Taylor Summation

Question 1

what controls intensity of skeletal muscle contraction

Answer 1

summation

Question 2

type of summation that increases force of contraction by increasing frequency of action potentials

Answer 2

temporal summation

Question 3

type of summation that increases intensity of contraction by increasing the amount of motor units

Answer 3

spatial summation

Question 4

what are being summated during temporal summation

Answer 4

muscle twitches, NOT action potentials

Question 5

smallest motor unit

Answer 5

small neurons innervating few type I muscle fibers

Question 6

largest motor unit

Answer 6

large neurons innervating many type II muscle fibers

Question 7

what increases when the load to be moved increases

Answer 7

firing frequency

Question 8

how are additional motor units recruited

Answer 8

small to large

Question 9

assessment of muscle activity through electrodes inserted into muscle

Answer 9

electromyography

Question 10

what exactly does electromyography measure during contraction

Answer 10

motor unit action potentials (MUAPs)

Question 11

low frequency and high amplitude indicative of what

Answer 11

neuropathy

Question 12

low amplitude and short duration are sometimes indicative of what

Answer 12

myopathies

Question 13

transient involuntary contractions; electrically active

Answer 13

cramps

Question 14

failure to relax; electrically silent

Answer 14

contracture

Question 15

why does myopathy show low amplitude and short duration

Answer 15

b/c some fibers are not participating

Question 16

contracting at constant length (no shortening)

Answer 16

isometric contraction

Question 17

increase muscle length increases what

Answer 17

forceand velocity

Question 18

maximal force is achieved when

Answer 18

at optimal length

Question 19

contraction at constant force (muscle shortens)

Answer 19

isotonic contraction

Question 20

during isotonic contraction, what do you see initially before muscle shortens

Answer 20

isometric contraction

Question 21

maximum force is seen at what muscle length

Answer 21

optimal (Lo)

Question 22

increasing the load on the muscle does what to the velocity of shortening

Answer 22

decreases

Question 23

decreasing initial length of muscle does what to velocity of shortening;increase length=

Answer 23

decreasing; increase length=increasing velocity

Question 24

_____ is independent of initial length

Answer 24

Vmax

Question 25

contracting while shortening (arm curl)

Answer 25

concentric contraction

Question 26

contracting while lengthening (negative arm curl)

Answer 26

eccentric contraction

Question 27

contraction most susceptible to injury

Answer 27

eccentric contraction

Question 28

neural circuit at the level of the spinal cord providing automatic link between sensory input and a specific motor output (alpha motor neurons)

Answer 28

reflex arc

Question 29

detects length and deals with stretch and speed of stretch; protects muscle from overstretch and has normal reflex arc

Answer 29

muscle spindle

Question 30

not in muscle but in tendon; responds to contraction, make sure muscle doesn’t overcontract and deals with relaxation

Answer 30

golgi tendon organ

Question 31

“knee jerk reflex”; stretches quad and stretch muscle spindle and causes normal reflex

Answer 31

myotatic reflex

Question 32

0 (no response and deals with Westphal’s sign)

Answer 32

hypoactive

Question 33

4+ and deals with clonus

Answer 33

hyperactive

Question 34

often indicates neuropathy (upper motor neuron lesion)

Answer 34

clonus

Question 35

these fibers are used during strenuous exercise

Answer 35

type I and II

Question 36

these fibers are used during endurance and requires oxygen

Answer 36

type I

Question 37

during a marathon, type I fibers are being used but what happens when glycogen stores and glucose have been depleted and person is just dependent on FA’s after this said event

Answer 37

“the wall”

Question 38

the inability of muscle to maintain force

Answer 38

fatigue

Question 39

during high intensity exercise, what stops muscle from contracting (fatigue)

Answer 39

low pH

Question 40

temporary involuntary muscle contraction (spasms)

Answer 40

cramps

Question 41

quick involuntary muscle twitches (random spasm)

Answer 41

fasciculations

Question 42

broad involuntary muscle jerk

Answer 42

myoclonus

Question 43

extended contraction due to inability of muscle to relax

Answer 43

contracture