Lab Quiz 2 - 1 Flashcards
A single muscle contraction is called:
A twitch
a single action potential
Type I muscle fibers:
Slow twitch Primarily aerobic lots of mitochondria lots of myoglobin lots of capillaries
Myoglobin:
red protein containing heme which stores oxygen in muscles
Type II muscle fibers:
Fast twitch Primarily anaerobic Few of mitochondria little myoglobin Few capillaries
Tropomyosin:
Troponin is attached to it.
Ca2+ binding to tropomyosin shifts it away from active site of myosin
Troponin:
Blocks crossbridge formation.
Binds to tropomyosin
What is required for muscle contraction to occur?
ATP
Ca2+
Magnesium
Example of a:
- Fast Twitch:
- Slow Twitch:
- Fast Twitch:
Eye - Slow Twitch:
Soleus in lower calf
Motor unit:
Somatic motor neuron, and all muscle fibers it innervates
Motor unit summation:
- Define:
- How does it work?
- Define:
Gradual addition of muscle fibers (one motor unit at a time) - How does it work?
Recruits slow twitch and smaller muscle fibers first, increased signal strength causes additional recruitment of fast twitch muscle fibers
Wave (temporal) summation (muscular innervation):
Muscle contractions build on each other. As they come more and more quickly, the muscle no longer has time to relax. It becomes in a continual state of contraction: tetanus
Tetanus:
Continual state of contraction, results from temporal summation
A sustained contraction (multiple action potentials)
Products of muscles running in:
- Anaerobic:
- Aerobic:
- Anaerobic:
Lactic acid - Aerobic:
CO2 and H2O
Lactic acid and muscle fatigue:
- Define:
- Duration:
- Utilization of lactic acid:
- Define: Lowers pH, causing enzymes in muscle fibers to have reduced activity - Duration: Does not cause longterm fatigue - Utilization of lactic acid: Shuttled to liver for gluconeogenesis
Muscle fatigue:
The inability to sustain a contraction
Glycogen depletion and fatigue:
This will cause fatigue, in longterm
Why can sprinters perform multiple heats in a day but long distance runners cannot.
Sprinters will not deplete glycogen stores, they will simply cause lactic acid build up, which will be taken care of by the liver (gluconeogenesis)
Long distance runners cannot, because glycogen stores will be depleted
What is the device we squeezed in class called?
- What is the range for a male?
- What is the range for a female?
Hand dynamometer - What is the range for a male? 40 - 65 kg (50 average) - What is the range for a female? 20 - 38 (28 average)
What is the fastest number of squeezes I can do in a second?
Why?
~5
< 10
Because necessary time to relax before firing again (Ca2+ must go out and back in)
Parts of a sarcomere:
IZIAHMHA I Z: actin connecting middle line I: Actin only A: All of myosin H: only myosin (where it doesn't overlap with actin) M: middle of myosin H A
Glycerination of muscle has what effect?
Makes membrane permeable
Disrupts the tropomyosin-troponin complex (making Ca2+ unnecessary for muscle contraction)
Anterior:
Posterior:
Anterior (Rostral):
Towards face/front of brain
Posterior (Caudal):
Towards back of head/back of brain