Muscular-skeletal system physiology

How do our muscles work? When we decide to kick a ball or shake a leg, how do we get our bodies to do that? Which muscles do we control? Which muscles control us? Learn how our muscles work at the smallest, most cellular level. Then see how nature scales up those microscopic processes into a kick or a dance move. Finally, learn how our brain tells muscle to contract and how that helps us respond to changes in temperature or even a lion chasing us.

Muscular system

Myosin and actin
How myosin and actin interact to produce mechanical force.
How tropomyosin and troponin regulate muscle contraction
How calcium ion concentration dictates whether a muscle contracts or not.
Role of the sarcoplasmic reticulum in muscle cells
The role of the sarcoplasmic reticulum in controlling calcium ion concentrations within the muscle cell.
Anatomy of a muscle cell
Understanding the structure of a muscle cell. By Raja Narayan.
Three types of muscle
Understanding the structure of a muscle cell.
Motor neurons
How do neurons help us move? Learn about how motor neurons send signals to muscle cells and what happens when we damage this precious neurons. By Raja Narayan.
Neuromuscular junction, motor end-plate
How do neurons talk directly to muscle cells? Learn about how a neuronal message is translated into a muscular action at the neuromuscular junction. By Raja Narayan.
Type 1 and type 2 muscle fibers
What's the difference between type 1 and type 2 muscle fibers? Learn one golden rule that will help you easily distinguish between them. By Raja Narayan.
Calcium puts myosin to work
See exactly how Calcium binds Troponin-C and allows Myosin to do some work.
Muscle innervation
Which muscles do we voluntarily control? Which muscles do we have NO control over? What's the difference between sympathetic and parasympathetic innervation? Learn about how our brain splits its control over the body into autonomic and somatic nervous systems.  By Raja Narayan.
Autonomic vs somatic nervous system
Understand the different divisions of the brain that control our muscles.  By Raja Narayan.
Thermoregulation by muscles
Why do we shiver when it's cold? How do our muscles make sure we don't freeze or have a heat stroke? Learn how the skin, brain, blood vessels, and muscles work together to maintain our core body temperature.  By Raja Narayan.