Module 06 - The Skeletal Muscle System

Crash Course Anatomy - Muscles Part 2

Quick Review:    3 Types of Muscle are Skeletal, Cardiac, and Smooth

                            Muscle cells move when neurons send electrical signals using ionic compounds (chemicals that have a charge), which change how proteins are bound together, and cause individual cells to contract or relax, which in turn causes the entire muscle to contract or relax.

The Skeletal Muscle System

Anatomy of a muscle

Tendon - Connective tissue that attaches muscle to bone

Origin - The stationary attachment point of a muscle (the top of biceps brachii)

Insertion - The mobile attachment point of a muscle (the bottom of biceps brachii)

Belly - The “muscle” part, actually contains muscle cells and is able to contract

There are about 640 skeletal muscles

in the human body!

Muscles are named according to their size, shape, locations, orientation of fascicles, origin and insertion, number of heads (origins), and function.

Muscles can only contract, or pull, so they usually work in opposing pairs.


Muscles work with bones and joints to form levers that do the work of moving the body.

Module 6 - The Skeletal Muscle System