Structural Adaptations within Organ Systems.
Almost all parts of animals are structured specifically to meet their function. Many examples of this are within animal organ systems, specifically the digestive and respiratory systems, where certain adaptations have allowed certain animals to improve their transport or exchange of molecules (or ions) within their body. .
The digestive system has several structural adaptations that differ between species often as a result of different diets. One of the most obvious structural adaptations can be seen within the oral cavity, specifically dentition. A direct result of different animal diets, evolution has shaped the dental structure of different animals according to the requirements of their diets. Carnivores, mainly meat eaters, generally have big incisors and canines, which are used to kill and rip pieces of prey, in addition to jagged premolars and molars, which shred and grind food. Herbivores, plant eaters, have as expected, a less destructive dental set, consisting mainly of teeth with broad, ridged surfaces, to grind food, as well as modified incisors and canines to bite off vegetation. Omnivores, meat and plant eaters, have a mix of the two extremes "humans have both blade-like incisors and canines as well as an assortment of molars to grind food. Another adaptation with the digestive system is within the overall length of the alimentary canal (the digestive tract) in different animals. Once again greatly influenced by diet, some animals such as herbivores and omnivores have longer tracts than herbivores, in general. The longer tracts equal a larger surface area which is needed for the absorption of food. The intestines are also made up of villi and microvilli which further increase surface area and absorption. This is because vegetation takes longer and is harder to digest than meat because of the presence of cell walls. For example, a koala has to chew excessively to make sure the plants go down in small pieces.
