quiz 4 Flashcards
the outermost layer of connective tissue of a muscle is the ____?
fascicle
the thick myofibril filament of a sarcomere is composed of the protein ___?
actin
the muscle primarily responsible for an action is the ____?
agonist
the neuron and the muscle fibers it innervates make up the ___?
muscle fiber
the functional contractile unit of a muscle fiber is the _____?
sarcoplasmic reticulum
the action of a particular muscle is always the same
t/f
true
a synergistic muscle contraction assists the agonist
t/f
false
the plasma membrane of a muscle fiber is called the sarcolemma
t/f
true
protein that comprises part of the thin filament with actin
troponin
cytoplasm of a muscle fiber
sacroplasm
connective tissue located between adjacent muscles
fascia
layer of connective tissue that separates a muscle into small bundle called fascicle
perimysium
plasma membrane of a muscle fiber
sacrolemma
layer of connective tissue that surrounds a skeletal muscle
epimysium
unit of alternating light and dark striations between Z discs
sacromere
layer of connective tissue that surrounds an individual muscle fiber
endomysium
cellular organelle in muscle fiber corresponding to the endoplasmic reticulum
sarcoplasmic reticulum
cordlike part that attaches a muscle to a bone
tendon
protein found within thick filament
myosin
small bundle of muscle fibers within a muscle
fascicle
the ____ of a muscle is attached to a more fixed location
origin
the ______ of a muscle is attached to a more movable location
insertion
a muscle responsible for most of an action is called an
against (prime mover)
assisting muscles of an agonist are called
synergists
antagonists are muscles that resist the actions of ____ and cause movement in the opposite direction
prime movers
when the forearm is extended at the elbow joint, the ______ muscle acts as the agonist
triceps brachii
when the brachialis acts as the agonist, the ___ muscle assists as a synergist
antagonist
a _______ is a synergistic muscle that will stabilize a joint when another contracting muscle exerts a force on something else
fixator
electrical activity of muscles and the action potential propagated along the sacrolemma
EMG electrodes
when there is demand to stimulate more motor units within a muscle to help it contract as a load increases
motor unit recruitment
a recording of skin-surface voltage that is produced by underlying skeletal muscle contractions
electromyography
