BIOS 252 Week 1 Study Guide
How is skeletal muscle identified?
Long, thin, cylindrical in shape, multinucleated, striated, attached via tendons to bones
Where is muscle in the skeleton? Attached to bones and skin of the skeleton
What control is skeletal muscle under?
Voluntary
What is the function of skeletal muscle?
Moves bones as well as the skin of the face
How is cardiac muscle identified?
Short, fat, branched, uninucleated, striated, attached to intercalated discs
Where is cardiac muscle located?
Only found in the heart What control is cardiac muscle under?
Involuntary
What is the function of cardiac muscle?
Pump blood from the heart into the blood vessels
How is smooth muscle identified?
Gap junctions connect the intermediate filaments, which are uninucleated and lack obvious
striations. Where is smooth muscle located?
Various organs of the body (mostly "hollow" organs or organs that have an opening in the
center through which other substances travel)
What kind of control does smooth muscle have? Involuntary
What is the function of smooth muscle?
Move substances withing the tube (ex: peristalsis)
What is a sarcomere?
Contractile unit from one z-disc to another z-disc
What is the sarcolemma?
The plasma membrane of a muscle cell
What is the sarcoplasmic reticulum?
Stores calcium for the cell
What is the Z disc (line)?
Provides the anchorage for the actin and titin filaments
What is the M-line?
The line found at the center of the thick filament. Provides an anchor for the thick filament
What is the A-band?
From the beginning of one thick filament to the end of the same thick filament. This is what
creates the dark band
What is the I-band?
From the end of one thick filament to the beginning of the next thick filament. This is what
creates the light band
What is the zone of overlap?
Where thick and thin filaments overlap
What is the thick filament (myosin)?
The myosin will join to the actin and create the contraction of a muscle fiber
, What exactly is actin's thin filament? Actin has an active spot that lets it bind to myosin to
make the skeletal muscle fiber contract and shorten. What are contractile proteins?
Actin and myosin
What are structural proteins?
tropomyosin and troponin What are regulatory proteins?
Troponin and tropomyosin
What is the organization of a skeletal muscle (smallest to largest)?
Microfilaments, myofibril, muscle fiber, muscle fascicle, and skeletal muscle
What are the connective tissues of skeletal muscle?
Endomysium, perimysium, and epimysium
What is the endomysium?
Seperate individual muscle fibers from one another
What is the perimysium?
Surrounding 10 to 100 muscle fibers seperating them into bundles called fascicles
What is the epimysium?
Outer layer encircling the entire muscle
What does the sliding filament theory always start with?
A motor nerve
What are the sliding filament theory's steps 1 through 6? Excitation-contraction coupling
What is the 1 step of the sliding filament theory?
Synaptic vesicles will reach the membrane of the synapse and release ACh into the
synaptic cleft
What is the 2 step of the sliding filament theory?
ACh binds to ACh receptor proteins present on the ligand-gated channels
What is the 3 step of the sliding filament theory?
ACh receptor proteins will open/allow influx of Na+ ions into muscle fiber
What is the 4 step of the sliding filament theory?
Muscle fiber depolarizes/generates an action potential
What is the 5 step of the sliding filament theory?
Action potential travels down tubules and pass by sarcoplasmic reticulum
What is the 6 step of the sliding filament theory?
Voltage-gated calcium channels open up; SR releases Ca2+ into the cystol of the cell
What is the 7 step of the sliding filament theory?
Ca2+ attached to regulatory proteins and move them from the binding spots
What is the 8 step of the sliding filament theory?
ATP is hydrolyzed by myosin ATPase and turned into ADP and a phosphate
What is the 9 step of the sliding filament theory?
Cocked myosin head binds to actin making a cross-bridge between actin/myosin
What are steps 10-13 of the sliding filament theory?
Mechanism of Contraction
What is the 10 step of the sliding filament theory?
"Power Stroke"
What is the 11 step of the sliding filament theory?
Actin moves down myosin filament
What is the 12 step of the sliding filament theory?
If Ca2+ remains, #7-#10 steps repeat
What is the 13 step of the sliding filament theory?
