This animation may only be used in support of a single legal proceeding and for no other purpose. Read our License Agreement for details. To license this image for other purposes, click here.
MEDICAL ANIMATION TRANSCRIPT: Skeletal muscles are voluntary, controlled consciously by the nervous system, and are made up of fascicles, which are bundles of muscle fibers surrounded by connective tissue, blood vessels, and nerves. Motor nerve axons supply one or more skeletal muscle fibers, constituting a motor unit. Inside a muscle fiber, thread-like structures called myofibrils are organized into contractile units, or sarcomeres, reflecting the striations characteristic of skeletal muscle. Each sarcomere is made up of thick and thin myofilaments, strands of proteins called myosin and actin. Myosin forms thick filaments. Actin forms thin filaments. The protruding heads of myosin filaments form cross bridges that bind to actin filaments and ATP, an energy transport molecule. Thin filaments contain a sequence of actin molecules with myosin-binding sites. At rest, actin molecules bind tropomyosin and troponin, two contractile proteins that inhibit contraction. Skeletal muscle contraction begins at the muscle fibers' plasma membrane, or sarcolemma, with invaginations called transverse or T-tubules that surround each myofibril, and open to the extracellular space. T-tubules connect to a membranous network called the sarcoplasmic reticulum that store calcium and transfer ions via voltage-gated channels into the myofibril sarcoplasm to regulate muscle contraction. In the first step of muscle contraction, called excitation, a motor nerve fires an impulse, or action potential, across the neuromuscular junction, depolarizing the sarcolemma, and generating an action potential that spreads through the sarcolemma into the T-tubules, and excites the muscle fiber. The second step is coupling, wherein the action potential depolarizes the T-tubules. Channels in the sarcoplasmic reticulum release calcium into the sarcoplasm. Along the myofilaments, troponin binds calcium and separates from tropomyosin. In the third step, called contraction, tropomyosin shifts away from actin to expose the myosin-binding sites, enabling myosin to bind to actin, resulting in the activation of ATP and the cross bridges. Released energy causes the myosin heads to rotate and pull the thin filaments inward, sliding past the thick filaments and shortening the sarcomere. The fourth step of muscle contraction is relaxation, in which calcium ions return to the sarcoplasmic reticulum and break the myosin-actin bonds. The cross bridges disengage, and the sarcomere lengthens, resulting in relaxation of the muscle and the end of the contraction. ♪ [music] ♪
"For us, the defining feature of effective demonstrative evidence is
whether, by itself, the piece will tell the story of the case. Medical legal
Art provides our firm with illustrations and animations that are clear and
persuasive. Their exhibits tell the story in a way that allows the jury to
understand a very complex subject, very quickly."
James D. Horwitz Koskoff, Koskoff & Bieder, P.C. Bridgeport, CT
"Thank you for the splendid medical-legal art work you did for us in the
case of a young girl who was blinded by a bb pellet. As a result of your
graphic illustrations of this tragic injury, we were able to persuade the
insurance company to increase their initial offer of $75,000.00 to
$475,000.00, just short of their policy limits.
We simply wanted you to know how pleased we were with your work which, to
repeat, was of superlative character, and to let you know that we would be
more than willing to serve as a reference in case you ever need one. Many
thanks for an extraordinary and dramatic depiction of a very serious injury
which clearly "catapulted" the insurance company's offer to a "full and
fair" amount to settle this case."
Philip C. Coulter Coulter &Coulter Roanoke, VA
"I just wanted to let you know that after several days on trial, I settled
[my client's] construction accident case for $4.5 million. Immediately after
the jury was discharged, I spoke with several jurors who told me that they
really appreciated the medical illustrations for their clarity in dealing
with [my client's] devastating injuries. They also expressed their gratitude
in being able to read from a distance all of the notations without
difficulty. Obviously, the boards were visually persuasive. I am certain
that this contributed to our successful result."
Michael Gunzburg, Esq.
Attorney at Law.
New York, NY
"Medical illustrations are essential evidence in personal injury litigation and MLA is simply the best I've found at producing high-quality illustrations. Your illustrators are not only first-class artists, but creative and responsive. Your turn around time is as good as it gets. My clients have won over $60 million in jury verdicts and I can't recall a case which did not include one of your exhibits. On behalf of those clients, thanks and keep up the great work!"
Medical Legal Art creates medical demonstrative evidence (medical
illustrations, drawings, pictures, graphics, charts, medical animations,
anatomical models, and interactive presentations) for use during legal
proceedings, including research, demand letters, client conferences,
depositions, arbitrations, mediations, settlement conferences, mock jury
trials and for use in the courtroom. We do not provide legal or medical
advice. If you have legal questions, you should find a lawyer with whom you
can discuss your case issues. If you have medical questions, you should seek the advice of a healthcare provider.
