Muscle Physiology Flashcards
What is the order of muscle size break down
muscle -> muscle fiber -> muscle febrile -> myofibrile
The myofibril is considered the contractile unit because it contains the _______
sarcomere
_-___________ the thin filament
actin
_____________ the thick filament
myosin
Actin is wrapped by protein structures ______________
troponin and tropomyosin
myosin is composed of ______________ and ______________
myosin light chain and a protein head
___________ blocked the binding of the myosin head to actin
tropomyosin
___________ is the binding site of calcium so that the muscle can contract
troponin
__ is only produced when the muscle is active/ contracted. This occurs when the muscle is stimulated
tension
________________ the myosin (thick filament) of muscle fibers slide past the actin (thin) filaments during muscle contraction, while the two groups of filaments remain relatively constant length
sliding filament hypothesis
maximum tension (force produced) occurs when _____________
thick and thin filaments overlap
___________ the tension force produced when a muscle is extended past resting length
active tension
___________ the tension force produced when the muscle is at its resting length
passive tension
the total tension is
the sum of active and passive tension
__________ is necessary to activate contraction
calcium
__________ is necessary to both activate and deactivate muscle contraction
ATP
When ATP is removed, we have __________
rigger mortis. Stiffening of a muscle
what are the steps of the power stroke
- troponin binds gto calcium pulling tropomyosin away from the actin bindings site
- myosin binds to ATP to use the phosphorylation energy to bind to actin and release ADP+P
- Myosin binds to ATP again causing the actin and myosin to unbind
- The process must repeat itself
___________ occurs when the force/tension acting on the muscle remaining constant while the length of the muscle changes
isotonic contraction
If the weight hanging on the muscle is too heavy there is no ____________
shortening velocity
The maximum mechanical power occurs at ________________________
some arbitrary intermediate shortening velocity
the hill equation shows that you can not arbitrarily _____________
increase one value and expect the shortening velocity to increase
The sarcoplasmic reticulum is structurally optimal to ______________________
deliver calcium
The sarcoplasmic reticulum is electrically deactivated by a ___________________________
depolarization of motor neuron to release calcium
after depolarization of the mortor neuron calcium can bind ________________
troponin
___________ is crucial for muscle contraction (space of electromechanical coupling_)))))))))
calcium diffusion
scientists use _______________ calcium activated flournse to show the changes in calcium concentration
furaptra
gulf toadfish uses ___________________ to sing and attract females
muscles ion the swim Blatter
The fast contraction of muscle in the swim bladder is called ____________ because they are very short contractions
twitch
twitch, short contractions are not __________________
ATP limiting and are low force
The swim Bladder can be used for ________________
rapd escape mechanisms or slow swimming menuvers
_________ has a whitish color due to low vascularization rapid escape
glycortic
____________ is used for slow swimming because of high vascularization
oxidative metabolism
_____________ max tension occurs before max length/during stretch
clockwise loop
______________ max tension occurs during shortening
counterclockwise
The switch in a work loop from clockwise to counterclockwise occurs because the ___________________
negative and positive work switch signs
negative work is
the work input required to shorten the muscle
positive work is
the work output during shortening
Net work cycle is a ______________
net positive
work input occurs via
passive tension
work output occurs via
passive and active tension
What are the 5 characteristics of fast muscles
- rapid Ca++ cycling
- lots of Sarcoplasmic reticulum
- fewer contractile elements
- low force production
What are the 5 characteristics of slow muscle
- slow ca cycling
- little Sarcoplasmic reticulum
- more contractile elements
- higher force production
Toadfish swim Blatter use
fast muscle
regular skeletal muscle uses
slow muscles
high force and high frequency for _______________
flight in small insects
Flight muscle in insects are
stretch activated
Why is insect flight energetically costly
high force and high frequency
Insect flight muscles are
- indirect
- asynchronous
- stretch activated
- little SR more contractile elements packed for full power
- Insects can only fly at a frequency that matches the thorax frequency
the thorax ____________ as a result of wing movement
resinates
muscles are organized into ____________
elevators and depressors
insect flight muscles are organized __________ meaning when one muscle contract the other relaxes
orthogonally
During each stage of flight is either the __________________
dorsal ventral muscles are act or dorsal lateral muscle
