Muscular System III

1
Muscular System III

• Karen Kraus
• BIOL 203
• April 12, 2007

2
Youre so smooth

• Longitudinal and circular layers
• constriction
• peristalsis
• varicosities
• diffuse junctions
• calveoli
• calcium diffusion
• gap junctions

3
Smoothies!

• Calmodulin and myosin light chain kinase
• slow
• sustained
• fatigue resistant
• smooth muscle tone

4
Smooth and in control

• Neural control
• acetylcholine
• norepinephrine
• Chemical stimulus
• hormones
• hypoxia
• hypercapnia
• acidosis

5
How many units?

• Single-unit smooth muscle
• contract as one
• gap junctions
• spontaneous contraction
• Multi-unit smooth muscle
• individual muscle contraction
• graded contractions

6
Take a load off

• Fulcrum the joint
• Effort muscle contraction applied to the
  insertion
• Load bone, along with tissues and anything else
  that is being carried

7
Working together

• Muscles only PULL
• functional groups
• prime mover (agonist)
• antagonist
• synergist
• fixator

8
When havoc strikes

• Atrophy
• Dystrophy
• Cramping and spasms