Muscle Contraction Flashcards
T/F
One motor nueron for one motor fiber
FALSE
Motor neuron can innervate many motor fibers.
Between what proteins does invagination allow the interaction?
Between DHPR (from the sarcolemma) and RYR (from the reticulum).
Where does DHPR works as a Ca2+ channel?
In the cardiac muscle.
Makes the action potential longer.
How is the calcium pump that gives Ca++ to the SER called?
SERCA
Soft Endoplasmic Reticulum CAlcium
Short contraction
Which ones are the thin filaments?
Actin
Which ones are the thick filaments?
Myosin
Formed by a head and a tail.
What is the cause of Rigor Mortis?
The lack of energy to allow the release of myosin from actin.
Some muscle spasms (tetani) can be caused by…
Hypocalcemia
Low Ca+2 can affect K+ channels (they close), spontanous depolarizaton.
To sarcomeres must be bound so there’s correct contraction?
To the muscle cell membrane and the ECM.
The contraction must be transmitted to tendons (Connectiv Tissue).
Which protein keeps in place thick filaments (myosin)?
Titin
Which protein keeps in place thin filaments (actin)?
Alpha-actinin
Which protein binds integrins to myofibrils?
Desmin
Which protein binds the ECM (collagen) to the sarcolemma (muscle cell)?
Integrins
What is a costamere?
A protein that connects the sarcomere (myofibrils) to the cell membrane (sarcolemma).
Which protein links actin to the cytoskeleton?
Dystrophins and DGC.
