Overview of Anatomy and Physiology

Anatomy studies the structure and organization of body parts, while physiology examines how those parts function and the mechanisms driving those functions. Anatomy can be gross (examining large structures like the heart without a microscope) or microscopic (investigating cells and tissues using a microscope). Together, they provide a complete understanding of the human body's composition and operation.

Anatomy divides into gross anatomy, which examines large body structures like bones and organs visible without magnification, and microscopic anatomy, which investigates individual cells and tissues using a microscope. Additionally, anatomy can be studied regionally, focusing on structures within specific body regions, or systemically, examining all structures comprising a discrete body system like the muscular system.

Physiology classifies into molecular, cellular, and systemic levels based on organizational hierarchy. Systemic physiology further subdivides by organ systems, including cardiovascular physiology, which studies the heart and blood systems, and neurophysiology, which examines the nervous system. Each classification reveals how body structures function at different scales.

This principle states that human anatomical structures are designed to support their physiological functions. For example, muscles contain contractile cells that enable them to contract and move the body. Structure and function are interdependent; understanding a body part's structure helps explain how it performs its role.

Anatomy was initially studied by observing the body's exterior and injuries. Later, physicians were permitted to dissect cadavers to advance their knowledge. Dissection remains essential in medical schools and anatomy courses. Modern imaging techniques now allow clinicians to visualize internal structures in living people, such as tumors or fractures, without invasive procedures.

Homeostasis is the state of steady internal conditions maintained by living organisms. Much of physiology centers on understanding how the body maintains homeostasis through chemical and physical processes. Laboratory experiments reveal how body structures and chemical compounds work together to support life functions and preserve stable internal environments.

Anatomists use dissection to observe physical attributes and relationships between structures, along with modern imaging techniques to visualize living tissues. Physiologists employ observation with microscopes and naked eyes, manipulations, measurements, and carefully designed laboratory experiments. These methods reveal how the structural organization of the human body supports its vital functions.