By the end of this section, you will be able to:
- Apply correct anatomical terminology to identify major body structures, regions, and directional relationships
- Demonstrate and describe the standard anatomical position
- Use directional and regional terms to accurately describe the human body
- Identify and describe the three primary anatomical planes used in anatomical studies
- Differentiate between the major body cavities
1. Body Mapping and Terminology
Anatomy comes from Greek and means “cutting open”: ἀνά (ana), meaning “up,” and τέμνω (temnō), meaning “to cut”.
Physiology originates from Ancient Greek and refers to the “study of natural processes”: derived from φύσις (physis), meaning “nature” or “origin,” and -λογία (-logia), meaning “study of”.
We we train in anatomy by dissecting a cadaver (“cadere” in Latin means “to fall” or “die”).
Types of Anatomy
The levels of human body consist of the chemical level (atoms, molecules), cellular level (made of molecules), tissue (aggregation of similar cells with a specific function ), organ (aggregation of two or more different tissues integrated to perform a specific function ), organ system (consists of various organs that have similar or related functions) and organism (group of organ systems working together ).
Gross (Macroscopic) Anatomy: Focuses on body structures that can be seen without a microscope.
Microscopic Anatomy (Histology): Deals with structures at the tissue level, requiring magnification to observe.
Anatomical Position
To properly describe locations on the body, a standard frame of reference is required. This is called the anatomical position, where a person stands upright, arms at their sides, and palms facing forward with thumbs pointing outward.
Using Directional Terms
Directional terms describe where one body part is located in relation to another. For example, rather than saying “the ears are on the left or right,” we say, “the ears are lateral to the nose.”
Note: All directional terms are from the viewpoint of the individual, not the person observing.
Why Is This Important?
Imagine someone says, “My stomach hurts.” That doesn’t offer much detail.
Precise location helps in diagnosis. Details about pain location, intensity, and type can assist in identifying the root cause (Colbert et al., 2017).
Directional Language in Body Mapping
Just like a map uses terms like north, south, east, and west, we use consistent anatomical directions to prevent confusion and improve communication.
1.1. Planes of the Body
Planes and axes of movement
Directional Terms
Directional terms describe the positions of structures relative to other structures or locations in the body.
| Directional Term | Meaning |
|---|---|
| superior or cranial | above (or toward the head) toward the head end of the body; upper (example, the hand is part of the superior extremity) |
| inferior or caudal | below (or toward the feet)away from the head; lower (example, the foot is part of the inferior extremity) |
| distal | farther from the trunk or originaway from or farthest from the trunk or the point or origin of a part (example, the hand is located at the distal end of the forearm) |
| proximal | closer to the trunk or origintoward or nearest the trunk or the point of origin of a part (example, the proximal end of the femur joins with the pelvic bone) |
| superficial | toward or on the surface |
| deep (internal) | away from the surface |
| anterior (ventral) | toward the front (or toward the belly)front (example, the kneecap is located on the anterior side of the leg) |
| posterior (dorsal) | toward the rear (or toward the back)back (example, the shoulder blades are located on the posterior side of the body) |
| medial | toward the midline toward the midline of the body (example, the middle toe is located at the medial side of the foot) |
| lateral | toward the side away from the midline of the body (example, the little toe is located at the lateral side of the foot) |
Table 2.1.1 Directional Terms and Meanings (Biga et al., 2019)
Planes of the Body
There are many imaginary flat surfaces passing through the body.
The three (3) major planes are: Sagittal, Frontal (coronal), Transverse.
Figure 1.1 Planes of the Body (Biga et al., 2019)
Coronal Plane (Frontal Plane) – A vertical plane running from side to side; divides the body or any of its parts into anterior and posterior portions.
Sagittal Plane (Lateral Plane) – A vertical plane running from front to back; divides the body or any of its parts into right and left sides.
Axial Plane (Transverse Plane) – A horizontal plane; divides the body or any of its parts into upper and lower parts.
Median plane – Sagittal plane through the midline of the body; divides the body or any of its parts into right and left halves.
1.2. Major Organs in the Four Quadrants
Figure 1.2 Four Quadrant of the Stomach
The navel (belly button) serves as the reference point for visualizing the quadrants during assessments. It marks the intersection of the two planes. The terms “left/right” and “upper/lower” refer to the anatomical position, not your personal perspective. Be cautious not to confuse the right and left sides, as this is a common error among students!
Figure 1.3 Major Organs in the Four Quadrants
Right Upper Quadrant: Contains the liver, stomach, gallbladder, duodenum, right kidney, pancreas, and right adrenal gland.
Left Upper Quadrant: Includes the liver, stomach, pancreas, left kidney, spleen, and left adrenal gland.
Right Lower Quadrant: Houses the appendix, reproductive organs, and right ureter.
Left Lower Quadrant: Contains the left ureter and reproductive organs.
