A 13 excitation/contraction coupling Flashcards
what are the voltage sensor in muscle T-tublules called?
DHPR or Dihydropyridine receptor. (note that very little calcium actually travels through it) It is an L-type receptor.
what is the S.R calcuim release channel called?
Ryanodine receptors
what binds up calcium in the sarcoplasmic reticulum?
Calsequestrin (it can bind up to 50 Ca+)
what transports calcium in the cytoplasm back into the SR?
Ca+ ATPase (SERCA)
What causes malignant hyperthermia?
It is caused by a faulty Ryanodine receptor that allows too much calcium to escape into the cytoplasm. Can lead to hyperKalemia (high potassium)
What stops muscle contraction?
SERCA (AKA Ca+ ATPase)
which part of the SR are the Ryanodine receptors located?
at the terminal cisternae
what is the longitudinal reticulum?
The part of the sarcoplasmic reticulum that is found between the terminal cisternae and where Ca+ATPase is located.
What is dantroline?
an antagonist for the ryanodine receptors that helps to prevent malignant hyperthermia.
The terminal cisternae run between which two structures in the sarcomere?
the I band and the A band.
what is the junctional tetrad?
DHPR + T-tubule
Ryandine + Terminal cisternae
T/F The ryanodine receptor requires ATP to open?
False, no atp is required.
What are two other substances that can cause the release of Calcium from the SR?
Caffeine
High Ca+ outflow through another ryanodine receptor
why is it possible for tetanus to occur?
because the uptake of calcium is slower than its release for the SR
what is muscular dysgenesis?
A condition found in mice that does not permit the DHPR to open…= no contraction.
