ANATOMY
Unit 4 Notes:
Muscle Parts
(1) Types of Muscle
•Skeletal
•Cardiac
•Smooth
Cardiac Muscle
Skeletal Muscle
Smooth Muscle
(2) Skeletal Muscle
• Type of Movement:
– Voluntary
– Allows overall body mobility
– Contracts fast w/great force, tires fast also
• Location:
– On top of bones & connecting them
(3) Cardiac Muscle
• Types of Movement:
– Involuntary
– Steady, consistent movement
– Heartbeat (rate gauged by nervous system)
• Location:
– Heart
(4) Smooth Muscle
• Type of Movement:
– Involuntary
– Slower, yet consistent movement
– Forces fluids & solids through channels
• Location:
– Digestive & excretive organs
– Respiratory passageways
(5) Muscle Function
• Produce movement
– Bones = attachment points
– Internal organs (move nutrients, waste, etc.)
• Maintain posture
– Unique to Bipedalism
• Stabilize joints
– Allows for wider range of movement and use of force
• Generate heat
– During contraction
(6) Levels of Organization
• Muscle (whole organ)
• Fascicle (portion of muscle)
• Muscle Fiber (single muscle cell)
• Myofibril (muscle cell organelle)
• Sarcomere (portion of myofibril)
• Myofilaments—Actin + Myosin
(part of sarcomere)
Macroscopic
Microscopic
Muscle (organ)Fascicle
Muscle Fiber (cell)
Muscle Fiber
(with many nuclei)
Myofibril
Sarcomere
Thin Filament (actin)
Thick Filament (myosin)