DAT Muscular System Cheat Sheet Flashcards
contain microfilaments divided
into sarcomeres
myofibril.s
individual contractile units
separated by a border
sarcomere
what is border of sarcomere called
z line
stores Ca+2 and
surrounds myofibrils
sarcoplasmic reticulum
what does sarcoplasmic reticulum store
Ca2+
same thing as cytoplasm, but for sarcomeres
sarcoplasm
plasma membrane of muscle
cells that can propagate action potentials
that are invaginated by T-tubules (channels
for ion flow)
sarcolemma
channels for ion flow
t tubules
present in large
amounts in myofibrils
mitochondira
When we use a muscle, do we contract muscle fully right away
no
motor neuron and all the
muscle fibers it stimulates
individual motor unit
The more force a muscle needs to deliver ->
the more the motor unit gets recruited
the more
motor units get recruited ->
the more fibers that are used to generate force
As submaximal stimulus increases, motor unit
recruitment..
increases
When a maximum stimulus is reached all motor units…
are recruited
Striated appearance
cardiac muscle
One or two central nuclei
cardiac muscle
Cells separated by intercalated
discs that have gap junctions
cardiac muscle
A lot of mitochondria
cardiac muscle
Lacks striation
smooth muscle
Contains one central nucleus,
smooth muscle
Stimulated by the autonomic
nervous system
smooth muscle
Does not utilize sarcomeres
smooth muscle
muscle contraction occurs occurs via the…
sliding filament model
sliding
filament model, which occurs via WHAT RESPONSE
ALL OR NOTHING
Action potential of a neuron releases…
acetylcholine
Action potential of a neuron releases
acetylcholine at a…
neuromuscular junction
An action potential is then generated
on the…
sarcolemma and throughout T-
tubules
The sarcoplasmic reticulum releases…
Ca2+
Ca2+ binds to…
troponin
Ca2+ binds to troponin on the…
actin helix
Ca2+ binds to troponin on the actin
helix, allowing WHAT TO BIND
myosin
what forms once myosin binds
Myosin cross-bridges form
what happens once the cross bridges form
contraction
occurs as depicted in
the “Sliding Filament Model”
5 main steps of sliding filament model
- Ca2+ exposes binding sites on actin:
- Myosin head attaches to actin filament:
- Inorganic phosphate is released from the myosin head:
- New ATP attaches to the myosin head à cross bridges unbind:
5.When ATP is converted to ADP + Pi, the myosin head is cocked back:
Skeletal muscles act as a
muscular pump
