ch9 - muscular system Flashcards
(20 cards)
endomysium
loose connective tissue that surrounds each muscle fiber
provides chemical environment for the exchange of ions for nervous stimulation
fasicle
bundle of muscle fibers covered by a connective tissue sheath
perimysium
connective tissue covering the fasicles
epimysium
all the fascicle’s together form the entire muscle
sarcolemma
muscle cell membrane
sarcoplasm
cytoplasm of the muscle fiber
microfibrils
long parallel structures beneath the sarcoplasm
has two types of filaments
thick composed of myosin
thin composed of actin
sarcomere
units within each fiber - myofibrils are sarcomeres joined end to end
synapse
where each cell that a neuron controls is attached to the end of an axon
neurotransmitters
chemicals used by neurons to communicate with cells
motor neurons
neurons that control effectors, including skeletal muscle fibers
motor end plate
muscle fiber membrane specialized form, where nuclei and mitochondria are abundant and the sarcolemma is intensively folded
synaptic clef
small gap that separates the membrane of the neuron and the membrane of the muscle fiber
Acetylcholine (Ach)
neurotransmitter that motor neurons use to control skeletal muscle contraction.
muscle contraction
action potential
motor neuron releases ach
ach binds to ach receptors
motor end plate stimulated, action potential generated to adjacent are, impulse conducted
calcium ions diffuse bind to troponin
tropomyosin molecules expose sites on actin where myosin heads can bind
cross bridges form linking filaments
thin filaments pulled toward center of sarcomere overlapping with thick
ATP
myosin enzyme
latent period
threshold stimulus
level of stimuli required for a muscle fiber to respond
Origin
less movable end of a skeletal muscle
insertion
more movable end of a skeletal muslce
