Chapter 12 (Part 3) Flashcards
what is the function of transverse tubules?
how we bring things inside a muscle fiber
what is the function of the sarcoplasmic reticulum within the myofibril?
store calcium
what is a transverse tubule
invagination of the sarcolemma, continuation of the cell surface
protein filaments make up a
sarcomere
sarcomeres make up a
myofibril
myofibrils make up a
muscle fiber
muscle fibers make up a
fasicle
fascicles make up a
muscle body
a muscle body is a collection of
fascicles
a fascicle is a group of
muscle fibers
a muscle fiber is a group of
myofibrils
a myofibril is a group of
sarcomere
a sarcomere is a group of
protein filaments
what is the smallest contractile unit of the muscle
sarcomeres
acetylcholine binds to what kind of receptors?
nicotinic cholinergic
where are the receptors found that acetylcholine binds to?
on the muscle fiber sarcolemma
what happens when acetylcholine binds to receptors on the muscle fiber sarcolemma?
the sarcolemma depolarizes
when the sarcolemma depolarizes, how is the signal spread throughout the muscle fiber?
depolarization opens voltage-gated sodium channels across the sarcolemma and down into the transverse tubules
when the sarcolemma depolarizes, what is the function of dihydropyridine receptors?
open ryanodine channels to release Ca+2 from the sarcoplasmic reticulum and into the sarcoplasm
what is the sarcolemma?
muscle fiber plasma membrane
what is the sarcoplasm?
muscle fiber interior
where are dihydropyridine receptors found?
attached to ryanodine Ca+2 channels on the sarcoplasmic reticulum
when the sarcolemma depolarizes, what is the functino of ryanodine receptors?
release Ca+2 from the sarcoplasmic reticulum and into the sarcoplasm
when the sarcolemma depolarizes, where does calcium that gets released from the sarcoplasmic reticulum bind?
to troponin
