Meaning and Branches of Anatomy
Before you can care for a body, you need to know its map.
A patient on a ward in Enugu points to her right side, just under the ribs, and says, "It hurts here." The doctor asks the nurse to note where the pain is. One nurse writes "side of stomach". Another writes "right upper quadrant, below the costal margin". Only one of those notes will help the next person who reads the chart. This course teaches you to write the second one, and to know what lies underneath when you do.
Definition of Anatomy
The word anatomy comes from the Greek ana- (up, apart) and tomē (cutting). The earliest anatomists learned by cutting bodies open and looking, which is why dissection is still part of the subject.
Anatomy is the science that studies the structure of the body and the relationships of its parts to one another. It asks what a part is, what it looks like, where it lies and what it touches. The heart's four chambers, the 206 bones of the adult skeleton, the layers of the skin: all of that is anatomy.
| Point | Anatomy | Physiology |
|---|---|---|
| Studies | Structure (form) of the body | Function: how the parts work |
| Key question | "What is it and where is it?" | "How does it work, and why?" |
| Example: heart | Four chambers, valves, wall layers, position in the mediastinum | How the heart contracts and pumps blood, and what controls its rate |
| Example: skin | Epidermis, dermis, glands, hair follicles | Sweating to cool the body, making vitamin D |
Structure and function go together. Every structure is shaped for its job. Red blood cells are thin discs because that gives oxygen a short path in. Bones are hollow because a tube is strong yet light. Whenever you learn a structure, ask: what is this shape good for?
Branches of Anatomy
Anatomy is a big subject, so it is divided into branches according to the size of what you study and how you organise it.
| Branch | What it studies | Example |
|---|---|---|
| Gross (macroscopic) anatomy | Structures visible to the naked eye | The bones of the hand; the lobes of the liver |
| Regional anatomy | All structures in one region together | Every muscle, vessel and nerve of the forearm |
| Systemic anatomy | The body system by system | The whole skeletal system, then the muscular system |
| Surface anatomy | External features and the deeper structures they mark | Feeling the sternum to locate the heart |
| Microscopic anatomy | Structures too small to see without a microscope | Cytology (cells) and histology (tissues) |
| Developmental anatomy | Structural changes from fertilisation to old age | Embryology: development in the first eight weeks after fertilisation |
| Imaging (radiographic) anatomy | Internal structures seen by X-ray, ultrasound, CT, MRI | A chest X-ray showing the heart's outline |
| Pathological anatomy | Structural changes caused by disease | An enlarged liver in chronic heart failure |
Anatomical Terminology
Anatomy has its own language, built mostly from Latin and Greek. That sounds frightening until you realise the words are descriptive. Foramen means hole and magnum means large, so the foramen magnum is the large hole in the base of the skull where the spinal cord leaves the brain. The suffix -itis means inflammation, so appendicitis is inflammation of the appendix. Learn the word parts and hundreds of terms explain themselves.
Pause & think
Why should a nurse, and not only a surgeon, study anatomy in detail?
Spotted a mistake?