Muscle 2 Flashcards
Describe what determines the length tension relationship
it is dependent on the actin and myosin overlap
tension generated when all cross bridges are attached
Optimum force generated as all cross bridges are formed
Increased length of sarcomere tension generated
tension has decreased generation as less cross bridge cycles are occuring
decreased length of sarcomere
tension generated
generation of tension is decreased as areas of the myosin where their is no myosin head= decreased force
sarcomeres completely overlap and meet the z disc
what tension is generated
no tension is generated as the actin begin to overlap which interfere with the myosin.
therefore no tension is generated
equation for total tension
active + passive force
What is passive tension
generated from the elastic forces which resist
what are active tension
the length of the sarcomere
what is a motor unit
motor neuron and all the muscle fibers it innervates
describe ACH release into the neuromuscular junction
- Action poetntial travels down the motor neuron
- CA enters the axon via the axon terminals
- ACh vesicles are triggered= exiting of the terminal membrane into the synaptic cleft
Excitation contraction coupling part 1 sequence
- ACh released into the synaptic cleft
- Ach activation of the receptors
- A muscle action potential is generated
effects of ACh are short
what enzyme breaks it down
acetylcholine esterase
Muscle action potential triggered
describe
(part 1 excitation contraction coupling)
- enough ligand gated channels open= threshold
- Voltage gated NA ions open= action potenital generated
- AP is propagated throughout the sarcolema and into the T tubules
state the sequence of part 2 excitation contraction coupling
- Calcium is released from the SR
2. Ca binds with tropinin
describe calcium released from the SR
- AP travels down the sarcoelma into the T tubules
2. Voltage gated CA channels are activated in the SR and release CA into the muscle cytosol
describe Calcium binding to Actin
if the calcium conc meets threshold Ca will bind to Tropinin and the cross bridge cycle will be able to occur
What occurs after calcium binds to actin
CROSS BRDIGE CYCLE
what occurs last within the excitation contraction coupling
Contraction ends when Ca conc falls
describe Contraction ends when Ca conc falls
Ca is actively pumped back into the SR via the Ca2+ ATPase pump
Conc of CA decreases causing the myosin binding site to be covered by the tropomyosin
Creatine Phosphate is activated when
acts as a ATP store
Creatine phosphate + ADP= creatine + ATP
when is Creatine Phosphate used
anaerobic exercise
Type 1 muscle fibres
slow efficient aerobic cells
Type 2 muscle fibres
fast large fibers= great forces
Regulation of force is dependent on what
rate of stimulation of individual motor unit
number of motor units recruited
Increased frequency of action potential causes what
Temporal summation which is a grater force as the muscle is unable to relax= GREATER CONTRACTION
which motor units are recruited first
fatigue resistant
