Disaturates Glottis

Respiratory systems vary from species to species but the basic anatomy for Serpentes suborder is straightforward. The average Serpentes respiratory system has two external nares, two internal nares, and a nasal cavity. While Serpentes have a nose, their nose is only meant to be another pathway for respiration. They are not used to smell like a human nose is used for. Serpentes have a glottis that is a vertical slit because it is always closed. The glottis is situated right behind the tongue and has a piece of cartilage in it which creates the hissing sound that Serpentes are known for. When air is forced through the glottis, the cartilage will vibrate and that creates the hissing sound. The Serpentes can move its glottis while it is feeding …show more content…
The inner coating is called the pulmonary surfactant and it is made of a complex mixture of phospholipids, neutral lipids, and proteins. The disaturated phospholipids are the active component of the pulmonary surfactant. The disaturated phospholipids have tails that are hydrophobic and are tightly packed together which allow the reduction in surface tension. The reduction aids in inspiration and the surfactant also aids in expiration. When the gas holding structures deflate, the surfactant prevents the structures from sticking together. Since Serpentes have an air sack that gets completely collapsed when swallowing prey, the surfactant needs to be more fluid than what is commonly found in vertebrates to prevent the air sack from gluing itself together permanently. The surfactant would need to reduce the surface tension be below that of water. Therefore the surfactant for the air sack would require less of the disaturated phospholipids and have more unsaturated phospholipids or cholesterol. This explains why the secretory glands in the air sac are few and far between one …show more content…
The organs of a Serpentes need to be thin and long to allow for locomotion. Two complete lungs would limit the motion of the vertebrate, therefore disadvantageous. There are some Serpentes with complete left lungs that are seen as primitive. Usually the Serpentes with a complete left lung are also found with diminished hind legs, called spurs, that are used to help reproduce (Evolution). One example of this is the family Pythonidae, such as the Python regius. Python regius are commonly called ball pythons. The Python regius have a left lung that is 81.2% developed