Upload
wschukraft
View
1.118
Download
0
Embed Size (px)
Citation preview
Muscles
Functions of the Muscular System
• All movements of the body• Move blood through the circulatory system• Move food through the digestive system • Control the movement of air in and out of
the lungs
Types of Muscle Tissue
3 types
Cardiac Muscle
• orchestrate the sequence of cardiac muscle contraction
• Where is it found???– Only the Heart
• Involuntary
Smooth Muscle
• Close pores• Move hairs• Constricts vessels• Moves the contents of the digestive
system and circulatory system– Rhythmic contractions
• Involuntary
Skeletal Muscle
• Moves bones at the joints• Constricts cavities• Moves the skin
What is Skeletal Muscle
• Long, striated and multi-nucleated• Attaches to bone or other muscle at the
tendinous ends• between bony attachments, it crosses 1 or
more joints, moving them• muscle ALWAYS PULLS
Role of Muscle
Agonist
Moves a body segment in the intended direction – causes a movement
Antagonist
Muscle generating torque opposing that generated by the agonists, acts in the opposite direction
Examples
• Bicep Curl
• Bench Press
• Squat
• Basketball Chest pass
Muscle Contractions
3 Types
Concentric
• Muscle shortens
• Joint Moves
• Shortens through its optimal length
Eccentric
• Muscle lengthens
• “negative contraction”
• Greater increase in strength but very dangerous because of to much protein breakdown
Isometric
opposing torque at the joint is equal to the torque produced by the muscle therefore muscle length remains unchanged
No movement at the joint
Muscle actions
• Static (Isometric)– Large increase in
muscle force
– BUT –
– Specific to joint angle
• Dynamic– Concentric and
Eccentric
– Most people build muscle through both movements
Golgi Tendon Organ
• Sensory receptor that inhibits tension development in a muscle and initiates tension development in the antagonist muscles
• KEY: sense tension– stimulated by the presence of active tension
in a muscle
Golgi Tendon Organ
• Location: in the junctions between muscles and their tendons
Golgi Tendon Organ
• Action: inhibits muscle tension in the muscle generating too much force and initiates development of muscle tension in the antagonist muscle (excites)
Muscle Fiber Types
Fast twitch Vs.
Slow twitch
Type 1
• Slow twitch• Slow to contract• slow to fatigue• lowest exercise intensity• Energy source: muscle glycogen,
triglycerides, oxygen
Type 2a
• Fast to contract• Intermediate fatigue rate• Higher exercise intensity• Energy source muscle glycogen
Type 2b
• Fastest to contract• Fast fatigue rate• Highest exercise intensity• Energy source ATP-CP
FT : Fast twitch
ST: Slow twitch