PSL301H1 Lecture Notes - Lecture 19: Accessory Muscle, Alanine, Breathing
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PSL301H1 Full Course Notes
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Document Summary
Case study: boy with ondine"s curse (congenital central hypoventilation. During the day breathes on own, but anytime he falls asleep he must be attached to a ventilator (has a trachea tube). Rhythmic breathing (medulla and pons) can be influenced by: Voluntary control (speech) from the motor cortex. Posture affects the intercostal and abdominal muscles. All of these involve the central nervous system. What is the common pathway for all systems attempting to control the respiratory muscles. Phrenic motoneurons whose axons make up the phrenic nerve, which drives the diaphragm, are found in cervical spinal chord segment, c3, c4, and c5. The motoneurons for the intercostal nerve, which drive the intercostal muscles are found in the thoracic spinal segments t1 and t2. Relationships between tidal volume and phrenic nerve activity. Phrenic nerve is active during inspiration and not active relatively during expiration. Rhythmic activity of respiratory motor neurons mainly controlled by pre-motor neurons in the medulla.
