4 steps of skeletal muscle to contract
1. EVents at neuromuscular junction
2. Muscle fiber excitation
3. Excitation - contraction
4. Cross bridge cycling
Making ATP
Creatine phosphate that can lone over and adp creates atp. (
Anaerobic Pathway
without oxygen, will help build up adp ( 2 atp per glucose )
Aerobic Pathway.
uses oxygen and glucose
produces 32 atp per glucose lots of energy but takes a while
3 things ATP is responbile for muscle contraction
1. Move and detach cross bridge
2. pump calcum back into SR Pumps NA+ out of and K+ back into cell
Difference betwn. Ana & Aerobic Pathway.
Ana = No Oxygen
Aerobic = With Oxygen
How many ATP is made during the Anerobic Pathway & Aerobic
2 & 32
Providing Energy for Contraction
Anaerobic
& Aerobic
Muscle Fatigue
Physiological inability to contract despite continued stimulation
Possible Causes Include : Ionic imbalances can cause fatigue or levels of K+ and Na+
Decreased ATP and Increased Magnesium
As ATP drops, magnesium levels increases and this can interefer with voltafe sensitive T tubule proteins
Decreased glycogen : Lack of ATP is rarely reason for fatigue, except severe
Clinical
Muscles must be active to remain healthy
- Disuse atrophy ( degeneration and loss of muscle tissue )
- due to immobilization or loss of neural stimulation
- Muscle strength can decline 5% per day
Myasthenia gravis
A communication problem at nerves and muscles resuls in muscles wekness and muscle fatigue
Lambert Eaton syndrom
A condition in which the bodys immune system attacks.