Chapter 10 Muscle Tissues Notes

Question 1

6 functions of skeletal muscle

Answer 1

produce skeletal movement
maintain position
support soft tissues
guard openings
maintain temp
store nutrients

Question 2

dense layer of connective tissue that surrounds entire skeletal muscle

Answer 2

epimysium

Question 3

delicate connective tissue that surrounds skeletal muscle fibers and ties adjacent muscle fibers together

Answer 3

endomysium

Question 4

bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone

Answer 4

tendon

Question 5

advantage of having many nuclei in a skeletal muscle fiber

Answer 5

large amount of proteins can quickly grow/repair

Question 6

skeletal muscle fibers are formed by embryonic cells called

Answer 6

myoblasts

Question 7

repeating unit of a skeletal muscle fiber

Answer 7

sarcomeres

Question 8

interactions between actin and myosin filaments of the sarcomere are responsible for

Answer 8

contractions

Question 9

cross-bridges are portions of

Answer 9

actin filaments

Question 10

active sites are blocked by

Answer 10

tropomyosin

Question 11

narrow space between synaptic terminal and muscle fiber

Answer 11

synaptic cleft

Question 12

active sites on the actin become available for binding after

Answer 12

calcium bonds to receptor

Question 13

two protein molecules connected by myosin cross-bridges during muscle contraction

Answer 13

myosin

actin

Question 14

rapid rise and fall in force produced by a muscle fiber after a single action potential

Answer 14

twitch

Question 15

contraction in which muscle fibers do not shorten

Answer 15

isometric contraction

Question 16

at peak levels of muscle exertion the mitochondria can supply

Answer 16

1/3 of ATP needed

Question 17

after heavy exercise, of energy reserves in a muscle are depleted, this occurs

Answer 17

oxygen debt

Question 18

type of muscle fiber that is most resistant to fatigue

Answer 18

slow fiber

Question 19

muscular force can be adjusted to match different loads by

Answer 19

• more/larger motor units

- increase frequency/action potential

Question 20

the cytoplasm of neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter

Answer 20

ACH

Question 21

aerobic metabolism provides _____ percent of the ATP demands of a resting muscle cell

Answer 21

95%

Question 22

large diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of

Answer 22

fast fibers

Question 23

when hormone directly stimulates growth of muscle tissue, leading to increased muscle mass

Answer 23

testosterone

Question 24

because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have the following adaptations:

Answer 24

blood vessels

mitochondria

Question 25

after death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm

Answer 25

rigor mortis

Question 26

large motors are found in ______ muscles, and small motors are found in ______ muscles

Answer 26

larger

smaller

Question 27

what would happen if blood flow decrease to a muscle

Answer 27

lack oxygen
shift to glycosis
fatigue
pyruvic acid to lactic acid

Question 28

__ myosin head binds ATP molecule and detaches from actin
__ free myosin head splits ATP
__ calcium ion is releases from sarcoplasmic reticulum
__ myosin cross-bridges bind to actin
__ myosin head pivots toward center of sarcomere
__ calcium ion binds to troponin

Answer 28

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