The Muscular System
Our muscular system provides the main source of force to put our bodies into motion.
More than 40% of our body mass is composed of muscle.
Types of Muscular Tissue
There are three types of muscle tissue: 1. Skeletal Voluntary movement, attached to bones. 2. Smooth Involuntary movement, found in digestive tract, circulatory system, etc. 3. Cardiac Involuntary movement, found only in heart. Muscle Contraction
Skeletal Muscle Muscle fibers Myofibrils Filaments
Two types of filaments: - Thick: contain protein called myosin - Thin: contain protein called actin
The alternation of myosin and actin form structures called striations.
The energy for muscle contraction is supplied by ATP.
Controlling Muscle
Contraction
Our muscle contractions are controlled by our nervous system.
The nerve impulses in our brain signal and regulate the contraction.
The neuromuscular junction is the point that the skeletal muscle and neurons come in contact.
How Muscles &
Bones Interact
The muscles and bones in our body are joined by a tough connective tissue called tendons. As you move your bones, your muscles follow along.
Skeletal muscles work in opposing pairs: when one contracts, the other one relaxes.
Skeletal muscles generally remain in state of partial contraction (even when your legs are straight).
Neuromuscular Junction
Impulses from motor neutrons control the contractions of our skeletal muscles. The point of contact between a motor neuron and a muscle fiber is called a neuromuscular junction.
Acetylcholine, a biological neurotransmitter, is released by the motor neuron into the synapse. It then transmits the impulse across the synapse to the skeletal muscle cell.
The Skeletal System
The human body contains 206 bones that are organized into an a system we call the skeleton.
At birth, the human body contains around 350 tiny bones.
Major Bones & their Purposes
Clavicle - A doubly
Bibliography: Images and figures courtesy of Google Images Prentice Hall Biology Textbook Muscle System http://www.innerbody.com/image/musfov.html http://www.livescience.com/26854-muscular-system-facts-functions-diseases.html Skeletal System http://www.student.loretto.org/anatomyphys/chp42.htm http://www.livescience.com/22537-skeletal-system.html Integumentary System http://www.innerbody.com/anatomy/integumentary