Relaxation
How is skeletal muscle identified?
Long, thin, cylindrical in shape, multinucleated, striated, attached via tendons to bones
Where is muscle in the skeleton? Attached to bones and skin of the skeleton
What control is skeletal muscle under?
Voluntary
What is the function of skeletal muscle?
Moves bones as well as the skin of the face
How is cardiac muscle identified?
Short, fat, branched, uninucleated, striated, attached to intercalated discs
Where is cardiac muscle located?
Only found in the heart What control is cardiac muscle under?
Involuntary
What is the function of cardiac muscle?
Pump blood from the heart into the blood vessels
How is smooth muscle identified?
Gap junctions connect the intermediate filaments, which are uninucleated and lack obvious
striations. Where is smooth muscle located?
Various organs of the body (mostly "hollow" organs or organs that have an opening in the
center through which other substances travel)
What kind of control does smooth muscle have? Involuntary
What is the function of smooth muscle?
Move substances withing the tube (ex: peristalsis)
What is a sarcomere?
Contractile unit from one z-disc to another z-disc
What is the sarcolemma?
The plasma membrane of a muscle cell
What is the sarcoplasmic reticulum?
Stores calcium for the cell
What is the Z disc (line)?
Provides the anchorage for the actin and titin filaments
What is the M-line?
The line found at the center of the thick filament. Provides an anchor for the thick filament
What is the A-band?
From the beginning of one thick filament to the end of the same thick filament. This is what
creates the dark band
What is the I-band?
From the end of one thick filament to the beginning of the next thick filament. This is what
creates the light band
What is the zone of overlap?
Where thick and thin filaments overlap
What is the thick filament (myosin)?
The myosin will join to the actin and create the contraction of a muscle fiber
, What exactly is actin's thin filament? Actin has an active spot that lets it bind to myosin to
make the skeletal muscle fiber contract and shorten. What are contractile proteins?
Actin and myosin
What are structural proteins?
tropomyosin and troponin What are regulatory proteins?
Troponin and tropomyosin
What is the organization of a skeletal muscle (smallest to largest)?
Microfilaments, myofibril, muscle fiber, muscle fascicle, and skeletal muscle
What are the connective tissues of skeletal muscle?
Endomysium, perimysium, and epimysium
What is the endomysium?
Seperate individual muscle fibers from one another
What is the perimysium?
Surrounding 10 to 100 muscle fibers seperating them into bundles called fascicles
What is the epimysium?
Outer layer encircling the entire muscle
What does the sliding filament theory always start with?
A motor nerve
What are the sliding filament theory's steps 1 through 6? Excitation-contraction coupling
What is the 1 step of the sliding filament theory?
Synaptic vesicles will reach the membrane of the synapse and release ACh into the
synaptic cleft
What is the 2 step of the sliding filament theory?
ACh binds to ACh receptor proteins present on the ligand-gated channels
What is the 3 step of the sliding filament theory?
ACh receptor proteins will open/allow influx of Na+ ions into muscle fiber
What is the 4 step of the sliding filament theory?
Muscle fiber depolarizes/generates an action potential
What is the 5 step of the sliding filament theory?
Action potential travels down tubules and pass by sarcoplasmic reticulum
What is the 6 step of the sliding filament theory?
Voltage-gated calcium channels open up; SR releases Ca2+ into the cystol of the cell
What is the 7 step of the sliding filament theory?
Ca2+ attached to regulatory proteins and move them from the binding spots
What is the 8 step of the sliding filament theory?
ATP is hydrolyzed by myosin ATPase and turned into ADP and a phosphate
What is the 9 step of the sliding filament theory?
Cocked myosin head binds to actin making a cross-bridge between actin/myosin
What are steps 10-13 of the sliding filament theory?
Mechanism of Contraction
What is the 10 step of the sliding filament theory?
"Power Stroke"
What is the 11 step of the sliding filament theory?
Actin moves down myosin filament
What is the 12 step of the sliding filament theory?
If Ca2+ remains, #7-#10 steps repeat
What is the 13 step of the sliding filament theory?
Relaxation
