Chapter 9/ Muscle Physiology

Question 1

Skeletal
cardiac
smooth

Answer 1

muscle tissue

Question 2

Has myofibrils and sarcomeres

Answer 2

skeletal muscle

Question 3

Has special structures called transverse tubules

Answer 3

skeletal muscle

Question 4

-Contain many mitochondria
-Multinucleated

Answer 4

skeletal muscle cell

Question 5

Sarcolemma

Answer 5

Plasma membrane

Question 6

Sarcoplasm

Answer 6

Cytoplasm

Question 7

Sarcoplasmic reticulum

Answer 7

Smooth ER

Question 8

-Transverse tubules
-sarcoplasmic reticulum
-myofibrils
-cytosol
-plasma membrane
-mitocondria
-terminal cisternae
-opening of transverse tubule to extracellular fluid

Answer 8

structure of a muscle fiber

Question 9

Give skeletal
muscle striated
appearance
(skeletal muscle )

Answer 9

Myofibrils

Question 10

Orderly
arrangement of
thick and thin
filaments
(skeletal muscle)

Answer 10

myofibrils-

Question 11

Composed almost entirely of myosin proteins

Answer 11

Thick filamant

Question 12

Two large polypeptide chains

Answer 12

Myosin

Question 13

Two globular heads and two intertwined tails

Answer 13

Myosin

Question 14

-Globular heads extend out, form cross bridges
– Globular heads contain binding sites for actin and
ATP

Answer 14

Myosin

Question 15

Primarily composed of actin
(Also, troponin and tropomyosin)

Answer 15

thin filament

Question 16

-Each G actin subunit has a binding site for myosin
-Form polymers of two intertwined, helical chains.
(thin filament)

Answer 16

actin

Question 17

– Regulatory protein
– Overlaps binding sites on actin for myosin, inhibits
interaction when muscle fiber is relaxed
(thin filament)

Answer 17

tropomyosin

Question 18

– Regulatory protein
– Forms complex with actin and tropomyosin
(thin filament)

Answer 18

troponin

Question 19

– Reversibly binds Ca2+
– When Ca2+ is bound troponin changes
conformation to pull tropomyosin away from the myosin binding sites
(thin filament)

Answer 19

troponin

Question 20

spring-like protein, prevents overstretching

Answer 20

Titin

Question 21

Homologous to endoplasmic reticulum

Answer 21

sarcoplasmic reticulum

Question 22

Stores and releases Ca2+ following membrane
excitation

Answer 22

sarcoplasmic reticulum

Question 23

deep invaginations of the
sarcolemma

Answer 23

T-tubules

Question 24

Connected to sarcoplasmic reticulum

Answer 24

T-tubules

Question 25

One motor neuron +
all skeletal muscle
fibers it innervates

Answer 25

motor units

Question 26

Muscle fibers are
innervated by only
one

Answer 26

motor neuron

Question 27

Many motor units
within a whole

Answer 27

muscle organ

Question 28

Skeletal muscle is under voluntary/unvoluntary control

Answer 28

voluntary

Question 29

Stimulation by motor neurons is the only
mechanism by which action potentials are
initiated in

Answer 29

skeletal muscle

Question 30

Axons of motor neurons are myelinated and
are BLANK -diameter axons in the body

Answer 30

diameter

Question 31

Propagate action potentials at BLANK velocity

Answer 31

high

Question 32

The axon terminal of a motor neurons release (ACH)

Answer 32

acetylcholine