NOTE: Each of the four quadrants also contains portions of the small and large intestines.
Figure 2.2.3 The Nine abdominal regions
Let’s break down the right and left columns first, as they share the same names (with the left or right prefix) and are named after the bones they’re closest to. A useful tip for studying anatomy is to focus on common prefixes and suffixes—they’ll make learning easier!
Hypochondriac Regions (Left and Right):
The prefix “hypo” means below or under, and “chondriac” refers to cartilage, specifically the cartilage of the ribs. So, the hypochondriac regions are located below the ribs. You have both a right and left hypochondriac region.
Lumbar Regions (Left and Right):
The term “lumbar” refers to the lower back vertebrae, which are nearest to this region. This is how the lumbar regions got their name.
Iliac Regions (Left and Right):
The iliac crest is the top of the hip bone, and the iliac regions are located near these bones.
That covers the left and right columns. Now, let’s focus on the middle column. These regions are named based on their location relative to the stomach, rather than the bones.
Epigastric Region:
The prefix “epi” means above or over, and “gastric” refers to the stomach. So, the epigastric region is located above the stomach.
Umbilical Region:
This one is easy to remember because the umbilical region contains your navel (or umbilicus), which is the landmark where the quadrants intersect. It helps place the umbilical region in the center of the abdominal regions.
Hypogastric Region:
“Hypo” means below, and “gastric” refers to the stomach. So, the hypogastric region is located below the stomach.
To help you remember these regions, here’s a quick trick: For the left and right columns, the names go in order from top to bottom: Hypochondriac, Lumbar, and Iliac (HLI). For the middle column, the regions are Epigastric, Umbilical, and Hypogastric (EUH). Use this phrase as a memory aid: Hector Loves Isabel Every Unceasing Hour.
1.3. Body cavities
Figure 2.3.1 Body Cavities (Wakim & Grewal, 2018)
The body contains three primary cavities, each housing internal organs known as viscera.
These cavities are lined with membranes that not only cover the organs but also help anchor them in position.
Dorsal Body Cavity – this human body cavity includes the head and the posterior (back) of the trunk and holds the brain and spinal cord
is at the posterior, or back, of the body, including both the head and the back of the trunk.
The dorsal cavity is subdivided into the cranial and spinal cavities.
Cranial Cavity: Surrounded by the skull, this cavity holds the brain.
Vertebral Canal: Formed by the vertebral column, it encases the spinal cord. This canal is lined with three layers of membranes known as the meninges, which serve to protect the delicate nervous tissue from the rigid bony structure around it.
Ventral Body Cavity: is at the anterior, or front, of the trunk. Organs contained within this body cavity include the lungs, heart, stomach, intestines, and reproductive organs.
The ventral cavity allows for considerable changes in the size and shape of the organs within it as they perform their functions.
This cavity is divided into two sections by a muscular structure called the diaphragm: the thoracic cavity above and the abdominopelvic cavity below.
Thoracic Cavity: The thoracic cavity is further divided into right, left, and central areas by a structure known as the mediastinum.
The right and left sections contain the lungs, each surrounded by a double-layered membrane called the pleura.
The parietal pleura lines the inside of the rib cage.
The visceral pleura covers the surface of the lungs.
The pleural cavity is the space between these two layers.
Abdominopelvic Cavity: This cavity is divided into two parts:
The abdominal cavity, located above the pelvic brim, contains most of the digestive organs, along with the kidneys and ureters.
The pelvic cavity, found below the pelvic brim, holds the lower part of the large intestine, the urinary bladder, and the reproductive organs.
The entire abdominopelvic cavity is lined by a serous membrane called the peritoneum:
The parietal peritoneum lines the internal walls of the cavity.
The visceral peritoneum covers the external surfaces of most digestive organs.
The peritoneal cavity is the space between these layers.
The peritoneum also wraps around parts of the intestines, forming a moist membrane known as the serosa, which then continues as a transparent sheet—the mesentery—that anchors the intestines to the back (dorsal) abdominal wall. The portion that supports the large intestine is called the mesocolon.
Some organs within the abdominal cavity lie outside the peritoneum and are said to be retroperitoneal. E.g. kidneys, ureters, adrenals, aorta, vena cava.
A fatty membrane – greater omentum hangs from the inferior border of stomach and over lies the intestines.
A smaller lesser omentum extends from the superior margin of stomach to the liver.
1.4. Test yourself
1.5. I need more!
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Reference list
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Welsh Joint Education Committee (2020). Key Area 3: Movement analysis 3.3: Planes & axes of movement Knowledge Application. [online] Available at: https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_7-5/eng/el20-21_7-5_3-3.pdf.
Yousef, H., Alhajj, M. and Sharma, S. (2024). Anatomy, Skin (Integument), Epidermis. [online] PubMed. Available at: https://www.ncbi.nlm.nih.gov/books/NBK470464/.