Muscles Flashcards
Synergists
two (or more) muscles perform the same action
Antagonist
the muscle that is relaxing or lengthening
Agonist
Prime mover
The muscle that is contracting
Tendon
flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
aponeuroses
the tendons of flatter, broader muscles (large sheets)
Orgin
generally the point of attachment on the body that does not move when the muscle is activated
Insertion
usually the point of attachment that does move.
deep fascia
a dense connective tissue that is commonly arranged in sheets that form a stocking around the muscles and tendons beneath the superficial fascia
muscle fiber
muscle cell
myofibrils
long filaments that run parallel to each other to form muscle (myo) fibers
Parellel muscles
have fascicles that are arranged in the same direction as the long axis of the muscle
Fusiform
have a larger central region called a muscle belly tapering to tendons on each end
Convergent
has a widespread expansion over a sizable area and the fascicles come to a single, common attachment poin
Pennate
blend into a tendon that runs through the central region of the muscle for its whole length, somewhat like the quill of a feather with the muscle fascicles arranged similar to the feathers
Power lever
the effort arm is longer than the load arm,
Speed lever
the load arm is longer than the effort arm,
slow oxidative fibers
contract relatively slowly and use aerobic respiration (oxygen and glucose) to produce ATP.
fast oxidative fibers
have relatively fast contractions and primarily use aerobic respiration to generate ATP
fast glycolytic fibers
have relatively fast contractions and primarily use anaerobic glycolysis
slow oxidative function
maintaining posture, producing isometric contractions, and stabilizing bones and joints.
fast glycolytic function
produce rapid, forceful contractions associated with quick, powerful movements.
fast oxidative function
used primarily for movements, such as walking, that require more energy than postural control but less energy than an explosive movement.
glycolysis
a glucose molecule will get modified to two pyruvate molecules
krebs cycle or citric acid cycle
high-energy molecules, including ATP, NADH, and FADH2, are created. NADH and FADH2 then pass electrons through the electron transport chain in the mitochondria to generate more ATP molecules
electron transport chain
uses the NADH and FADH2 produced by the Krebs cycle to generate ATP.
Gluconeogenesis
the synthesis of new glucose molecules from pyruvate, lactate, glycerol, or the amino acids alanine or glutamine
Muscles cells consist of..
sacrolemma, mitochondria, multiple nuclei, sarcoplasmic reticulum, actin & myosin, myofibrils
myofilament
one of the individual filaments of actin or myosin that make up a myofibril
thin filament
actin, troponin, tropomyosin
thick filament
myosin
red: tendon, green: epimysium, black: perimysium, light blue: fascicle, purple: muscle fiber, yellow: sarcolemma, orange: myofibril, pink: deep fascia, blue: endomysium
At what relative length of a muscle can you produce the greatest amount of tension
(isometric contraction)
when thick and thin filaments overlap between about 80 percent to 120 percent
What is the relationship between number of crossbridges (or crossbridge cycles) formed
and the amount of tension a muscle cell can generate at a given time?
The more crossbridges, the more contractions, therefore more tension.
How does your body vary force production in a fiber?
the amount of motor units activated
What is a muscle fiber twitch?
The contraction generated by a single action potential
twitch graph
what effect
does pennation have on a muscle’s force potential?
it can produce relatively more tension for its size, compared to non-pennate muscles.
how do we produce atp at rest?
substrate: fatty acids, method: aerobic metabolism
how to we produce atp during moderate activity?
substrate: fatty acids and glucose, method: aerobic metabolism
how do we producte atp during vigorous activity?
substrate: glucose, Method: anaerobic & aerobic metabolism
what causes muscle fatigue
shortage of atp, depletion of reserves, damage to sarcolemma & SR, unable to release CA2+, lowered pH, muscle exhaustion, mental exhaustion
