Anatomy - Unit 5: Muscular System

Smooth Muscle

Lines hollow organs, nonstriated, involuntary

Cardiac muscle

lines heart, striated, involuntary

Skeletal muscle

voluntary, stiated, multinucleated

Excitability

can receive and respond to stimuli

contractility

can shorten forcibly

Extensibility

can be stretched or extended

Elasticity

recoils and resume resting after being stretched

Muscle

muscle cells + blood vessels + nerve fibers; surrounded by epimysium

Fassicle

bundle of muscle cells; surrounded by perimysium

Muscle Fiber

bundle of myofibrils; surrounded by endomysium

Myofibril

complex organelle housing many contractile units

Sacromere

contractile unit

Epimysium

surrounds the muscle; directly under outermost layer of fascia

Perimysium

surrounds the fascicle

Endomysium

surrounds each muscle cell

Myoblasts

mononucleated cells for skeletal muscle

Sacolemma

cell membrane of muscle fiber

sarcoplasm

cytoplasm of muscle fiber

Sarcoplasmic reticulum

tubules in muscle fiber that controls contraction

Actin
(Thin Filament)

protein for thin filament

Myosin

(Thick Filament)

protein for thick filament

I Band (Light band)

from z line to start of overlap

A Band (Dark Band)

zone of overlap to zone of overlap (Includes the zones of overlap)

H Band

thick filament and m line only

Z line

marks for ends of sacromere

cross bridges

when myosin heads bind to the actin filaments for muscle contraction

sliding filament theory

the actin and myosin slide past one another, shortening the sarcomere

motor unit

neuromuscular junction

Acetylcholine

Action potential

troponin

tropomyosin

Calcium ions

Creatine Phosphate

Aerobic Respiration

Lactic Acid Fermentation