Defining Anatomy

Human anatomy is the study of the structure of the human body.

Defining Anatomy

Anatomy describes the structure and location of the different components of an organism to provide a framework for understanding. Human anatomy studies the way that every part of a human, from molecules to bones, interacts to form a functional whole.

There are two major types of anatomy. Gross (macroscopic) anatomy is the study of anatomical structures that can be seen by the naked eye, such as the external and internal bodily organs. Microscopic anatomy is the study of tiny anatomical structures such as tissues and cells.

Gross Anatomy

Gross anatomy can be further subdivided into three different fields:

Regional anatomy is widely used in modern teaching because it is easier to apply to a clinical setting than systemic anatomy. The major anatomy textbook, Gray’s Anatomy, has recently been reorganized from a systems format to a regional format to reflect this preference. Surface anatomy is also widely used to gauge the position and structure of deeper organs, tissues, and systems.

Microscopic Anatomy

Within microscopic anatomy, two topics of study are of great importance:

The human body has many layers of organization. Biological systems consist of organs that consist of tissues, and tissue in turn is made up of cells and connective tissue. Microscopic anatomy allows one to focus on these tissues and cells.

History of Anatomy

The history of anatomy has been an evolving understanding of organs and structures in the body. Beginning in Ancient Greece and developing through the Middle Ages and the Renaissance, methods of studying anatomy have advanced dramatically. This field has moved from examination of animals and cadavers through invasive dissection to the technologically complex techniques developed in the 20th century, such as non-invasive imaging and radiology.

Generally, medical and biology students learn about the human body from anatomical models, skeletons, textbooks, diagrams, photographs, lectures, and tutorials. Medical and dental students also learn through the dissection and inspection of cadavers. A thorough working knowledge of anatomy is required for all medical professionals, especially surgeons and doctors working in diagnostic specialties such as radiology.

Anatomy and Physiology

Physiology is the study of how the components of the body function, and biochemistry is the study of the chemistry of living structures. Together with anatomy, these are the three primary disciplines within the field of human biology. Anatomy provides information about structure, location, and organization of different parts of the body that is needed to truly understand physiology. Together, anatomy and physiology explain the structure and function of the different components of the human body to describe what it is and how it works.

Defining Physiology

Human physiology is the study of the mechanical, physical, and biochemical processes that support the body’s function.

Physiology is the science of the normal function of living systems. Physiology studies the processes and mechanisms that allow an organism to survive, grow, and develop. Physiological processes are the ways in which organ systems, organs, tissues, cells, and biomolecules work together to accomplish the complex goal of sustaining life.

Physiological mechanisms are the smaller physical and chemical events that make up a larger physiological process. Human physiology studies the functions of humans, their organs and cells, and how all of these functions combine to make life, growth, and development possible.

Homeostasis

Homeostatis is the maintenance of the body’s overall inner resistance to change. This resistance stabilizes the body by regulating the internal environment, even as the external environment changes. A stable internal environment is needed for normal physiological function and survival of a living system.

Maintaining a stable internal environment requires constant monitoring, mostly by the brain and nervous system. The brain, more specifically the hypothalamus, receives information from the body and responds appropriately through the release of chemical messengers such as neurotransmitters, catecholamines, and hormones. These chemical messengers signal individual organs to change their functions in order to maintain homeostasis for the whole body.

For instance, if blood oxygen levels are too low, the brain signals the muscles controlling the lungs to breathe faster to increase oxygen intake. The brain also signals the heart to beat faster so other organs and tissues receive the oxygen they need. When oxygen levels return to normal, the brain signals the lungs and heart to return to their normal rates of function, a process called feedback.

Body Systems

Traditionally, the academic discipline of physiology views the body as a collection of interacting systems, each with its own combination of functions and purposes. Each system contributes to the homeostasis of other systems and of the entire organism. No system works in isolation, and the well-being of the person depends upon the well-being of the interactions between body systems. The traditional divisions by system are somewhat arbitrary. Many organs participate in more than one system (such as the heart and kidney), and systems might be organized by function, by embryological origin, or by other categorizations.

For instance, the neuroendocrine system is the complex interactions of the neurological and endocrinological systems. Together, the neuroendocrine system regulates many physiological processes, including those that maintain homeostasis. Furthermore, many aspects of physiology are not easily categorized by traditional definitions of organ systems because they are composed of interactions between organs in multiple organ systems.

The study of how physiology is altered in disease is pathophysiology. Pathophysiology focuses on how physiological processes fail to maintain normal function, resulting in the manifestation of disease symptoms.

Anatomy and Physiology

Human anatomy deals with how all parts of the human body interact to form a functional whole. The study of anatomy is separate from the study of physiology, although the two are often taught together. While anatomy studies the structure of the parts of an organism, physiology is concerned with the way those parts function together. For example, an anatomist may study the types of tissues found in different parts of the heart, while a physiologist may study how the heart regulates blood flow to supply oxygen to other organs in the body. While anatomy and physiology study different aspects of human biology, together they provide a more complete picture of what the human body is and how it works.