1. MUSCULAR SYSTEM I pp

2. FUNCTION
Support, movement, and protection

3. TYPES skeletal – muscles that move bones (voluntary)
smooth – involuntary muscles that protect organs
cardiac – involuntary muscles found only in heart

4. MUSCLE STRUCTURE
myofibril muscle cell (fiber)fascicle muscle

5. Two types of proteins (actin and myosin) involved
actin + myosin  myofibril
myofibril attaches to Z line
sarcomere: functional unit from Z line to Z line

6. MUSCLE CONTRACTION

7. contraction: shortening of sarcomere between Z –lines
myosin “heads” walk along the actin
this requires ATP to walk and to release the myosin after walking

9. ENERGY
Aerobic respiration: breaking down organic compounds to release energy to be used by the body
OCCURS:
1. when oxygen is present
2. in the mitochondria
PRODUCES:
ATP

10. MUSCLE FATIGUE
The inability to contract the muscle due to the lack of ATP
a contraction occurs when “heads” walk along the actin
The walking requires ATP to contract and release the muscle

11. Look at p 929 #7. Define parts of picture 1-4.
Read
Do problems p 922 # 1-4, 9, 10
Look at p 929 #7. Define parts of picture 1-4.
Is this muscle elongated or contracted?