Organism Physiology Paper

Organism Physiology Paper
The Physiological Evolution of the Crocodile

Mother Nature diversity in regards to the animal kingdom is amazing. Throughout the
Centuries, there have been changes to the globe and therefore to the habitat of the humans, animals, plants and all of the infinite organisms that live in our planet.
However, even though there have been changes, the living organisms also have adapted to their new environment by changing their genetic composition and acquiring new characteristics that allow these organisms to survive and to get well adapted to the prevailing environmental conditions.
One of the best adapted living organisms from the prehistoric era to the present history period are believed to be the crocodiles
They have a four-chambered heart and two ventricles, an unusual trait among existent reptiles. Like birds and mammals, crocodiles have heart valves that direct blood flow in a single direction through the heart chambers. They also have unique cog-teeth-like valves that, when interlocked, direct blood to the left aorta and away from the lungs, and then back around the body. This system may allow the animals to remain submerged for a longer period. Their peculiar circulatory system include assistance with thermoregulatory needs and prevention of pulmonary edema. Retaining carbon dioxide within the body permits an increase in the rate of gastric acid secretion and thus the efficiency of digestion, and other gastrointestinal organs such as the pancreas, spleen, small intestine, and liver also function more efficiently. When submerged, a crocodilian 's heart rate slows down to one or two beats a minute, and blood flow to the muscles is reduced. When it rises and takes a breath, its heart rate speeds up in seconds, and the muscles receive newly oxygenated
The capacity of the stomach is not very great, and so larger prey often cannot be eaten at the one sitting. An unusual feature of crocodiles is the tendency for them to retain hard, indigestible objects, such as stones, in the stomach. These "gastroliths" appear to help digestion, but they may also assist balance in water (hydroliths). The digestive enzymes in the stomach are particularly strong, and most bones and flesh are rapidly digested. On the other hand, hair and other keratinous substances (e.g. turtle shell), and chitin (e.g. insect cuticle), are broken down very slowly. Hair sometimes accumulates as “hairballs” within the stomach, and may later be regurgitated.
The bony scales along the back are the "armor", and some species are considered more heavily armored than others. These scales protect, to a large degree, the delicate inner organs from injury during fights with other crocodiles, and tooth marks in them are reasonably common. They also have a good blood supply, and are sites of heat exchange between the animal and its environment.
Today 's crocodiles and alligators are little changed from their prehistoric ancestors, a telling clue that these reptiles were (and remain) extremely well adapted to their environment.