Veterinary anatomy terminology is essential for learning the anatomical facts of any organ or structure of an animal. Here in this article, I will discuss these terms that are used to describe the direction or position of an animal’s organs or body parts with proper diagrams.
Quick answer: anterior, posterior, lateral, medial, superior, inferior, superficial, deep, proximal, distal, cranial, caudal, rostral, palmar, plantar, axial, and abaxial are the directional terms that are used in veterinary anatomy.
Veterinary anatomy terminology
There are a number of terms that are used to indicate the position and direction of the different parts of the animal’s body accurately are known as the veterinary directional terminology.
Suppose you want to express the direction of any organs or parts of the animal that are away from the middle part (median line) of the body, then you may use the term ‘lateral’ or ‘external’. Figure 1 shows the lateral or external surface of the animal’s body.
Here, the body of the animal is divided into two equal halves, which is known as the midline or longitudinal median plane. The external or lateral surface is away from the midline or longitudinal median plane of the animal body.
Veterinary anatomy terminology chart
There are different terms that are used to express the direction of the particular organs and structures of the animal’s body. Table 1 shows the chart of the terms that are used in veterinary anatomy as directional terminology –
| Directional terms | What does it mean? |
| Anterior | Front part |
| Posterior | Back part |
| Lateral | Away from the mid-line |
| Medial | Towards the midline |
| Superior | Above portion |
| Inferior | Below part |
| Superficial | Close to upper surface |
| Deep | Below or beneath superficial |
| Proximal | Upper part towards body |
| Distal | Lower part away from the body |
| Cranial | Part that faces toward head |
| Caudal | Part faces toward tail |
| Rostral | Part faces toward nose end |
| Palmar | Surface of forelimb that faces toward the ground (in standing position) |
| Plantar | Surface of hindlimb that faces toward the ground (in standing position) |
| Axial | Line / surface towards the midline of the body or any structure |
| Abxial | Line / surface away from the midline of the body or any structure |
But, before going to learn these terms in detail with accurate examples from the animal body, you might have knowledge of the different planes. Let’s know the planes of the animal body that are used to describe the directional terms.
Planes of the animal body
There are 4 main planes of the animal body –
- Longitudinal median plane (also known as the vertical plane),
- Paramedian or sagittal plane,
- Transverse plane or cross-sectional plane, and
- Frontal plane or horizontal plane
Longitudinal median plane and paramedian plane
Longitudinal median plane or vertical plane: this plane divides the animal’s body into almost equal halves. Thus, this plane indicates the midline (median line) of the animal body.
Again, we may also apply the longitudinal median plane to any other structure or part of the animal body. For example, in the case of the forelimb or hindlimb bone, this longitudinal plane divides the specific bone into almost equal halves.
Figure 2 shows both the longitudinal median or vertical plane of the animal’s body and limb bones. However, all other planes (paramedian, transverse, and frontal) of the body are also shown in the same picture.
Paramedian or sagittal plane: this plane of the animal body or any structure is parallel to the longitudinal median plane. Thus, this plane does not divide the animal body or any part of the body into equal halves (Figure 2).
Transverse plane and frontal plane
Transverse plane or cross-sectional plane: this plane divides the animal body or any other structure into two segments (cranial and caudal, or proximal and distal).
For example, when the transverse plane is applied to the animal body, it divides the body into cranial and caudal segments. However, when this transverse plane is applied to the animal’s forelimb or hindlimb bones, it divides the specific bone into proximal (dorsal) and distal (ventral) segments.
Here, Figure 3 represents the transverse plane both on the animal body and also in the limb bones.
Frontal plane or horizontal plane: this plane divides the animal body along its long axis horizontally. Thus, this plane divides the body into dorsal and ventral portions.
All planes of the animal body are important, but longitudinal and transverse planes are used more in veterinary anatomy. Now, you may know the details of the terms that are used in veterinary anatomy perfectly.
Veterinary anatomy terminology and definition
All the terminology that is used in veterinary anatomy to express the position and direction of the animal body or body part is shown in Figure 4.
