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)