Lecture 5 - Skel Musc. Contraction Flashcards
The plasma membrane of the muscle fiber is called the? 2 names
Sarcolemma or plasmolemma
Calcium is stored in ?
SR
The contractile unit is called the?
Sarcomere
The large to small organization of a muscle? 5 parts
Muscle - Fasciculus - MyoFiber - MyoFibril - MicroFilament
What holds the Sarcomere together that runs down the middle of the Sarcomere Z line to Z line and through the myosin?
Titan
Fluid that surrounds the MyoFibrils?
Sarcoplasm
which bands/lines change length and which stay the same?
Z A stay same or ZAme
H I change.
which chains of the myosin control the function of the myosin head? light or heavy
Light
What unique function does myosin have that allows it to complete this contraction process.? think enzyme
IT can function as an ATPase enzyme and cleave ATP for E?
Ca is release from the _________ and binds to ________ ?
SR
Troponin complex on F - Actin
define summation and tetany
Summation is where the # contractions are additive to increase overall muscle contraction
Tetany occurs when The frequency of contraction is so high that there is only contraction and no relaxtion. Also no additional increase in frequency has any effect. Ca ions are maintained in the muscle Sarcoplasm.
- what does multiple fiber summation come from?
- frequency summation?
which one leads to tetany?
- an INCREASE IN # OF motor units firing.
2. an increase in Frequency of Contractions and leads to tetanization.
Which part of the muscle can increase in number ?
The the Myofibril.
define isometric?
define isotonic and its 2 types?
isometric, Change in tension with NO change in length
isotonic, Constant tension with change in length.
concentric, shortening
eccentric, lengthing
for a muscle contraction, Work =
W = Load x Distance
Which covering membrane is continuous with the tendon of a muscle?
epimysium
moment =
and at equilibrium
m = F L force x lever arm
F L cw = F L ccw
Calcium Sequestrin: explain location and what it does?
Its inside of the Sarcoplasmic Reticulum and by binding Ca in the SR its maintains an optimal level of Ca that affects the concentration gradient so that the Ca pumps don’t have to work so hard.
When is ATP used for moving Ca? from where to where, what is acronym for the pump?
SERCA* uses ATP to pump calcium back into the SR from the sarcoplasm. (Sarcoplasmic Reticulum Calcium ATPase)
Through what does Ca leave the SR?
Active or passive?
Ryanodine channels
Passive
Match the following into 2 groups?
Fast twitch, Slow twitch, white/red, Inc./Dec. Myoglobin, Inc./Dec. ATPase, Gastroc/soleus
Fast twitch, white, Dec. Myoglobin, Inc. Atpase, Gastroc.
those left match.
T Tubules are located precisely in the sarcomere at what interface?
They have what directly on both sides of them?
And therefore they are referred to as a _______ based on this arrangement?
located precisely at A band and I band Interface
with terminal cisterne of SR on both sides
forming what is referred to as a TRIAD
Within a muscle, the all or none principle applies to the what? and this complex is made up of what?
Motor unit - is made up of one neuron and all the myofibrils it sends an action potential too.
Lost muscle tissue will be replaced by?
scar tissue
A motor unit consists of what 2 things?
A neuron and the myofibers it innervates
At birth the number of _________ cannot be increased?
myoFibers
Whats in the middle of a first, second and third class lever system respectively?
1st - Fulcrum (atlas as fulcrum, neck muscles as
2nd - Resistance or OUT force (tip toe)
3rd - Effort or IN force (drinking)
which levers have forces on the same sides and in same directions?
2nd and third.
