Integumentary System Physiological Phenomena: The properties and relationships and biological processes that characterize the nature and function of the SKIN and its appendages.Integumentary System: The outer covering of the body composed of the SKIN and the skin appendages, which are the HAIR, the NAILS; and the SEBACEOUS GLANDS and the SWEAT GLANDS and their ducts.Digestive System Physiological Phenomena: Properties and processes of the DIGESTIVE SYSTEM as a whole or of any of its parts.Nervous System Physiological Phenomena: Characteristic properties and processes of the NERVOUS SYSTEM as a whole or with reference to the peripheral or the CENTRAL NERVOUS SYSTEM.Dental Physiological Phenomena: Physiological processes and properties of the DENTITION.Digestive System and Oral Physiological Phenomena: Properties and processes of the DIGESTIVE SYSTEM and DENTITION as a whole or of any of its parts.Reproductive and Urinary Physiological Phenomena: Physiology of the human and animal body, male or female, in the processes and characteristics of REPRODUCTION and the URINARY TRACT.Musculoskeletal and Neural Physiological Phenomena: Properties, and processes of the MUSCULOSKELETAL SYSTEM and the NERVOUS SYSTEM or their parts.Circulatory and Respiratory Physiological Phenomena: Functional processes and properties characteristic of the BLOOD; CARDIOVASCULAR SYSTEM; and RESPIRATORY SYSTEM.Feathers: Flat keratinous structures found on the skin surface of birds. Feathers are made partly of a hollow shaft fringed with barbs. They constitute the plumage.Odontogenesis: The process of TOOTH formation. It is divided into several stages including: the dental lamina stage, the bud stage, the cap stage, and the bell stage. Odontogenesis includes the production of tooth enamel (AMELOGENESIS), dentin (DENTINOGENESIS), and dental cementum (CEMENTOGENESIS).Sports Nutritional Physiological Phenomena: Nutritional physiology related to EXERCISE or ATHLETIC PERFORMANCE.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.