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Flashcards in Exam 3 Deck (37):
1

what is the role of tropomyosin in skeletal muscle

tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules

2

most skeletal muscles contain

muscle fibers of the same type

3

which of the following would be recruited later in muscle stimulation when contractile strength increases

motor units with larger, less excitable neurons

4

myoglobin

stores oxygen in muscle cells

5

what structure in skeletal muscle cells functions in calcium represent

sarcoplasmic reticulum

6

what does excess postexercise oxygen consumption represent

the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used

7

creatine phosphate functions in the muscle cell by

storing energy that will be transferred to ADP to resynthesize ATP

8

what is the primary function of wave summation

prevent muscle fatigue

9

which of the following surrounds the individual muscle cell

endomysium

10

rigor mortis occurs because

no ATP is available to release attached actin and myosin molecules

11

what is the functional unit of a skeletal muscle called

myofibril

12

what is the functional role of the T tubule

enhance cellular communication during muscle contraction

13

as a result the pyruvic acid is converted to

lactic acid

14

the mechanism of contraction in smooth muscle is different from skeletal muscle in that

the trigger for contraction is a rise in intracellular calcium

15

which of the following describes the cells of unitary smooth muscle

they consist of muscle fibers that are structurally independent of each other

16

an aerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is

glycolysis

17

muscle tone is __

a state of sustained partial contraction

18

the sliding filament model of contraction involves

actin and myosin sliding past each other and partially overlapping

19

after nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction

acetylcholinesterase destroying the ACh

20

what is the most distinguishing characteristic of muscle tissue

the ability to transform chemical energy into mechanical energy to move the body

21

hypothetically if a muscle were stretched to the point where thick and thin filaments no longer overlapped

ATP consumption would increase because the sarcomere is trying to contract

22

of the following items listed below, which is the best description for why skeletal muscle stores glycogen

skeletal muscle is a heavy consumer of energy

23

approximately 80% of a muscles fibers volume are the myofibrils. this characteristic reflects muscles ability to

produce relatively high amounts of ATP

24

when a sarcomere contracts and thin filaments move over thick filaments you would expect to see

the I bands to appear smaller

25

which type of lever is demonstrated by using scissors

first class lever

26

what type of lever system is described as LEF

third class lever

27

if a lever operates at a mechanical disadvantage it means that the

load is far from the fulcrum and the effort is applied near the fulcrum

28

which of these is not a way of classifying muscles

the type of muscle fibers

29

when the term biceps, triceps or quadriceps forms part of a muscles name, what does it tell you about the muscle

the muscle has two, three or four origins

30

the supraspinatus is named for its location on the posterior aspect of the scapula above the spine

to initiate abduction of the arm, to stabilize the shoulder joint and to help prevent downward dislocation of the humerous

31

which group of muscles elevates the first two ribs flexes and rotates the neck

the splenius

32

which of the following muscles is involved in crossing one leg over the other to produce the cross-legged position

the satorius

33

which of the following muscles fixes and depresses the ribs and stabilizes the pelvis during walking

rectus abdominous

34

a nursing infant develops a powerful sucking muscle that adults also use for whistling. what is this muscle called

buccinator

35

the sternocleidomastoid muscle inserts on the

sternum

36

the __ is the main chewing muscle

lateral pterygoid

37

the quads femoris is composed of three vastus muscles and the

semimembranosus