CSB346H1 Lecture Notes - Lecture 3: Intercostal Nerves, Intercostal Muscle, Brainstem

• School: UTSG
• Department: Cell and Systems Biology
• Course: CSB346H1
• Professor: John Peever

Document Summary

Sights responsible for breathing have been a source of speculation in western culture for 100"s of years. Galen: injured below neck continued breathing but those injured in the neck stopped breathing. breathing starts in the base of the brain (medulla) Circuits from breathing lay in brainstem or upper spinal cord. Legallois: "extracted" tissue (vagal nerve) from brainstem to determine what parts of this structure cause breathing. Ramon y cajal: how breathing rhythm was generated and modulated. Traced nerves to muscles of diaphragm, chest, lungs, spinal cords etc. Respiratory neurons -> motor neurons -> diaphragm / intercostal muscles. Adrian & buytendijk: recorded slow rhythmic oscillations in the isolated in vitro goldfish brainstem. First evidence that bs generated the signal to breath. Gesell: recorded extracellular action potential of individual neurons in the bs. First clue that breathing -> generated by neuron-neuron communication in the medulla. Respiratory rhythm generator (bs) -> respiratory motoneurons & respiratory muscles -> muscle contraction -> thoracic expansion.