smooth muscle contraction

Similarities with skeletal muscle contraction:

• include reactions of actin and myosin
• triggered by membrane impulses and an increase in intracellular
  calcium ions
• use energy from ATP

Differences in smooth muscle:

• two neurotransmitters (acetylcholine & norepinephrine) stimulates contractions in some smooth muscles and inhibits contractions in others
• hormones effects movements of smooth muscles – stimulating contractions in some cases and altering the degree of response to neurotransmitters in others

• slower to contract and to relax than skeletal muscle

• can maintain a forceful contraction longer with a given

  amount of ATP

• smooth

  muscle fibers can change length without changing tautness (example: stomach & intestines wall – can stretch as they filled while maintaining pressure inside these organs)