CSD-2464 Lecture Notes - Lecture 6: Medulla Oblongata, External Intercostal Muscles, Thoracic Cavity
15 Feb 2017
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Support structure of respiratory system: vertebral column, sternum, ribs. Upper ribs join sternum at front via cartilage. Lower (floating) ribs connect to vertebrae only. Join to vertebral column at back (bony connections) Structure of thoracic cavity: encircled by bone (ribs, sternum, vertebrae, diaphragm forms floor of the thoracic cavity, pleural linkage connects lungs to rib cage and diaphragm. Pulmonary (visceral) pleura surrounds lungs to rib cage and diaphragm. Fluid holds the pleural layers together but allows sliding movement. The lungs respond to the expansion and contraction of the rib cage and. External intercostal muscles diaphragm movements: superficial to internal intercoastal muscles, connect osseous portions of ribs to each other, run downward toward sternum, contraction raises and expands rib cage: inhalation. Inhalation in quiet breathing: the medulla oblongata sends commands to the respiratory muscles, the diaphragm contracts. The thoracic cavity expands vertical downward: the external intercostals, interchondral portions of internal intercostals, contract:
