muscle mechanisms

Question 1

the muscle force at any time is proportional to___. This regulated by what three things?

Answer 1

number of attached cross-bridges. Ca, length, velocity

Question 2

what is the length-force relationship

Answer 2

in abundance of Ca, more overlap means greater force until actin start interfering w/ each other. Once you stretch a lot the elastic fibers become important and generate lots of force

Question 3

what is the velocity-force relationship

Answer 3

increased shortening speed=decreased force. increased lengthening speed= increased force

Question 4

the greatest force is achievable with what type of contraction? Implications? refered to as?

Answer 4

eccentric. smooths out oscillations. viscosity

Question 5

why is fat such a high density form of storing energy?

Answer 5

because it excludes water. protein and carbs do not

Question 6

sources of muscle energy and approx times and power

Answer 6

ATP (first second), CP (1-10 sec), Anaerobic glycolysis (10-100 sec), aerobic glycolysis (15 seconds on), aerobic fat (100 sec on). Power decreases with each

Question 7

How many neurons innervate each fiber?

Answer 7

one.

Question 8

type 1 fibers

Answer 8

slow twitch. high density mitochondria, low ATP usage. Fatigue resistant

Question 9

type 2a fibers

Answer 9

fast fatigue resistant

Question 10

type 2x

Answer 10

fast fatigable. low density mitchondria, more rapid usage of ATP. More fibers recruited by stimulation