Health Sciences 3300A/B Lecture 4: LEC4 NOTES

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 3300A/B
• Professor: Oleksiy Zaika

Document Summary

Hierarchical organization: sympathetic, fight or flight, stress, survival, parasympathetic, rest and digest, peaceful. Thoracolumbar output: signals that send sympathetic actions only exit through thoracic-lumbar levels of spinal cord, uses two chains that run on either side of vertebrae, output to smooth muscle of blood vessels, prepare for emergency. Parasympathetic (rest and digest: craniosacral output, parasympathetic ns also called the craniosacral system , conserve and restore energy, activity directed to gi and respiratory tracts. Somatic: synapse at ventral horn, signal goes straight to the muscle to innervate. Two-neuron system: has to have wide distribution beyond the cns, requires lots of neurons, neurons need to be placed in a location with lots of space, helps offset some weight and mess in the cns, uses some neurotransmitters. Originate from lateral gray horn (t1-l2: preganglionic axons are short, use acetylcholine, completely opposite of the way the. Parasympathetic ns works: postganglionic axons are longer, use ne/epinephrine. Travel on sympathetic chain: adjacent to vertebral column.