Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
a muscle fiber is composed of thousands of stacked, cylindrical, contractile structures called
|
myofibrils
|
|
|
each myofibril consists of smaller contractile units called
|
sarcomeres
|
|
|
each sarcomere contains an orderly arrangement of rod-like protein filaments called
|
myofilaments
|
|
|
2 types of myofilaments
|
myosin protein (thick) - actin protein (thin)
|
|
|
what give skeletal muscle it's striated appearance
|
actin + myosin
|
|
|
sarcoplasm description/function
|
similar to cytoplasm - contains myoglobin
|
|
|
myoglobin description/function
|
red protein pigment - stores oxygen
|
|
|
sarcolemma description/function
|
plasma membrane of muscle fiber - carries impulses initiated by nerves
|
|
|
t-tubules description/function
|
extensions of sarcolemma - conduct impulses deep into muscle fiber
|
|
|
sarcoplasmic reticulum description/function
|
system of ER surrounding each myofibril - stores calcium
|
|
|
what are calcium ions need for
|
muscle contraction
|
|
|
terminal cisternae description/location
|
widened regions of sarcoplasmic reticulum - surrounds each t-tubule
|
|
|
sarcomere is the smallest
|
contractile unit
|
|
|
filaments that constitute myofibrils
|
myofilaments
|
|
|
3 myofilament characteristics
|
each thick filament surrounded by thin - thick + thin overlap in some areas - causes striations
|
|
|
sarcomere extends from ____ to ____
|
z-line to z-line or discs
|
|
|
z-line (band) 2 details
|
protein sheet anchors actin filaments - attaches 1 sarcomere to another
|
