CHAPTER 6: Contraction of Skeletal Muscle

Question 1

How many % of the
body is skeletal muscle?

Answer 1

40%

Question 2

How many % of the
body is smooth and cardiac muscle?

Answer 2

10%

Question 3

all skeletal muscles are composed of
numerous fibers ranging from what size?

Answer 3

10 to 80 micrometers in diameter

Question 4

In most skeletal muscles, each fiber extends the entire length of the muscle. Except for about ______% of the fibers, each fiber is usually innervated by only one nerve
ending.

Answer 4

2%

Question 5

a thin membrane enclosing a Skeletal Muscle Fiber

Answer 5

Sarcolemma

Question 6

The sarcolemma consists of a
true cell membrane, called what?

Answer 6

plasma membrane

Question 7

Myofibrils are composed of what?

Answer 7

Actin and Myosin Filaments

Question 8

Each muscle fiber contains several hundred
to several thousand of what?

Answer 8

myofibrils

Question 9

Each myofibrils is composed of how many myosin and actin?

Answer 9

1500 adjacent myosin filaments
3000 actin filaments

Question 10

large polymerized protein molecules that are responsible for the actual muscle contraction

Answer 10

actin and myosin