Master Skeletal Muscle Contraction Initiation with Picmonic for Pre-Health

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 Initiation

Skeleton-Muscle-Man Initiating attack
The process of contracting skeletal muscle is a well-defined process initiated by nervous system impulses. The somatic motor neuron releases acetylcholine, a neurotransmitter, which activates sodium/potassium channels. Sodium rushes into the cell causing depolarization and action potential generation. The muscle reaches an all-or-nothing threshold, which is an electrical potential value that triggers the opening of voltage-gated channels. In muscles, voltage-gated calcium channels open, allowing for calcium influx. Additionally, the sarcoplasmic reticulum floods calcium into the cytosol. The flood of calcium binds to filaments of the myofibrils.
Somatic Motor Neuron Releases Acetylcholine
Sumo-tick neuron terminal firing A-seagull-cola

Somatic motor neurons are part of the voluntary nervous system. Upon nerve firing, they release acetylcholine from the nerve terminal, and the acetylcholine activates sodium/potassium channels.

Acetylcholine Causes Sodium Influx
A-Seagull-cola tipping Salt-shaker over into bucket

By activating sodium/potassium channels, acetylcholine allows for sodium influx into the cell, causing depolarization.

Cell Reaches All-or-Nothing Threshold
Scale tipping All the way

The cell reaches an all-or-nothing threshold electric potential value. This means that if the electric potential isn’t high enough nothing happens. When it is high enough, the potential is overcome, and this triggers opening of voltage-gated calcium channels.

Voltage-Gated Calcium Channels Open
Cow-cage shocked with Gate open

Voltage-gated calcium channels open on the cell membrane and allow calcium influx into the cell.

Sarcoplasmic Reticulum Causes Calcium Flood
Shark Rectangle squirting Milk-udders

The sarcoplasmic reticulum responds to the calcium influx and depolarization by releasing its internal calcium storage.

Calcium Flood Enters Myofibrils
Milk landing on Mayo-fibers

This flood of calcium released from the sarcoplasmic reticulum enters myofibrils and binds to filaments to cause contraction.

Unlock all 6 facts & definitions with Picmonic Free!


Take the Skeletal Muscle Contraction Initiation Quiz

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


It's worth every penny

Picmonic for Pre-Health Covers

100+ Videos
1000+ Facts

*Average video play time: 2-3 minutes

Search for a specific Video or category now!
Or create your own Picmonic

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

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

Ace Your Pre-Health Classes & Exams with Picmonic:

Over 870,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Pre-Health student study app.

Picmonic for Pre-Health covers information that is relevant to your entire Pre-Health education. Whether you’re studying for your classes or getting ready to conquer the MCAT, we’re here to help.

Works better than traditional Pre-Health flashcards.

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