1. Muscular System
By Katie Ust

2. Function
The main function is to provide mobility, strength , head production, and shock absorption to the body

3. 3 types of muscle
Skeletal Muscle – moves us around and is responsible for behaviors. Attached to bones
Cardiac Muscle – found in the heart. Acts like rhythmic smooth muscle
Smooth Muscle - controlled by the autonomic nervous system. Can be inactive and respond to neural stimulation/hormones or can be rhythmic

4. Sliding Filament Model
Calcium ions are released and bond to troponin. Myosin is used as a molecular motor and can then bind to passive actin filaments
After a strong bond the two undergo isomerization
ATP binds and allows myosin to detach from actin
ATP hydrolysis recharges myosin head so it can bind to actin again

5. (Cont.)
Sarcomeres are flanked by two actin filaments and are drawn in and shortened.
Sarcomeres are connected by bridges which anchor actin filaments with reversed polarity
Sarcomeres are arranged so they simultaneously contract so that force is transmitted to the fiber ends.

6. Muscular Dystrophy
Muscles are greatly weakened and there is muscle loss
Genetic disease
Treatment includes physical and speech therapy, surgery, medications, but there is to cure.

7. Sources Epix.net/~tcannon1/physioweek4.htm
En.wikipedia.org/wiki/Sliding_filament_model