1.1: Defining Anatomy

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

Master this section and you'll be able to:

• Define Anatomy
• Outline the two major subtypes of anatomy
• Give a very brief overview of the history of human anatomy

Introduction to Anatomy

Anatomy is defined as the study of body structure.  It 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. 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 20^th century, such as non-invasive imaging and radiology. For a little more detail, review the bottom of this page.

Generally, medical and biology students learn about the human body from anatomical models, skeletons, textbooks, diagrams, photographs, lectures, and tutorials. Nurses, 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.

 

There are two major types of anatomy:  

1) Gross Anatomy

Gross (or macroscopic) anatomy is the study of structural features visible to the naked eye, such as internal organs and external details. Gross anatomy can be further subdivided into three different fields:

• Surface Anatomy

This is the study of the external body and anatomical features without dissection. It focusses on the external features of the body that can be seen or felt through the skin and how they relate to deeper internal structures.

A simple example of surface anatomy is finding your collarbone (clavicle) by feeling just below your neck. You can feel the hard bone that runs horizontally from your neck to your shoulder — that is your clavicle. This is surface anatomy in action: using what you can see or touch on the outside of your body to understand what is underneath.

Another example of surface anatomy is identifying the location of the heart by using external landmarks on the chest. For instance, a clinician can locate the apex of the heart by finding the space between the 5^th and 6^th ribs on the left side of the chest, just below the nipple line. This helps guide where to place a stethoscope to listen for heart sounds or where to perform CPR.

 

• Regional Anatomy

This type of anatomy focuses on specific external and internal regions of the body (such as the head or chest) and how different systems work together in that region.  

An example of regional anatomy is the study of the thoracic region of the body. In this approach, you would examine all the structures within the chest area — including the lungs, heart, ribs, thoracic vertebrae, esophagus, blood vessels, nerves, and muscles — as a single unit, rather than studying each system (like the respiratory or circulatory system) separately.

Regional anatomy is widely used in medical schools because it is easier to apply to a clinical setting than systemic anatomy. It is especially useful in medical fields like surgery or radiology, where professionals need to understand how different structures in a particular area relate to one another in real-life situations. The major anatomy textbook, Gray’s Anatomy, for example, has recently been reorganized from a systems format to a regional format to reflect this preference. 

 

• Systemic Anatomy

Systemic anatomy, finally, focuses on the anatomy of different organ systems, such as the respiratory or nervous system. 

In this course we will use the systemic approach to study anatomy. This type of studying anatomy is widely used in introductory general anatomy courses because it breaks down the complexity of the human body into manageable, logical parts. It also studying anatomy by organ systems, makes it easier for beginners to learn and understand how each system works as a whole. For example, studying the digestive system all at once — from the mouth to the intestines — helps you see how the structures are connected and how they function together.  

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2) Microscopic Anatomy

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

• Cytology

Cytology is the study of cells. It focuses on how individual cells operate, divide, and interact with their environment. 
For example, in a Pap smear, cytology is used to examine cells from the cervix to check for abnormalities that might indicate cancer or infection.

• Histology

Histology is the study of tissues. Tissues are groups of cells that work together to perform specific functions. Histology looks at how cells are organized within tissues and how those tissues form organs.
For example, examining a biopsy of skin tissue under a microscope to check for signs of disease (like cancer or inflammation) is an application of histology.

 

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A Very Brief (and Fun) History of Anatomy & Physiology

🦴 Ancient Times – People in Egypt and Mesopotamia started learning about the body, mostly through trial, error, and guesswork. The Ebers Papyrus (c. 1550 BCE) gave early medical advice, providing interventions for common health issues of the time....some helpful, some not so. For example: It included willow bark as a remedy for general aches and pains. Willow bark is the progenitor of aspirin. A little less on target was the advice for birth control: A pessary was made from a paste of dates, acacia, and honey. This pessary was smeared onto wool and then used intravaginally to prevent conception.
 

🧠 Classical Greece (c. 400 BCE) – Hippocrates became the "Father of Medicine," promoting the idea that diseases had natural causes (not angry gods). Anatomy was still a mystery, though—dissection was a big no-no.
 

🐒 Galen’s Era (c. 150 CE) – A Roman doctor who got most of his info from animal dissection. He got a lot wrong but dominated medical thinking for over 1,000 years. 
One major example of what Galen got wrong was his belief that blood was produced in the liver and consumed by the body rather than circulated. Galen thought that blood moved through the body in a back-and-forth motion and was used up like fuel. He did not understand that the heart pumped blood in a closed circulatory system.
It was not until William Harvey's work in the 1600s that scientists realized blood circulates continuously through the body, pumped by the heart.
 

📚 The Renaissance (1500s) – Human dissection became more accepted. Andreas Vesalius published beautifully detailed anatomy books based on actual cadavers—finally correcting Galen's mistakes. Go team science!
 

🔬 1600s–1800s – Microscopes were invented, opening up a whole new microscopic world. Physiology grew as scientists began to explore how organs, tissues, and cells functioned, not just how they looked.

💉 20th Century and Beyond – Technologies like X-rays, CT scans, and MRIs revolutionized how we see inside the living body. Now we can study anatomy and physiology without making a single cut!

Figure \(\PageIndex{1}\): Rembrant’s “The Anatomy Lesson of Dr. Nicolaes Tulp”. Human anatomy is the study of the structure of the human body, from the microscopic to the macroscopic.

 

Anatomy is closely related to physiology (study of function), biochemistry (chemical processes of living things), comparative anatomy (similarities and differences between species), and embryology (development of embryos).