Thursday, October 13, 2016

ch. 6 | the muscular system

  • skeletal muscle tissue is attached to the bones
-striated, voluntary
-produces body movements
-stabilizes the skeleton
-produces heat/maintains body temperature
  • cardiac muscle tissue is found only in the heart
-striated, intercalated discs, involuntary 
-makes up walls of heart
-generates force to pump blood
  • smooth muscle tissue is found in most body organs
-not striated, involuntary 
-forms walls of hollow organs 
-stores and moves substances w/in body
-regulates organ volume
  • sarcomere: contractile unit/building block of a muscle fiber 
  • plasma membrane--> sarcolemma 
  • cytoplasm--> sarcoplasm
  • endoplasmic reticulum--> sarcoplasmic reticulum: transport system 
  • myosin makes up thick filaments 
  • actin makes up thin filaments 
  • nerve signals initiate the contraction of skeletal muscle
  • muscle & nerves DO NOT touch, they meet at a neuromuscular junction: synapse btwn the axon terminals of a motor neuron & the sarcolemma of a muscle fiber 
  • peristalsis: wave-like contraction of muscles 
  • muscles can only contract- not extend
sources that provide ATP:
  1. creatine-phosphate: transfers phosphate from ADP to make ATP
  2. anaerobic respiration (glycolysis): does not require oxygen
  3. aerobic respiration: requires oxygen from myoglobin; provides more ATP than the others 
skeletal muscles work in groups:
  • origin: where a muscle attaches to a stationary bone
  • insertion: other end of muscle is attached to movable bone 
  • belly: fleshy portion of the muscle

skeletal muscles of the body:

-masseter: elevates mandible (closing mouth)
-rectus abdominis: compresses abdomen to aid in defecation, urination, forced exhalation, childbirth
-internal & external oblique: compresses abdomen, bends vertebral column laterally & rotates it 
-transverse abdominis: compresses abdomen

-diaphragm: contracts to inhale & exhale 

No comments:

Post a Comment