Anterior and posterior
The term anterior means the front portion of the animal body or any body parts, whereas posterior means the back portion. Figure 4 shows the anterior and posterior portions, or the surface of the forelimb of the animal.
Lateral and medial
You have already got the basic idea of the longitudinal median plane of the animal body (in Figure 2). When the surface or portion is away from the longitudinal median plane (vertical) of the animal body or any other organs, then it is known as the lateral surface or portion. This surface is also known as the external surface.
The surface or portion towards the longitudinal median plane is the medial surface. This is also called the internal surface of the specific structure of the animal body.
Here, Figure 5 shows the lateral and medial surfaces of both the animal body and limb bones.
Superior and inferior
The term superior means the above portion, whereas interior means the lower portion of any structure of an animal body. For example, the scapula of the goat’s forelimb is located superior to the humerus bone. But, these superior and inferior terms are more applicable to express the position of internal organs.
Again, the radius and ulna bones of the goat’s forelimb are located inferior to the humerus bone.
Superficial and deep
Just below the skin, you will find the loose connective tissue (white) when you dissect an animal’s body. Again, you will find a dense connective tissue layer (white) just above and around the muscle layers.
These all (white fibrous connective tissue) are fascia, and which one located just below the skin is termed superficial fascia, and which part located above and around the muscle is known as deep fascia. Figure 6 shows the superficial and deep fascia of the animal muscle.
Proximal and distal
The term proximal means the part of any structure directed toward the body. However, the term distal means the part of the specific structure (such as a bone) directed away from the body.
For example, the above part of any limb bone of an animal skeleton that is directed toward the body is the proximal end. Again, the lower part (directed away from the body) is the distal end. Figure 7 shows the proximal and distal ends of the goat’s limb bones.
Cranial, caudal, and rostral
The cranial term is applied in veterinary anatomy when the surface or portion is directed towards the head end of the animal. Again, the caudal term is applied when the surface is directed towards the tail end of the body. Finally, the rostral terms are applied to any organ or structure of the animal body when it is directed towards to nose.
Figure 8 shows the examples of cranial, caudal, and rostral from the animal body.
Palmar and plantar
The palmar term is applied only in the manus segment of forelimb bones of animals. The manus segment (consisting of carpal, metacarpal, and phalanges) contacts the ground surface in the standing position. This contact surface of the animal’s forelimb is termed the palmar surface.
Again, the pes segment (which consists of tarsal, metatarsal, and phalanges) of the animal’s hindlimb contacts the ground surface in the standing position. This contact surface of the animal’s hindlimb is term as plantar surface.
Figure 9 shows the palmar and plantar surfaces of the dog’s forelimb and hindlimb, respectively.
Axial and abaxial surface
These axial and abaxial terms are almost similar to the terms medial and lateral, respectively. Thus, the axial terms mean the surface towards the central or midline of the body or any parts of the body. Again, the abaxial terms mean the surface away from the central line of the body or any parts of the body.
Axial and abaxial surfaces are shown in Figure 10 from the ox’s digit. Here, the surface towards the axial line of the digit is the axial surface, whereas the surface away from the axial line is the abaxial surface.
Conclusion
The veterinary anatomy terminology is fundamental for learning the anatomical features of any body parts of animals. Anterior, posterior, lateral, medial, cranial, caudal, proximal, distal, axial, and abaxial indicate the position and direction of the different parts of the animal body.
But, without the planes of the animal body, few terms can’t be explained properly. Thus, you might learn both the terminology and planes of the animal body for a perfect start to learn veterinary anatomy.
References
- Getty, R., : Sisson and Grossman’s The Anatomy of the Domestic Animals, 5th Edn, W.B. Saunders & Co. Philadelphia (USA)
- Dyce, K. M., W. 0. Sack and CSG Wensing : Text Book of Veterinary Anatomy, Lea & Febiger. Philadelphia
- Ghosh, R. K. : Essentials of Veterinary Histology and Embryology, 2nd Edn.Current Books International, Kolkata.
- Ghosh, R. K. : Primary veterinary anatomy, 2nd Edn.Current Books International, Kolkata.
