Lecture 27 Flashcards
What are the two energy sources for contraction?
- Anaerobic
- Aerobic
What are the two energy sources for contraction?
- Anaerobic
- Aerobic
What are the features of Anaerobic energy source?
- short term
- fast energy production
- no oxygen required
What are the features of aerobic energy source?
- long term, steady
- slower energy production
- oxygen required
What produces more ATP out of aerobic and anaerobic?
Aerobic
How long does ATP stores provide energy?
2-4 seconds
How long does CP provide energy for ATP resynthesis?
20 seconds
What are the three muscle fiber types?
- red
- white
- intermediate
What are the features of the red muscle fibers?
- high myoglobin
- high aerobic enzymes
- slow
What is myoglobin?
A red pigment caused by the oxygen iron binding
Why are red muscle fibers slow?
Because they have the myosin type 1
What are the features of white muscle fibers?
- Low myoglobin
- Low aerobic enzymes
- Fast
Why are white muscle fibers fast?
Because they have the myosin type 11x
What are the features like in the intermediate muscle fibers?
In between red and white
What are the features like in the intermediate muscle fibers?
In between red and white
What is slow in the red muscle fibers?
- interaction rate with actin
- force production
- energy consumption
What are red muscle fibers sustained by?
aerobic metabolism
What is fast in the white muscle fibers?
- interaction rate with actin
- force production
- energy consumption
What are white muscle fibers sustained by?
anaerobic metabolism
What are white muscle fibers sustained by?
anaerobic metabolism
What causes a twitch?
A single electrical stimulation of a muscle
a single activation of many motor units
Why does repeated stimuli cause increasing levels of tension?
- sustained higher levels of Ca2+
- actin-myosin interaction become more sensitive to Ca2+
- increased heat produces more tension
What causes summation?
Rapidly repeated stimuli causes even higher levels of tension
What causes summation?
Rapidly repeated stimuli causes even higher levels of tension
