Muscular System Flashcards
which kind of muscles have to have nerves to contract
skeletal muscles
which cell has the stimulus
each cell needs its own stimulus
what is each cell covered by?
connective tissue
what is the aponeuroses
a band of fasica, found on flat muscle. ex: epicranius
what is a tendon
its an extension of fascia, attaching bone to muscle
what is a epimysium
its located under the fascia and it covers the muscle but doesn’t extend past the muscle
what is the perimysium
covers each individual cell
where is the endomysium found
the surface of every cell
what is a fascicle made of and what is it covered by
it is made of muscle cells and covered by the perimysium
which is larger; a filament or a myofibril
myofibril
how many myofibrils is one cell made of
thousands
what is a sacrolemma
a term for cell membrane of a skeletal cell
whats the smallest unit of contraction
sacromere
does each cell have one nucleus
each cell has more than one nucleus
what is a striation
characteristic of skeletal and cardiac muscles; it is an arrangement of filaments
what is a fascicle
a collection of cells
what is a sarcomere
area of one z-line to the next
what happens when a muscle contracts
the z line moves towards each other; meaning the I band disappears
what does the A band consist of
only myosin
whats the I ban consist of
only actin
whats one thing that has to happen for a muscle to contract
the myosin has to bind to actin
what is a protein complex
two proteins working together
where are the binding sites located
on the actin
what does a triad consist of
transverse tubule, terminal cisternae, and sacromere
what’s the purpose of the sarcoplasmic reticulum?
envelop the myofibrils
what is the terminal cisternae
where calcium is stored
what do the transverse tubules connect to
the cell membrane
what is a motor unit
a motor nerve and all the individual cells it controls
what is a neuromuscular junction
place where a nerve communicates with a muscle
what type of muscle has to have a message in order to contract
skeletal muscle
what is acetylcholine
its a type of neurotransmitter, that eventually gets wiped out by an enzyme
what is acetylcholinesterase
the enzyme that removes acetylcholine
what is the motor end plate
the only place where sodium ligand-gated channels are; the only place where the nerve can talk to the muscle
with the sliding filament model, do myofibrils change in length or do the filaments change in length
the myofibrils change in length; the z lines come closer, therefore each sarcomere becomes shorter
why are the orientation of the heads on the myosin important
its important because of the way the heads are determine which direction it pulls; facing to the left then they are pulling to the right
what happens when you reach the axon terminal
the voltage gated ion channels open
what does calcium bind to
troponin
what happens after the calcium binds to the troponin
it causes troponin and tropomyosin shift and exposes the binding sites, then the myosin can attach to the actin
why does calcium exit the cell in the transverse tubule?
because of the gradient
whats the purpose of the transverse tubule
to carry impulse deep into interior
