Exam 5/2

• Vagus Nerve plexuses


  Ninety percent of all the preganglionic parasympathetic fibers are found in the vagus nerves
• Vagus nerves pass into the thorax


  1. Send branches through cardiac plexus

  2. Send branches through pulmonary plexus

  3. Send branches through esophageal plexus
• Cardiac plexus


  Supplies fibers to the heart that slow heart rate
• Pulmonary plexus


  Serves the airways of the lungs
• Esophageal plexus


  Serves the esophagus and part of the stomach
• The otic ganglia are not associated with vagus nerve
• Effectors of the autonomic nervous system (ANS)

  Cardiac muscle, smooth muscle, and glands
• Sympathetic nerves


  • Located in the lateral gray horns of the thoraco-lumbar
• Parasympathetic nerves


  • Located in the brain stem and the sacral region of the spinal cord
• Thyroxine (T4)


  Has two tyrosine molecules plus four bound iodine atoms
• Triiodothyronine (T3)


  Has two tyrosines with three bound iodine atoms
• Both T4 and T3 bind to thyroxine-binding globulins (TBGs) produced by the liver and bind to target receptors
• T3 is ten times more active than T4