Development of Internal Structures in Pinnipedia

Description

Anatomy is the study of the structure of organisms and their parts. Anatomy is a natural science field that investigates the internal structure of living things. It is an old science that began in the early back to ancient times. Anatomy is intimately connected to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes which generate anatomy on both short and long timescales. Anatomy and physiology are closely related disciplines that study the structure and function of organisms and their parts.

Pinnipeds, also known as seals, are a diverse clade of carnivorous, fin-footed, semi-aquatic, mostly marine mammals. The extant families are Odobenidae, Otariidae, and Phocidae. Pinnipeds have 34 extant species and more than 50 extinct species have been described from fossils. Blubber is the main area of fat on marine mammals and is crucial for storing energy. It also serves a number of other purposes. Seals' limbs are shorter than those of most other mammals. True seals have more developed hind flippers, while eared seals have more developed fore flippers. Both above and below the water; a seal's eyes are well suited for vision. When diving, the seal's eyes are protected by a clear membrane, its nostrils encloses automatically. To maintain the seal's streamlined shape, the testicles and mammary glands are located in slits beneath the skin. Seals have hairs to aid navigation, as well as sensors in their skull that absorb underground sounds and transmit them to the cortex web of skin connects a seal's fingers and toes. Seals have claws on either their front flippers or their back flippers. Because water is much denser than air, their wings can be significantly smaller in proportion to their size. Besides that, seals are mainly weightless in water, allowing them to come to a halt and perform aquatics in the water that atmospheric flying creatures would find impossible. Underwater, seals can save oxygen for extended periods of time. When the seal begins to dive, its heart rate slows to one-tenth of its normal rate.

The arteries constrict, and only the sensory receptors and central nervous continue to receive normal blood circulation. Seals can survive more pain and fatigue induced by lactic acid blockage than other mammals. However, once they reach the water's surface, they require time to recover and restore their body chemistry to normal. The most varied and ubiquitous of the pinnipeds are the earless seals, sometimes known as "genuine seals" or "phocids." They are more aquatically adapted and have streamlined snouts and no external ears. Earless seals have highly developed rear flippers, which they use to swim with effective undulating full body movements. They are more suited for deep and prolonged diving as well as lengthy migrations due to the effectiveness of their swimming and a variety of other physiological adaptations. Although they move by twitching their front flippers and abdominal muscles, Earless seals are quite slow on land. Hence, in contrast to verbal communication; true seals typically slap the water or its own body with a pectoral flipper.