Comparative Vertebrate Anatomy Essay Example | Topics and Well Written Essays - 1500 words

Comparative Vertebrate Anatomy - Essay Example The seal's flippers are composed of living cells that needs constant blood oxygen supply. The dilemma is that the circulation of blood to the flippers will bring back ice-cold venous blood to the interior of the seals body. This dilemma is solved with the counter-current exchange system that is existent in these animals' flippers. Venae comitantes are veins that surround the limb arteries of the seals to prevent the return of cold venous blood to the body of the seal(Koeslag, 1995). Before the oxygenated blood enters the arteries of the flippers, the heat which is present that blood releases its heat through the venae comitantes to the cold venous blood. The oxygenated blood that enters the flipper arteries is cold as it circulates the flippers but when in enters the veins through the venae comitantes it is warmed near the body temperature (35C) utilizing the heat that it released before its entry in the flipper artery. Thus, the counter-current exchange mechanism of the seals' flippers prevent the alteration of the normal internal body temp of the animal which is 37C even though blood is continuously circulating to the flippers(Koeslag, 1995). Human beings also have a counter-current mechanism that is similar to that of the seals. ... The limbs of human beings are equipped with a counter-current system that maintains the normal temperature of the blood flows from the limbs during cold weather(Koeslag, 1995). Closely at the deep center of the limbs, the arteries of humans are strategically located. These arteries are also surrounded by venae comitantes or deep veins which receives the blood that circulated the limb arteries for transportation to the center of the cardiovascular system. The normal temperature of human blood is 37C so the oxygenated blood before entering the limb arteries transfers the heat to the venae comitantes making the oxygenated blood cold to about 20C. Then before entering the veins of the limbs the deoxygenate blood is warm to 37C in the venae comitantes. The temperature of the blood that is returned to the heart therefore remained unaltered that is still 37C. The process of blood circulation in the limbs in cold weather is slow to facilitate the function of the counter-current system(Koeslag, 1995). During warm weather that counter-current system of the human limbs is switched off because the circulation of blood to the limbs is increased compromising this system. The venae comitantes is not utilized instead the blood from the limb arteries return to through the subcutaneous veins. The blood circulating during hot weather is cooled with the facilitative dilation of the superficial veins and constriction of the venae comitantes(Koeslag, 1995). Question number 2: Camel or Camelus spp. are dessert animals that posses this taxonomic characteristic: Kindon Animalia, Phylum Chordata, Subphylum Vertebrata, Class Mammalia, Order