Muscle Part B

Question 1

What are the Principles of Muscle Mechanics?

Answer 1

1.Same principles apply to contraction of a
single fiber and a whole muscle
2.Contraction produces tension, the force
exerted on the load or object to be moved
3.Contraction does not always shorten a
muscle: Isometric and Isotonic
4. Force and duration of contraction vary in response to stimuli of different frequencies
and intensities

Question 2

Contraction produces tension, the force

exerted on the load or object to be moved

Question 3

____?no shortening; muscle

tension increases but does not exceed the load

Answer 3

Isometric contraction

Question 4

____?muscle shortens

because muscle tension exceeds the load

Answer 4

Isotonic contraction

Question 5

Muscle changes in length and moves the load

____? contractions are either concentric or eccentric:

Answer 5

Isotonic Contractions

Question 5

Muscle changes in length and moves the load

____? contractions are either concentric or eccentric:

Answer 5

Isotonic Contractions

Question 6

When the muscle

shortens and does work is call

Answer 6

Concentric

Question 7

When the muscle

shortens and does work is call

Answer 7

Concentric

Question 8

When the muscle contracts

as it lengthens it becomes

Answer 8

Eccentric

Question 9

When The load is greater than the tension the muscle is able to develop, what Contraction does it becomes?

Answer 9

Isometric contractions

Question 9

When The load is greater than the tension the muscle is able to develop, what Contraction does it becomes?

Answer 9

Isometric contractions

Question 10

Tension increases to the muscle’s capacity, but the muscle neither shortens nor lengthens what contractions does it become?

Answer 10

Isometric Contractions

Question 10

Tension increases to the muscle’s capacity, but the muscle neither shortens nor lengthens what contractions does it become?

Answer 10

Isometric Contractions

Question 11

___? a motor neuron and all (four to

several hundred) muscle fibers it supplies

Answer 11

Motor unit

Question 12

___? a motor neuron and all (four to

several hundred) muscle fibers it supplies

Answer 12

Motor unit

Question 13

motor units in muscles that control fine

movements (fingers, eyes)

Answer 13

Small Motor Unit

Question 14

motor units in large weight-bearing

muscles (thighs, hips)

Answer 14

Large Motor unit

Question 15

____?is a Response of a muscle to a single, brief threshold stimulus

Answer 15

Muscle Twitch

Question 15

____?is a Response of a muscle to a single, brief threshold stimulus

Answer 15

Muscle Twitch

Question 16

A single stimulus results in a single contraction response of a ____?

Answer 16

Muscle twitch

Question 16

A single stimulus results in a single contraction response of a ____?

Answer 16

Muscle twitch

Question 17

Three phases of a twitch are

Answer 17

1. Latent period: events of excitation-
contraction coupling
2. Period of contraction: cross bridge 
formation; tension increases
3. Period of relaxation: Ca2+ reentry into the 
SR; tension declines to zero

Question 17

Define: Increase frequency of stimulus

Answer 17

when muscle does not have time to completely relax between

stimuli

Question 18

when ATP is the only source used directly for contractile activities it becomes?

Answer 18

Muscle Metabolism

Question 18

when ATP is the only source used directly for contractile activities it becomes?

Answer 18

Muscle Metabolism

Question 19

The 3 short term for Muscle Metabolism

Answer 19

Cellular levels = ATP stored in cell
* first 0 – 6 seconds of activity; good
source for shuttling Ca+ back into SR

Creatinine phosphate (energy rich
molecule found in muscle, synthesized from extra ATP) =
*synthesizes ATP from ADP; creates 15
seconds worth of energy; good source for quick burst
of energy or “sprint”.

Question 19

The 3 short term for Muscle Metabolism

Answer 19

Cellular levels = ATP stored in cell
* first 0 – 6 seconds of activity; good
source for shuttling Ca+ back into SR

Creatinine phosphate (energy rich
molecule found in muscle, synthesized from extra ATP) =
*synthesizes ATP from ADP; creates 15
seconds worth of energy; good source for quick burst
of energy or “sprint”

Glycogen in muscles= energy source for
30 – 40 seconds.

Question 20

____ATP stored in cell
* first 0 – 6 seconds of activity; good
source for shuttling Ca+ back into SR (Short term)

Answer 20

Cellular Levels

Question 21

(energy rich
molecule found in muscle, synthesized from extra ATP) synthesizes ATP from ADP; creates 15 seconds worth of energy; good source for quick burst
of energy or “sprint”. (short term)

Answer 21

creatinine phosphate

Question 22

____? energy source for

30 – 40 seconds (short term)

Answer 22

Glycogen in muscle

Question 23

The 2 Long Term for Mechanical

Answer 23

1. aerobic respiration (use oxygen)
   * after 10 minutes of activity, aerobic
   respiration provides 90% of the necessary ATP
2. anaerobic cellular respiration (no
   oxygen available)
   *lasts 30 – 40 seconds; lactic acid is
   the final product

Question 24

after 10 minutes of activity, aerobic

respiration provides 90% of the necessary ATP is becomes (2 long term)

Answer 24

aerobic

Question 25

lasts 30 – 40 seconds; lactic acid is

the final product (long term (2 long term)

Answer 25

anaerobic cellular respiration (no

oxygen available)

Question 26

40% of the energy released in muscle
activity is useful as work
•Remaining energy (60%) given off as heat

Answer 26

Heat Production During Muscle Activity