Final answer:
The human body's structure is organized into increasingly complex levels, with cells as the basic functioning units. The central nervous system, made up of the brain and spinal cord, works with the peripheral nervous system to process and convey information. The body also consists of various interconnected organ systems that perform specific vital functions.
Step-by-step explanation:
Basic Structure and Functions of the Human Body
The human body can be understood in terms of several levels of organization, from the smallest subatomic particles to the entire biosphere. At a cellular level, the human body comprises an astounding 100 trillion cells, each of which carries out basic life processes to sustain the body. Cells are the basic units of both structure and function.
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
The CNS consists of the brain and spinal cord, with the brain being divided into three main parts: the cerebrum, cerebellum, and brainstem. Each part has distinct functions, from processing complex thoughts to regulating heart rate. The spinal cord's main function is to relay information between the brain and the body. The PNS includes all neural elements outside of the CNS, such as sensory and motor neurons, which serve as interconnected information processors crucial for all tasks of the nervous system. The structure of neurons and the functions of glial cells are essential knowledge for understanding these systems.
Levels of Body Organization and Systems
Organ systems are collections of organs that perform major functions vital to life. There are eleven organ systems, each contributing a different, but interconnected, function. For example, the circulatory system, including the heart, moves blood and nutrients throughout the body, while the digestive system, including the stomach, breaks down food into usable forms.