Quiz 7 guide + smooth muscle lab preview + grades

Quiz 7 guide

Isotonic muscle contraction

- Once again should know difference between isotonic muscle contraction and isometric muscle contraction.
- Why or how does isotonic muscle contraction.
- How does load affect contraction, speed of contraction and change in muscle length. From this you can calculate work.
- The general trend of graphs: relationship of muscle shortening to load, isotonic contraction with increasing, relationship of velocity of contraction and load.
- Remember how you calculate the velocity [v=y(distance)/x(time)] and work (work= force x distance).
- Change in the set up of isometric contraction and isotonic contraction. This means if someone puts a setup on the exam with muscle you should know what experiment they are referring to. Also another difference in the set up is that of 5mm adjustment. You use 5g weight in isometric and the knob in isotonic contraction.


ATP and Muscle contraction

- The introduction section of contraction. The entire theory behind how the contraction occurs. I really prefer you read the sliding filament theory in your textbook (pg: 291-292). On further pages you will get description of the contraction cycle. While reading I would also recommend to take a look on the animation in your Interactive Physiology CD-Rom that came along with your textbook.
- Optional: And since you have reached these pages why not to go ahead and read on muscle tension, and isotonic & isometric contraction.
- Plus the results: What happened when you added ATP to the muscle.
- I will not ask something like what is the % contraction of a muscle that you might be calculating using the values of original length and post-treatment lengths given to you. However for the final exam I cannot assure anything so just remember it.
- Good animation of above process available online at http://www.blackwellpublishing.com/matthews/myosin.html
Thanks to Emily for sharing this.





Properties of smooth muscle action lab- preview

- We shall be using small intestine of mice to understand action of smooth muscle. This means that how smooth muscle is involved during digestion of food through small intestine (theoretically), how nervous system controls this process with help of different neurotransmitters (experimentation).
- Since you are accustomed to the programs that we use it should not be a big problem. The only this that you need to take care of is always maintain the temprature at 37 C of tyrodes solution inside the beaker where you have the piece of small intestine.


Class averages

Quiz 5 (Membrane potential & Excel)
Avg: 76.47
High: 90
Low: 34

Worksheet (Isometric contraction)
Avg: 92.94
High: 95
Low: 90