Respiratory System
14Respiratory System Introduction As animals evolved from single‐celled organisms to multilayered organisms, it became impossible for oxygen to diffuse effectively to all cells. Consequently, systems evolved to deliver oxygen and…
Digestive System
17Digestive System Digestive System Overview All animals need a supply of nutrients and oxygen that are obtained via the digestive system and respiratory system, respectively. The digestive system consists of…
Endocrine System
12Endocrine System Introduction and Overview The nervous system, with its sensors and capacity for rapid response, combined with often longer‐term impacts of the endocrine system is critical for the maintenance…
Bones and Skeletal System
6Bones and Skeletal System Bones Introduction Osteology is the study of bones. The skeleton provides the basic scaffolding for the body. The skeletal system includes the bones, cartilage, ligaments, and…
The Cell: The Common Physiological Denominator
2The Cell: The Common Physiological Denominator Cells: A Common Denominator All physiological systems, for example, digestive, respiratory, or cardiovascular, depend on the actions and activities of cells. Groups of cells…
Muscular Tissue
7Muscular Tissue Muscle Tissue Overview Introduction Muscle tissue is specialized for contraction and is responsible for body movements and changes in size and shape of internal organs. Muscle cells are…
Introduction to the Nervous System
8Introduction to the Nervous System To maintain homeostasis, the body must be in constant communication with both the internal and external environments. Responses to these internal and external signals require…
