lecture graphs

motor unit recruitment (stimulus intensity)

Name this graph

length tension curve

Name this graph

Muscle twitch

treppe

name this graph

tetanus

name this graph

wave summation

name this graph

treppe

.. also known as the staircase effect

treppe

which graph does each stimulus produce a separate twitch, with full relaxation between twitches?

treppe

in this graph the force of each successive twitch gradually increases

if enough sodium channels open the muscle will contract

what is the all or none law for skeletal muscle contraction?

motor unit recruitment (stimulus intensity)

in which graph does stimulus intensity increase causing the muscle force to increase

increases

as stimulus intensity increases, muscle force … ? in a motor unit recruitment (stimulus intensity) graph

motor neuron

a motor unit consists of one ? and all the muscle fibers it controls

increases

when more motor units are activated, the total muscle force… ?

when all motor units are recruited

when is the largest force reached in a motor unit recruitment graph?

decrease in force production

eventually in the MUR graph, stimulus intensity will max out when all motor units have been recruited, but the stimuli will continue coming, which leads to …?

motor units recruited

larger mass leads to an increase in …?

number of motor units recruited

By recruiting stimulus intensity, what are you changing to increase force?

the force would increase because more motor units are being recruited

what would happen if stimulus intensity increased but stimulus frequency stayed the same?

wave summation

Which graph occurs when a second stimulus arrives before the muscle has completely recovered from the first twitch?

added

in the wave summation graph, because the muscle is not fully relaxed, the force from the next twitch is …? to the force that remains?

the cytoplasm

during wave summation, where does the amount of calcium remain elevated between stimuli?

wave summation

the result of which graph is an increase in force of contraction

stimulus frequency

in wave summation what is being changed to increase force?

force would increase through summation

what would happen if stimulus frequency increased by the number of recruited motor unit stayed the same?

force would increase through summation

what would happen if all motor units were recruited, but stimulus frequency continued to increase?

length tension curve

which graph describes how starting muscle length affects the force it can produce?

overlap

in the length tension curve, at optimal resting length, actin and myosin have the best …? for forming connections

excessive

if the muscle is too shortened, the overlap of the filaments is …?

there is less overlap

if a muscle is stretched too far how does the overlap of actin and myosin look?

decreased

less effective connections between actin and myosin result in …? force

muscle length

according to the length tension curve, what changes to allow for increased force of muscle?

length tension curve

all muscle have which graph?

tetanus

during which graph does the muscle receive a stimulus at a very rapid frequency?

relax

in tetanus, because of the rapid stimuli, the muscle has no time to ...? between stimuli

skeletal

Tetanus can only occur in what kind of muscle?

in the cytoplasm because calcium is being released again from the SR before it is pumped back

in tetanus where does calcium remain elevated and why?

Tetanus

which graph produces a sustained, high level of muscle contraction?

recruitment

… changes how many motor units are active

frequency

… changes how close together stimuli occur

length tension

… changes the muscles starting length

recruitment, frequency, length tension

Three ways skeletal muscle can change gits force:

twitches

every time there is a length change in muscle cell, an electrical signal occurs to open or change the channels, these quick electrical signals are called …?

optimal

the greatest force is produced when the sarcomere is at its …? length