MSKS Physiology Lecture 3_Muscle Phys Part 2

Question 1

Describe the force velocity relationship

Answer 1

The lower the load, the faster the shortening velocity.

Question 2

how does a myofiber change with Endurance training, resistance training, and disuse?

Answer 2

Question 3

What is total tention?

Answer 3

It is the sumation of active and passive tention

Question 4

What are the two types of force summation?

Answer 4

Question 5

What are the three pathways for generating ATP during muscle activity and how long can each pathway provide energy?

Answer 5

Question 6

How do you increase muscle force? How do you increase muscle velocity?

Answer 6

Question 7

What are the three periods of muscle contraction?

Answer 7

1) Latent Period - Action potential is triggered (ACh releaased by the nerve and depolarization of the sarcolemma to the T tubules)
2) Contraction Period - As the T tubules are depolarized they open voltage gated calcium channles on the terminal cisternae which releases calcium from the SR. This Ca binds to troponin C causes a conformational change in tropomyosin which allows myosin to bind and for contractions to occure.
3) Relaxation Period - muscles relax as Ca is pumped back into the SR

Question 8

Describe isotonic consentric, isotonic eccentric, and isometric muscel contractions

Answer 8

Question 9

Define the following properties for Type 1 and 2 motor units

Answer 9