MUSCULAR SYSTEM Flashcards
Three basic muscle types found in the body
SKELETAL MUSCLE
SMOOTH MUSCLE
CARDIAC MUSCLE
Prefixes _____ and _____ refer to muscle
MYO; MYS
Prefix “sarco” means ______
FLESH
Most are attached by tendons to bones and the cells are multinucleate. These muscles are striated and voluntary.
SKELETAL MUSCLES
Encloses a single muscle fiber
ENDOMYSIUM
Wraps around a fascicle of muscle fibers
PERIMYSIUM
Covers the entire skeletal muscle
EPIMYSIUM
On the outside of the epimysium
FASCIA
Are cord-like structures and most collagen fibers. Often cross a joint due to toughness and small size.
TENDONS
Are sheet-like structures. Attach muscles indirectly to bones, cartilages, or connective tissue coverings.
APONEUROSES
Sites of muscle attachments
BONES
CARTILAGE
CONNECTIVE TISSUE COVERINGS
Lack striations. Spindle-shaped cells and are single nucleus. These muscles are involuntary and found mainly in the walls of hollow organs.
SMOOTH MUSCLES
Striations are present. Usually has single nucleus and are involuntary and only found in the walls of the heart.
CARDIAC MUSCLE
Are specialized plasma membrane
SARCOLEMMA
Long organelles inside muscle cells
MYOFIBRILS
Specialized smooth endoplasmic reticulum
SARCOPLASMIC RETICULUM
Light band and contains only thin filaments
I BAND
Dark band and contains the entire length of the thick filaments
A BAND
Contractile unit of muscle fiber
SACROMERE
Thick filaments
MYOSIN FILAMENTS
Thin filaments
ACTIN FILAMENTS
The zone in the A band that lacks actin filaments
H ZONE OR BARE ZONE
Stores and releases calcium. Surrounds the myofibril.
SARCOPLASMIC RETICULUM
Ability to receive and respond stimulus
EXCITABILITY (RESPONSIVENESS OR IRRITABILITY)
Ability to shorten when an adequate stimulus is received
CONTRACTILITY
Ability of muscle cells to be stretched
EXTENSIBILITY
Ability to recoil and resume resting length after stretching
ELASTICITY
Skeletal muscles are stimulated by a ____________ to contract
MOTOR NEURON (NERVE CELL)
One motor neuron and all the skeletal muscle cells stimulated by that neuron
MOTOR UNIT
Association site of axon terminal of the motor neuron and muscle
NEUROMUSCULAR JUNCTION