Somewhere between 80 to 90% of the blood ejected by the right ventricle goes through the duct into the descending thoracic aorta with minimal resistance.
The remainder of the descending thoracic aorta was also stiff and somewhat narrow, while the abdominal aorta was pliable and of normal caliber.
The resulting larva is essentially headless and also lacks the thoracic limbs characteristic of almost all insects.
Cuticular prominences as in the two previous instars occur on all the thoracic and abdominal segments except the prothorax, disposed as in the previous instar.
The cardia region spans the very anterior part of the thoracic midgut, the stomodeal valve and the oesophagus.
The horse also has a very stiff chest wall that limits the thoracic displacement to ventilation during exercise86 and mandates a proportionally greater diaphragmatic displacement.
Other persons may have discordance between the thoracic organs, which are usually arranged, and the abdominal organs, which are mirror-imaged, but no evidence of isomerism.
At the level of the sixth thoracic vertebra, a large artery supplied the left lingula and lower lobe pulmonary arteries.