muscular system [contractions pt 2] - unit 4

Question 1

two types of contractions

Answer 1

isometric and isotonic contraction.

Question 2

type of contraction. when a muscle contracts it generates force but doesn’t change in length. the myosin heads are pulling on the thin filaments

Answer 2

isometric contraction

Question 3

type of contraction. muscle contracts + generates force and changes in length.

Answer 3

isotonic contraction

Question 4

two types of isotonic contractions

Answer 4

concentric and eccentric contraction

Question 5

type of isotonic contraction. muscle shortens during contraction. the myosin heads pull and move the thin filaments. (z-discs are pulled together)

Answer 5

concentric contraction

Question 6

type of isotonic contraction. muscle lengthens during contraction. the myosin heads pull on thin filaments while the filaments go in an opposite direction.

Answer 6

eccentric contraction

Question 7

name for a motor neuron (several hundred per skeletal muscle)

Answer 7

motor unit

Question 8

muscles with ____ motor units have a setup for more precise movements

Answer 8

more

Question 9

muslces with ___ motor units have a setup for imprecise movements

Answer 9

less

Question 10

quick weak skeletal muscle contractions that arise from a single electrical stimulant to a skeletal muscle or motor unit.

Answer 10

muscle twitch

Question 11

increase contraction strength due to an increased frequency of electrical stimulation to a skeletal muscle. (tetanic contraction / tetanus)

Answer 11

wave summation

Question 12

two types of wave summation

Answer 12

unfused and fused tetanus

Question 13

type of wave summation. moderate frequency of stimulation. there are brief periods of partial relaxation prior to subsequent electrical stimulation (erratic twitches)

Answer 13

unfused tetanus

Question 14

type of wave summation. high frequency of stimulation. contractions increase in contraction force. (continuous release of Ca2+ from SR into myofibrils) (big flexion)

Answer 14

fused tetanus

Question 15

an increase of contraction force due to the number of motor units recruited to a skeletal muscle. (NOTE: inc of motor units = inc of contraction force)

Answer 15

spatial summation

Question 16

how skeletal muscles generate ATP

Answer 16

muscle metabolism

Question 17

chemical that sustains muscle contractions

Answer 17

ATP

Question 18

myosin heads bind to ATP and release from thin filaments then breakdown to ADP+P and use energy to recharge the heads in order to ____

Answer 18

sustain muscle contractions

Question 19

typical skeletal muscle cells only have enough stored ATP to sustain about ___ seconds of continuous contraction

Answer 19

six

Question 20

the first metabolic system. it regenerates ATP to sustain contraction/exercise.

Answer 20

creatine phosphate system

Question 21

a small protein molecule with a phosphate attached and reacts with ADP to form new ATP

Answer 21

creatine phosphate

Question 22

typical skeletal muscle cells have enough creatine phosphate stored to generate about ___ seconds worth of ATP for sustained contraction/exercise.

Answer 22

ten

Question 23

metabolic process that regenerates ATP via glucose breakdown and produces pyruvic acid

Answer 23

glycolysis

Question 24

a process of 10 reactions into smaller carbs

Answer 24

glucose breakdown

Question 25

(glycolysis) pyruvic acid without O2. diffuses out of cell enters bloodstream, taken by liver cells, converted to glucose glucose.

Answer 25

lactic acid

Question 26

(glycolysis) pyruvic acid with O2. in mitochondria, breakdown material to generate ATP

Answer 26

aerobic respiration

Question 27

skeletal muscle is unable to sustain maximal contraction strength

Answer 27

muscle fatigue

Question 28

4 causes of muscle fatigue

Answer 28

Lack of ATP, lactic acid buildup, phosphate buildup, ionic imbalances

Question 29

cause of muscle fatigue. required for myosin heads to detach from thin filaments and recharge.

Answer 29

lack of ATP

Question 30

cause of muscle fatigue. lactic acid diffuses into myofibrils and interferes with myosin heads binding to thin filaments

Answer 30

lactic acid buildup

Question 31

cause of muscle fatigue. when ATP is broken down into ADP+P. P interferes with Ca2+ channels in SR and blocks Ca2+ release

Answer 31

phosphate buildup

Question 32

cause of muscle fatigue. concentration of Na+ and K+ ions go out of whack in body and skeletal muscle cells when excessive sweating.

Answer 32

ionic imbalances

Question 33

skeletal muscle types

Answer 33

slow oxidative cells/fibers, fast glycolytic cells/fibers, fast oxidative glycolytic cells/fibers

Question 34

type of skeletal muscle. have myosin that breaks down ATP slowly, most efficient at generating ATP via aerobic respiration. has high levels of mitochondria/myoglobin. “Slow” twitch fibers.

Answer 34

slow oxidative cells/fibers

Question 35

type of skeletal muscle. has myosin that breaks down ATP quickly, generates ATP efficiently via glycolysis, has low levels of mitochondria/myoglobin. “Fast twitch fibers”

Answer 35

fast glycolytic cells/fibers

Question 36

type of skeletal muscle. moderate levels of mitochondria/myoglobin, efficient at glycolysis and aerobic respiration. “Moderate twitch”

Answer 36

fast oxidative glycolytic cells/fibers

Question 37

steroids that stimulate muscle cells to generate more myofibrils

Answer 37

anabolic steroids

Question 38

proportion of each skeletal muscle cell type in a given muscle is determined

Answer 38

genetically/via exercise

Question 39

two types of exercise training

Answer 39

endurance, weight

Question 40

type of training. stimulates cells to increase production of myoglobin/mitochondria. cells become more efficient at aerobic respiration. converts FG to FOG cells

Answer 40

endurance training

Question 41

type of training. microscopic tears in muscle cells then they repair+stimulate to generate more contractile proteins/myofibrils. convets FOG to FG cells

Answer 41

weight training