Biology II - Muscle System: Neuromuscular Junction Background

Biology II

cells are made of smaller parts called

organelles

how many organelles do muscle fibers have and name them

5

myofribil

sarcolemma

sarcoplasmic reticulum

t-tubules

receptors

myofibril

the individual proteins that make up part of a muscle fiber

sarcolemma

the muscle fiber cell membrane

sarcoplasmic reticulum

regulates level of calcium ions (Ca2+) in the muscle fiber

releases calcium ions when a muscle fiber is stimulated by an electrical impulse

does not release calcium ions when there is no electrical impulse

t-tubules

part of the sarcolemma that protrudes deep into the muscle fiber interior

allows electrical impulses to reach the deepest parts of the sarcoplasmic reticulum

receptors

binding sites on the muscle fiber that receive neurotransmitters