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Flashcards in Muscular System Deck (133)
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1

myology

scientific study of muscles

2

skeletal muscle

attached primarily to bone, striated and voluntary

3

cardiac muscle

most of the heart, striated and involuntary

4

smooth muscle

walls of hollow internal organs, blood vessels, stomach, non-striated, involuntary

5

functions of muscle tissue

1. produce body movements 2. stabilize body positions 3. store and move substances within the body 4. generate heat

6

tendon

""pick up sticks"" (panty hose) fascia, stretched beyond muscle as connective tissue attaches muscle to bone

7

muscle fascicle

groups of 10 to 100 or more muscle fibers, arranged in bundles

8

muscle fiber (cell)

1 ""pick up stick"" each muscle is a separate organ composed of hundreds of long, cylindrical cells, lie parallel to one another. contains myofibrils

9

myofibrils

""piece"" threads in sarcoplasm, extends lengthwise. contain the myofilaments

10

myofilaments

what thick and thin filaments are called, contractile proteins

11

thick filament- myosin

2 golf clubs twisted together, produce power stroke

12

thin filament- actin

twisted helix, binding site for myosin

13

thin filament- tropomyosin

covers the myosin head-binding site on actin in relaxed muscle

14

thin filament- troponin

once bound to calcium, drags tropomyosin away from the binding sites

15

sarcomere

describes the arrangement of the above myofilaments. compartments where think and thick filaments are arranged. basic functional unit of the muscle cell

16

sarcoplasm

muscle fiber cytoplasm

17

the sliding filament mechanism

describes a muscle contraction. the length of the filaments do not change, filaments overlap, shortening the sarcomere as the muscle contracts.

18

sarcoplasmic reticulum

a fluid filled cavity around each myofibril that stores calcium via the calcium pump

19

calcium

in relaxed muscle, calcium is stored in the sarcoplasmic reticulum. when released starts the filaments sliding (contracts)

20

what must happen for a muscle to contract?

motor neuron, action potential, acetylcholin is released, release of calcium, calcium released from sarcoplasmic reticulum, calcium binds to troponin

21

ATP

energy source that makes all this happen

22

how does muscle fiber relax?

action potential stops, acetylcholine stops, calcium chambers close, calcium pump removes the remaining calcium, myosin heads no longer can bind, muscle will now relax

23

origin of muscle

attachment to tendon to stationary bone

24

insertion of muscle

attachment of other tendon to movable bone

25

belly of muscle

fleshy portion of muscle between the tendons

26

muscles of facial expression

originate in the bones of skull and insert into the skin

27

frontal belly

scalp anteriorly

28

occipital belly

scalp posteriorly

29

orbicularis oris

closes and protrudes the lips. shapes the lips during speech

30

zygomaticus (major and minor)

muscles for smiling