The Muscular System • Found in internal organs such as stomach, bladder, walls of
arteries
Muscle Functions • Graded contractions and slow responses
• Produce body movements • Often sustain long term tone
• Stabilize body positions • Often triggered by autonomic nerves
• Regulate organ volume • Modulated chemically, by nerves, by mechanical events
• Moving substances internally (stretching)
• Producing heat
Types of muscle & function
• Skeletal
• Cardiac
• Smooth
• Skeletal- 40-50% of total body weight- voluntary
• mostly movement of bone & body parts
• Stabilizing body positions
• Guard entrances and exits
• maintains body temperature
• stores nutrients reserve
• Cardiac- only in heart- involuntary
• Heart only
• Develops pressure for arterial blood flow
Skeletal Muscle Tissue
• Muscle includes: muscle fibers, connective tissue, nerves &
blood vessels.
o Also called Striated Muscle
• Involuntary
o Contractility- ability of skeletal muscle to shorten
with force
o Excitability- is the capacity of skeletal muscle to
respond to a stimulus
• Smooth- grouped in walls of hollow organs o Extensibility- means that skeletal muscles stretch
• Sphincters regulate flow in tubes o Elasticity- the ability of skeletal muscles to recoil to
their original resting length after they have been
• Maintain diameter of tubes
stretched.
• Move material in GI tract and reproductive organs
• Well-supplied with blood vessels and nerves
• Involuntary
• Terminal of a neuron on each muscle fiber
arteries
Muscle Functions • Graded contractions and slow responses
• Produce body movements • Often sustain long term tone
• Stabilize body positions • Often triggered by autonomic nerves
• Regulate organ volume • Modulated chemically, by nerves, by mechanical events
• Moving substances internally (stretching)
• Producing heat
Types of muscle & function
• Skeletal
• Cardiac
• Smooth
• Skeletal- 40-50% of total body weight- voluntary
• mostly movement of bone & body parts
• Stabilizing body positions
• Guard entrances and exits
• maintains body temperature
• stores nutrients reserve
• Cardiac- only in heart- involuntary
• Heart only
• Develops pressure for arterial blood flow
Skeletal Muscle Tissue
• Muscle includes: muscle fibers, connective tissue, nerves &
blood vessels.
o Also called Striated Muscle
• Involuntary
o Contractility- ability of skeletal muscle to shorten
with force
o Excitability- is the capacity of skeletal muscle to
respond to a stimulus
• Smooth- grouped in walls of hollow organs o Extensibility- means that skeletal muscles stretch
• Sphincters regulate flow in tubes o Elasticity- the ability of skeletal muscles to recoil to
their original resting length after they have been
• Maintain diameter of tubes
stretched.
• Move material in GI tract and reproductive organs
• Well-supplied with blood vessels and nerves
• Involuntary
• Terminal of a neuron on each muscle fiber
