Quantcast
Follow us On YouTube Follow us On FaceBook



or
Search Language
Browse
Medical Animations
Medical Animation Titles
Custom Legal Animations
Patient Health Articles
Custom Interactive
Most Recent Uploads
Body Systems/Regions
Anatomy & Physiology
Diseases & Conditions
Diagnostics & Surgery
Cells & Tissues
Cardiovascular System
Digestive System
Integumentary System
Nervous System
Reproductive System
Respiratory System
Back and Spine
Foot and Ankle
Head and Neck
Hip
Knee
Shoulder
Thorax
Medical Specialties
Cancer
Cardiology
Dentistry
Editorial
Neurology/Neurosurgery
Ob/Gyn
Orthopedics
Pediatrics
Account
Administrator Login
Muscle Contraction - Medical Animation
 
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 animation for other purposes, click here.

If animation does not play, download and install the latest free Flash Player plugin.
More Like ThisAdd To Lightbox ANM11013 Enlarge Share
Ready to Purchase?

$999.00

Order by phone: (800) 338-5954
Item #ANM11013Source #1

Muscle Contraction - Medical Animation
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] ♪

YOU MAY ALSO WANT TO REVIEW THESE ITEMS:
Coronary Artery Stenosis with Placement of Multiple Stents
Coronary Artery Stenosis with Placement of Multiple Stents - exh61553c
Medical Exhibit
Add to my lightbox
Find More Like This
Muscle Contraction and Relaxation
Muscle Contraction and Relaxation - ANS00258
Medical Animation
Add to my lightbox
Find More Like This
Actin and Myosin
Actin and Myosin - 3DSC13303a
Medical Illustration
Add to my lightbox
Find More Like This
Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS) - ANH12073
Medical Animation
Add to my lightbox
Find More Like This
Uterine Contractions
Uterine Contractions - exh60195b
Medical Exhibit
Add to my lightbox
Find More Like This
Gastroparesis
Gastroparesis - exh82367b
Medical Exhibit
Add to my lightbox
Find More Like This
What attorneys say about MLA and The Doe Report:
"Thanks, and your illustrations were effective in a $3 million dollar verdict last Friday."

Joseph M. Prodor
Trial Lawyer
White Rock, British Columbia
"I have found that the personalized medical illustrations prepared by Medical Legal Art have been very accurate and helpful. The medical doctors, both treating physicians and expert witnesses, have commented on the accuracy and professionalism of the medical illustrations. Most importantly, your prompt service and attention upon even short notice has been tremendous. I can certainly say that the medical illustrations prepared by Medical Legal Art have assisted us in bringing cases to a successful resolution."

Paul L. Redfearn
The Redfearn Law Firm, P.C.
Kansas City, MO

"Medical Legal Art has always performed quality and efficient work. The doctors that review the exhibits are always amazed at the precise descriptions and drawings."

Michael Beckman
Viles Law Firm, P.A.
Fort Meyers, FL

"I wanted to thank you for the terrific job you did illustrating my client's injuries. The case was settled at the pre-suit mediation, and I believe a good part of the success we had was due to the medical legal art you prepared.

Your work received the ultimate compliment at the conclusion of the mediation. The hospital risk manager took the exhibit with them at the conclusion of mediation, and will be using it to train nurses on how to prevent bed sores..."

Steven G. Koeppel
Troy, Yeslow & Koeppel, P.A.
Fort Myers, FL













Awards | Resources | Articles | Become an Affiliate | Free Medical Images | Pregnancy Videos
Credits | Jobs | Help | Medical Legal Blog | Find a Lawyer | Hospital Marketing