Muscle

Question 1

______ muscle cells are multinucleated.

Answer 1

Skeletal

Question 2

Muscles are composed of _____.

Answer 2

muscle fasciculi

Question 3

Muscle fasciculi are made up of _____.

Answer 3

muscle fibers

Question 4

Muscle fibers are made of ______.

Answer 4

myofibrils

Question 5

What surrounds muscles?

Answer 5

Epimysium

Question 6

What contains muscle fibers?

Answer 6

Perimysium

Question 7

What separates muscle fibers?

Answer 7

Endomysium

Question 8

During embryonic development, myoblasts fuse to become ______.

Answer 8

myotubes

Question 9

Three smooth muscle cells come from ectoderm. What are they?

Answer 9

Pupillary, mammary, and sweat glands.

Question 10

Actin filaments connect to the ____, a part of the I band.

Answer 10

Z line

Question 11

The myosin thick filaments occupy the _____ section of the _____.

Answer 11

H band; A band

Question 12

The ____ line is in the middle of the A band; it is where myosin attaches.

Answer 12

M

Question 13

A myofibril is _____.

Answer 13

lots of sarcomeres placed end-to-end

Question 14

A sarcomere is defined as the molecular area from _____.

Answer 14

one Z disc to the next Z disc

Question 15

To stabilize the actin filaments, ____ proteins bind to the positive ends (at the ____ line).

Answer 15

CapZ; Z

Question 16

At the negative end of the actin filaments, ___ proteins bind to stabilize the polymers.

Answer 16

tropomodulin

Question 17

The nuclei of skeletal muscle cells are located on the _____ of the cells.

Answer 17

peripheries

Question 18

The gap junctions of cardiac muscle cells are located in the ____.

Answer 18

intercalated discs

Question 19

In smooth muscle, calcium binds to ____, instead of troponin. That complex then activates ____.

Answer 19

calmodulin; myosin light chain kinase

Question 20

What is a myofilament, and how does it differ from myofibrils?

Answer 20

Myofilaments are the polymers of muscle action (actin, myosin, tropomyosin, and troponin), while myofibrils are collections of sarcomeres.

Question 21

Titin connects _____.

Answer 21

myosin to the Z line

Question 22

Nebulin connects ______.

Answer 22

actin to the Z line

Question 23

_____ cross-links actin filaments.

Answer 23

Alpha-actinin

Question 24

Triads allow the connection of ___ and ___.

Answer 24

transverse tubules; sarcoplasmic reticulum

Question 25

A ______ is a group of muscle fibers innervated by a single neuron.

Answer 25

motor unit

Question 26

_______ is the state in which calcium is being released constantly and muscles contract constantly.

Answer 26

Tetanus

Question 27

The positive ends of actin are connected to the _____.

Answer 27

Z disc

Question 28

Each myosin head contracts __ times per second in slow twitch muscles and ___ times per second in fast twitch muscles.

Answer 28

5; 20

Question 29

In cardiac muscle, ____ is needed (from DHPR activation) to induce calcium release from the sarcoplasmic reticulum.

Answer 29

calcium (without extracellular Ca, the heart will not contract)

Question 30

As a result of exercise, each ______ gets larger in diameter.

Answer 30

muscle fiber

Question 31

_______ induces proliferation of satellite cells, a group of cells that repair skeletal muscle.

Answer 31

Leukemia Inhibitory Factor (LIF)

Question 32

________ connects actin to the cell membrane.

Answer 32

Dystrophin