Skeletal muscle Flashcards
muscles attach via:
tendons
types of attachment to bone: and eg
origin: attach to stationary bone
insertion: attach to moveable bone
Brachii muscle originates: mid humerus, inserts into ulna over elbow
types of contraction:
isotonic: muscle changes length
- concentric (shortens)
- eccentric (lengthens)
isometric: no change in length
concentric eg:
c. contraction
picking up book
eccentric eg:
lowering book
isometric eg:
holding book steady straight arm forwards
list parts of lever system:
Lever, Fulcrum, Effort, Load
Lever:
rigid structure that moves around fixed point
Fulcrum:
fixed point lever moves around
Effort:
force which causes movement
Load:
(resistance), a force which opposes movement
general eg of lever system:
lever- bone
fulcrum- joint
effort- muscles
load- internal/ external (gym weight)
mechanical advantage:
L closer to F
E further from F
mechanical disadvantage:
L farther from F
E closer to Fulcrum
first class lever: adv/disadv? common?
Effort-Fulcrum-Load
both disadv/adv
not common
second class lever: adv/disadv? common?
Fulcrum-Load-Effort
always mechanical adv.
not common
third class lever: adv/disadv? common?
Fulcrum-Effort-Load
always mechanical disadv.
predominant due to greater range in the body
list classification of fascicles:
parallel, fusiform, circular, triangular, pennate
fascicle features: parallel
fascicles nearly parallel to long axis of muscle, flat tendons on either end
strap muscle
fascicle features: fusiform
f. nearly parallel to long axis of muscle, wide belly and tapers near ends -> tendons