Medicine (MD/DO)
Fundamentals of Musculoskeletal Physiology
Skeletal Muscle Contraction Action

Master Skeletal Muscle Contraction Action with Picmonic for Medicine

With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.

Skeletal Muscle Contraction Action

Recommended Picmonics

picmonic thumbnail
Skeletal Muscle Contraction Initiation
picmonic thumbnail
Muscle Types
picmonic thumbnail
Skin Functions
picmonic thumbnail
Foot Bones

Skeletal Muscle Contraction Action

Skeleton-Muscle-Man flexing his Muscle
Skeletal muscle contraction action describes the process by which the muscle contracts, starting with calcium binding to troponin. The calcium enters the cell through the opening of voltage-gated calcium channels and binds to troponin within muscle cells. This causes an allosteric shift that moves tropomyosin and exposes the active binding site on actin. The myosin head binds to the active site and uses ATP hydrolysis (and phosphate release) to drive a conformational change, which results in myosin pulling on actin, an action also known as the power stroke. Finally, the release of ADP causes the myosin head to disengage from actin. This process results in large amounts of ATP consumption, so muscle cells must have many mitochondria producing ATP to adequately keep up with energy demand.
Calcium Binds Troponin
Cows grabbing the T-rope

An action potential in a motor neuron leads to acetylcholine release. Acetylcholine binds with receptors on the muscle fibers, opening sodium channels, with release of calcium. Calcium influx from voltage-gated calcium channels results in calcium binding to troponin on the muscle fiber.

Active Site Exposed
Revealed Action-clapperboards

The calcium binding causes an allosteric change in troponin, shifting tropomysin, which was blocking the active site. This movement exposes the binding sites on the actin filament.

Many Mitochondria Produce ATP
Mitochondria-factory Producing ATP-batteries

The power stroke of contraction requires ATP, so to keep up with muscle demands for ATP there are many mitochondria producing ATP in muscle cells.

Myosin Head Binds
Mayo-sun Head Binds to active-site

The myosin head binds to the newly available active site, initiating the power stroke. They do so by breaking down ATP to ADP and a phosphate group.

Power Stroke
Swimming Stroke

The power stroke occurs when multiple myosin molecules generate force through ATP hydrolysis, which causes a conformational shift and myosin to pull against actin.

Myosin Head Releases Active Site
Mayo-sun Head Disconnects from Action-clapper

The release of the ADP allows the myosin head to unbind from the active site on actin, until more ATP hydrolysis occurs with another power stroke.

ATP Consumed
ATP-battery Chomped Into ADP and P

Many ATP are consumed for ATP hydrolysis, which allows the power stroke and muscle contraction to occur.


Take the Skeletal Muscle Contraction Action Quiz

Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.

It's worth every penny

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Memorize facts with phonetic mnemonics

Ace Your Medicine (MD/DO) Classes & Exams with Picmonic:

Over 1,890,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Medicine (MD/DO) student study app.

Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medicine (MD/DO) education. Whether you’re studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, we’re here to help.

Works better than traditional Medicine (MD/DO) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.