac muscle that is composed of bundles of myofilaments

Back 20

myofibril

Front 21

The thin and thick filaments in a muscle cell are known as ____________.

Back 21

myofilaments

Front 22

In muscle cells, the thick filaments are composed of ___________.

Back 22

myosin

Front 23

In muscle cells, the thin filaments are composed of ___________.

Back 23

actin

Front 24

What forms the "cross-bridges" between the thick filaments and thin filaments in muscle cells?

Back 24

the myosin heads

Front 25

A rope-like protein arranged head to tail down the length of each actin filament in a muscle cell.

Back 25

tropomyosin

Front 26

What is tropomyosin doing in a resting muscle cell?

Back 26

It covers the myosin-binding sites on the thin filaments.

Front 27

Give 3 terms for the synapse between a motor neuron and a skeletal muscle fiber.

Back 27

neuromuscular synapse
neuromuscular junction
motor end-plate

Front 28

What neurotransmitter is used in the neuromuscular junction?

Back 28

acetylcholine

Front 29

What enzyme in the post-synaptic membrane of the motor end-plate destroys the neurotransmitter released from the motor neuron?

Back 29

acetylcholine esterase

Front 30

After the skeletal muscle action potential, what triggers the muscle contraction?

Back 30

an increase in the cytosolic Ca2+ concentration

Front 31

What feature of a striated muscle cell carries the muscle cell action potential deep into the cell interior?

Back 31

T-tubules

Front 32

What is the sarcoplasmic reticulum?

Back 32

a network of membrane-bound tubes inside muscle cells (esp. striated muscle cells) filled with Ca2+

Front 33

What term describes the sequence of events connecting the muscle action potential to the muscle contraction?

Back 33

excitation-contraction coupling

Front 34

In striated muscle, the muscle action potential causes the release of Ca2+ from intracellular stores. Where is the Ca2+ stored?

Back 34

in the sarcoplasmic reticulum

Front 35

In striated muscle, the muscle action potential causes the release of Ca2+ from the sarcoplasmic reticulum. What happens next?

Back 35

The Ca2+ binds to troponin, which then pulls the tropomyosin out of the way so that myosin can grab hold of the thin filaments and pull.

Front 36

An increase in the cytosolic Ca2+ concentration triggers muscle cell contraction. What happens to the Ca2+ that causes the muscle cell to relax?

Back 36

The Ca2+ is pumped back into the sarcoplasmic reticulum (striated muscle) or outside the cell (smooth muscle).

Front 37

A Ca2+ pump is also called a __________.

Back 37

Ca2+ ATPase

Front 38

What is the latent period of a skeletal muscle twitch?

Back 38

the time between the end of the skeletal muscle action potential and the beginning of contraction

Front 39

Define motor unit.

Back 39

a single motor neuron and all the skeletal muscle fibers it innervates.

Front 40

In what order are motor units recruited?

Back 40

in order of increasing size

Front 41

Define motor neuron pool.

Back 41

all of the motor neurons that innervate a given skeletal muscle

Front 42

A skeletal muscle contraction for which the force applied by the muscle is not sufficient to move the load. Consequently, the muscle does not shorten.

Back 42

isometric contraction

Front 43

A skeletal muscle contraction for which the muscle tension remains relatively constant.

Back 43

isotonic contraction

Front 44

An isotonic contraction during which the contracting skeletal muscle shortens.

Back 44

concentric contraction

Front 45

An isotonic contraction during which the contracting skeletal muscle lengthens.

Back 45

eccentric contraction

Front 46

A muscle cell which is being stimulated to hold a contraction very quickly begins to run low on ATP. How will the muscle cell quickly replenish its ATP supply?

Back 46

by transferring a phosphate from creatine-phosphate to ADP

Front 47

1 molecule glucose is catabolized to 2 pyruvate molecules in a process referred to as _____________.

Back 47

anaerobic glycolysis

Front 48

Does glycolysis require oxygen?

Back 48

NO

Front 49

Where in the cell does glycolysis occur?

Back 49

in the cytosol

Front 50

In glycoltic muscle, what happens to the pyruvate formed in glycolysis?

Back 50

It is converted to lactic acid, which is then transported out of the cell.

Front 51

What energy substrate does glycolytic muscle primarily use?

