Bio107-ch9&10pt3 Flashcards
Shortening
Occurs when the tension generated by the cross bridge exceeds forces opposing shortening
Contraction
The muscles are doing work and shortening the sacromere
Decreasing the h zone
Contraction ends when
The cross bridge becomes inactive, the tension generated declines, and relaxation is induced
Motor unit
A motor neuron and all the muscle fibers it supplies
Multiple motor unit summation (2)
- Increase the strength of the stimuli
2. Frequency of stimulation is constant
Wave summation (2)
- Increase the frequency of the stimulus
2. Strength of the stimulus is constant
Wave summation can cause (2)
Muscle spasms or tetnus
Isometric contraction
Increasing force of contraction, length of muscle constant
Wall sits
Isotonic contraction
Force of contraction stays constant, length of muscles decreases
Lifting weights
Concentric contractions- isotonic
Muscles shortens and does work
Eccentric contraction- isotonic
Muscle contracts as it lengthens
_____ is the only source used directly for contractile activity
ATP
Anaerobic glycolysis
Body starts breaking down a 12 carbon sugar
Anaerobic glycolysis- if o2 present:
ATP will continue to produce
Glycolysis yields little ATP
Anaerobic glycolysis- no o2 available
ATP production stops
Muscle builds up lactic acid
Aerobic respiration
“Krebs cycle” - goes through process twice
If O2, then on to electron transport chain
Yields little ATP
Muscles need ____ in order to work
ATP
Stored ATP does not _____
Last long
All 3 systems produce ____-____ ATP per _____ that we break down
32-36
Glucose
The more _____ a muscle has, the more ____ can be produced
Mitochondria
ATP
Hypertrophy
Increase of the muscle mass
Working out
Atrophy
Decrease in the mass of a muscle
