Muscular System Flashcards
Muscle Tissues
- Skeletal
- Cardiac
- Smooth
Functions Skeletal Muscle
Responsible for moving skeleton; attached to bones or sometimes to skin
Characteristics of Skeletal Muscle
long cylindrical, striated fibers arranged parallel, under voluntary control
Excitability
Conductivity
Contractility
Extensibility
Elasticity
Excitability
ability to respond to a stimulus by changing electrical membrane potential
Conductivity
involves sending an electrical impulse down the length of the cell membrane
Contractility
Enables muscle to cause movement
Extensibility
ability to be stretched
Elasticity
ability to return to original length following a lengthening or shortening
Myofibrils
bundles of myofilaments enclosed in sarcoplasmic reticulum, makes up most of the cell’s volume; contains thick and thin filaments
Sarcoplasmic reticulum
internal membrane complex, similar to smooth endoplasmic reticulum
Terminal Cisternae
blind sacs of sarcoplasmic reticulum
Thick Filaments
consist of bundles of many myosin protein molecules; two heads and two intertwined tails; binding site for actin
Thin filaments
two twisted strands of filamentous actin (F-actin); necklace of G-actin; troponin and tropomyosin are regulatory proteins
Tropomyosin
twisted string like protein covering actin in noncontracting muscle
Troponin
globular protein attached to tropomyosin
