musclar system [contractions] - unit 3

Question 1

how many muscles in human body?

Answer 1

600+

Question 2

muscles are made of

Answer 2

skeletal muscle cells/fivers. they are the biggest in the body.

Question 3

4 CT coverings associated with muscles

Answer 3

endomysium, perimysium, epimysium, and deep facia

Question 4

type of CT covering. areolar CT covering individual skeletal muscle cells which bind neighboring cells.

Answer 4

endomysium

Question 5

type of CT covering. dense irregular CT that packages bundles of Skeletal muscle cells into “fascicles”

Answer 5

perimysium

Question 6

type of CT covering. dense irregular CT that covers the entire skeletal muscle

Answer 6

epimysium

Question 7

type of CT covering. dense irregular CT that packages/surround multiple cells.

Answer 7

deep facia

Question 8

Dense irregular CT cord that connects skeletal muscle cells to bone

Answer 8

tendons

Question 9

tendon term. bone that skeletal muscle is bounded to/anchored to.

Answer 9

origin

Question 10

tendon term. bone that moves when the muscle contracts

Answer 10

insertion

Question 11

type of CT covering. body movement that muscle provides when it contracts.

Answer 11

action

Question 12

skeletal muscle cell structure. plasma membrane.

Answer 12

sarcolemma

Question 13

skeletal muscle cell structure. stores Ca2+ and releases it into myofibrils upon electrical stimulation. its surrounds myofibrils.

Answer 13

sarcoplasmic reticulum

Question 14

skeletal muscle cell structure. cytoplasm.

Answer 14

sacroplasm

Question 15

skeletal muscle cell structure. pits/invaginations of sarcolemma that extend deep into the cell to SR. they conduct/transmit electricity from sarcolemma to SR.

Answer 15

Transverse Tubules (T-Tubles)

Question 16

skeletal muscle cell structure. part of cytoskeleton. cylindrical structures that spam length of cell which contain contractile protein machinery of cell. give cell its striated appearance.

Answer 16

myofibrils

Question 17

Myofibril structure: zig-zag shaped proteins that anchor thin filaments

Answer 17

z-discs

Question 18

Myofibril structure: made of striated-like proteins called “actin” twisted together. myosin heads of myosin proteins bind and pull on them. (generates contraction force)

Answer 18

thin filaments

Question 19

Myofibril structure: covers thin filaments and blocks myosin heads from binding. it binds to Ca2+ released from SR and folds over to expose thin filaments. (triggers contraction force)

Answer 19

troponin-Tropomyosin Complex

Question 20

Myofibril structure: bundles of myosin that bind to ATP and break it down to recharge heads.

Answer 20

Thick Filaments

Question 21

contraction step __. electricity transmitted from T-Tubles to SR stimulate Ca2+ release into neighboring myofibrils. Troponin-Tropomysoin bind Ca2+ and fold over to expose thin filaments to thick filaments. Myosin heads with ADP bind to it.

Answer 21

1

Question 22

contraction step __. myosin heads release ADP, bends/twists neck to generate contraction force.

Answer 22

2

Question 23

contraction step ___. myosin heads bind ATP to detach/release from thin filaments.

Answer 23

3

Question 24

contraction step ___. myosin heads break down ATP into ADP+P and use energy released to recharge+recock heads.

Answer 24

4

Question 25

(for contractions) if electricity ____ to stimulate cell/SR then Ca2+ release will continue converting into myofibrils. Troponin-Tropomyosin continues to bind Ca2+

Answer 25

continues

Question 26

(for contractions) if electricity ___ then SR pumps Ca2+ into itself and diffuse it out of myofibril. Troponin-Tropomyosin releases Ca2+ and block thin filaments.