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;
23 Cards in this Set
- Front
- Back
Motor Unit ( = Motor neuron + fibers it innervates) |
Basic functional unit of neuromuscular system
|
|
Epimysium |
Covers the body's 430+ skeletal muscles |
|
Tendons |
Attach muscles to bone |
|
Bone periosteum |
Aspect of bone to which tendons attach |
|
Fasciculi |
Groups of muscle fibers (up to 150) |
|
Perimysium |
Covers fasciculi
|
|
Endomysium |
Covers each muscle cell |
|
Sarcomere |
Smallest contractile unit of skeletal muscle |
|
T-Tubules |
Perpendicular with sarcoplasmic reticulum, and is continuous with sarcolemma(covering the cell); allowing action potential(electrical nerve impulse) to arrive simultaneously throughout |
|
Sliding-filament Theory |
Actin filaments (outer) slide in on Myosin filaments -> pulls Z-line to center of sarcomere -> muscle shortens |
|
Acetylcholine |
Neurotransmitter released by Action Potential, resulting in muscle excitement |
|
Type I Fiber |
Slow Twitch (develops force and relaxes slowly) |
|
Type IIa / IIb Fibers |
Fast Twitch (develop force and relax rapidly) |
|
Recruitment |
Process which varies number of Motor Units activated in order to increase force production |
|
Actin |
Thin Myofilament, arranged outside of Myosin sections in a double-helix structure
|
|
Myosin |
Thick Myofilament, arranged in lines between sections of Actin. Cross-bridges from this myofilament allow the two to touch |
|
Golgi Tendon Organ (GTO's)
|
Activate when muscle is placed under tension and mitigate excessive force by causing muscle to relax
|
|
Sarcopenia |
Reduction in muscle size and strength due to inactivity and aging |
|
A-band |
Corresponds with the alignment of Myosin filaments (dark in color) |
|
I-band |
Corresponds with the areas in two adjacent sarcomeres that contain only Actin filaments (light in color) |
|
Z-line |
In middle of I-band and appears as a thin, dark line running longitudinally through the I-band |
|
H-zone |
Area in center of sarcomere where only Myosin filaments are present. During contraction, it decreases as Actin slides over Myosin |
|
SA Node |
Normally initiates the heart's electrical impulse |