The Muscular System
By: Anthony Martinez
The Function of The Muscular System
The function of the Muscular System is to provide support for human movement, to create proper posture and to circulate blood.
Smooth Muscular Tissue
Smooth muscle fibers are located in walls of hollow visceral organs and are under involuntary control.
Skeletal Tissue
Skeletal muscle fibers are in muscles which are attached to the skeleton and are under voluntary control.
Cardiac Muscle Tissue
Cardiac Muscles are located in the walls of the heart and are under involuntary control.
A Diagram of A Sarcomere
How Skeletal Muscles Contracts
When muscles contract, actin moves the myosin over and causes the sarcomere to shorten actin fibers are thin and myosin fibers are thick
arriving action potential causes Ca2+ to be released from endoplasmic reticulum Ca2+ binds to troponin which causing troponin and tropomyosin to move this exposes binding sites on actin for myosin. ATP binds to myosin heads which releases them and breaks cross bridges, ATP hydrolyzed and the energy causes myosin heads to change shape.
Two Disorders In The Muscle System

Muscular Dystrophy
Symptoms: Symptoms of Muscular Dystrophy are Frequent falls, difficulty getting up from a lying or sitting position, trouble running and jumping, waddling gait, walking on the toes, large calf muscles, muscle pain and stiffness, and learning disabilities.
Prevalence: About 1 out of every 7,000 males suffer from Muscular Dystrophy.
Treatment: There is no cure for Muscular Dystrophy, but physical therapy can control the symptoms.
Myopathy
Symptoms: The symptoms of Myopathy are aching, cramping, pain, stiffness, tenderness, and tightness.
Prevalence: 1 in 3330 of boys suffer from Myopathy.
Treatment: The treatment for Myopathy is therapy and bracing to support the muscles.