Back 51

glucose

Front 52

In oxidative muscle, what happens to the pyruvate produced by glycolysis?

Back 52

It is oxidized in the mitochondria for energy.

Front 53

How are fatty acids metabolized for energy?

Back 53

by oxidation in the mitochondria

Front 54

____________- the amount of extra oxygen required by muscle tissue during recovery from vigorous exercise

Back 54

oxygen debt

Front 55

What is ATP used for in a muscle contraction?

Back 55

1. the myosin ATPase activity for myosin to pull on the thin filaments
2. the Ca2+ pump to pump the Ca2+ back into the sarcoplasmic reticulum (striated muscle) or back out of the cell (smooth muscle)
3. the Na+/K+ pump to return the plasma membrane back to the resting membrane potential

Front 56

Give 3 names for skeletal muscle fibers that primarily use oxidation for energy.

Back 56

slow oxidative (SO) fibers
type I fibers
red muscle fibers

Front 57

What muscle fibers are the least fatigue-resistant??

Back 57

fast glycolytic (FG) fibers (white muscle fibers)

Front 58

What muscle fibers are the most fatigue-resistant?

Back 58

slow oxidative fibers (red muscle fibers)

Front 59

What type of muscle fiber?
❑ low glycogen content
❑ high mitochondrial content
❑ high myoglobin content
❑ high capillary density

Back 59

slow oxidative fibers (red muscle fibers)

Front 60

What type of muscle fiber?
❑ high glycogen content
❑ low mitochondrial content
❑ low myoglobin content
❑ low capillary density

Back 60

fast glycolytic (FG) fibers (white muscle fibers)

Front 61

Give 3 names for skeletal muscle fibers that primarily use glycolysis for energy.

Back 61

fast glycolytic (FG) fibers
type IIb fibers
white muscle fibers

Front 62

What skeletal muscle fiber type is best for short bursts of intense activity?

Back 62

fast glycolytic (FG) fibers

Front 63

Give another term for cardiac muscle cells.

Back 63

cardiomyocytes

Front 64

Cardiac or smooth muscles cells specialized to produce
rhythmic action potentials

Back 64

pacemaker cells

Front 65

In cardiac muscle, an action potential originates from pacemaker cells and spreads throughout the muscle. How does the action potential spread from one cardiomyocyte to the next?

Back 65

through gap junctions

Front 66

What is the major difference in excitation-contraction coupling between skeletal and cardiac muscle?

Back 66

Ca2+-induced Ca2+ release occurs in cardiac muscle.

Front 67

Explain Ca2+-induced Ca2+ release that occurs in stimulated cardiomyocytes.

Back 67

There is a voltage-gated Ca2+ channel in the t-tubules of cardiomyocytes. An action potential traveling down the t-tubules opens the voltage-gated Ca2+ channels, allowing Ca2+ from outside the cell to come into the cell. This Ca2+ then binds to and opens a ligand-gated Ca2+ channel in the sarcoplasmic reticulum.

Front 68

Where does most of the Ca2+ for smooth muscle contraction come from?

Back 68

from outside the cell (i.e. from the interstitial fluid)

Front 69

What type of smooth muscle?
❑ Cells are coupled by numerous gap junctions.
❑ contains pacemaker cells
❑ degree of contraction can be modulated by autonomic stimulation

Back 69

single-unit smooth muscle

Front 70

What type of smooth muscle?
❑ cells contract independently
❑ extensively innervated
❑ innervation necessary to induce contraction

Back 70

multi-unit smooth muscle

Front 71

Autonomic nerve fibers release neurotransmitter onto smooth muscle cells from...

Back 71

varicosities (swellings) in the nerve axons

Front 72

When a smooth muscle cell is excited, Ca2+ enters the cell and binds to ___________.

Back 72

calmodulin

Front 73

How is tropomyosin moved off of the myosin-binding sites of actin in smooth muscle?

Back 73

In smooth muscle, tropomyosin is held in the way by a protein called caldesomon. Ca2+-calmodulin binds to caldesmon and pulls it off the tropomyosin.

Front 74

After tropomyosin moves out of the way, there is still one more step before the mysoin can begin pulling on the thin filaments in smooth muscle. What is this step?

Back 74

Myosin light-chain kinase (activated by Ca2+-calmodulin) must phosphorylate the regulatory myosin light chains.