Several scientific terms are used to indicate precisely the position and direction of different parts of the body of a horse’s anatomy. These are the horse directional terms which are used to describe where structures lie in relation to one another.
Many terms of direction differ significantly between human and domestic animal anatomy because of the orientation of the bipedal versus quadrupedal stance. Although the use of human anatomical nomenclature in quadrupeds usually leads to confusion.
The terms anterior, posterior, superior, and inferior are frequently used to describe the eye and aspects of dental anatomy of both human beings and domestic animals.
Horse directional terms
Cranial, caudal, dorsal, and ventral
Cranial: Cranial is a directional term meaning toward the head. The shoulder is cranial to the hip; it is closer to the head than is the hip.
Caudal: Caudal means toward the tail. The rump is caudal to the loin.
Rostral and caudal: Rostral and caudal are directional terms used in reference to features of the head to mean toward the nose (rostral) or toward the tail (caudal).
Dorsal: Dorsal means toward or beyond the backbone or vertebral column. The kidneys are dorsal to the intestines; they are closer to the vertebral column. Dorsum is the noun referring to the dorsal portion or back. A saddle is placed on the dorsum of a horse.
Ventral: Ventral means away from the vertebral column or toward the midabdominal wall. The udder is the most ventral part of the body of a cow, the part of the body farthest from the vertebral column.
Deep and superficial
Deep and internal: Deep and internal indicate proximity to the center of an anatomical structure. The humerus (arm bone) is deep in relation to all other structures in the arm.
Superficial and external: Superficial and external refer to proximity to the surface of the body. Hair is superficial to all other structures of the body.
Proximal and distal terminology for the horse
Proximal: Proximal means relatively close to a given part, usually the vertebral column, body, or center of gravity. It is generally used in reference to an extremity or limb. The carpus or knee is proximal to the foot.
Distal: Distal means farther from the vertebral column, and like proximal, it is generally used in reference to portions of an extremity. The hoof is distal to the carpus or knee.
The suffix -ad is used to form an adverb from any of the above-named directional terms, indicating movement in the direction of or toward, as in dorsad, ventrad, caudad, and craniad, that is, respectively, toward the dorsum, toward the belly, toward the tail, and toward the head.
For example, the superficial digital flexor tendon inserts on the distal limb (the adjective distal describes the noun limb), but it passes distally as it runs along the palmar aspect of the manus (the adverb distally describes the verb passes).
In describing the thoracic limb (forelimb) distal to (below) the carpus, palmar refers to the flexor or caudal surface. Dorsal is used in this region to refer to the opposite (cranial) side.
In describing the pelvic limb (hindlimb) distal to the hock, plantar refers to the caudal surface, and dorsal here, too, refers to the side directly opposite (the cranial side).
Prone, pronation, supine, and supination terms in horses
Prone: Prone refers to a position in which the dorsal aspect of the body or any extremity is uppermost.
Pronation: Pronation refers to the act of turning toward a prone position.
Supine: Spine refers to the position in which the ventral aspect of the body or palmar or plantar aspect of an extremity is uppermost.
Supination: Supination refers to the act of turning toward a supine position.
Horse planes anatomy
The horse’s anatomy is –
- Median plane,
- Sagittal plane,
- Transverse plane, and
- Horizontal plane,
Median plane in the horse
The median plane is an imaginary plane passing through the body so as to divide the body into equal right and left halves. A beef carcass is split into two halves on the median plane.
Sagittal plane in a horse
A sagittal plane (Sg) is any plane parallel to the median plane. The median plane is sometimes called the midsagittal plane.
Transverse plane in a horse
A transverse plane is at right angles to the median plane and divides the body into cranial and caudal segments. A cross-section of the body would be made on a transverse plane. The cinch of a saddle defines a transverse plane through the thorax of a horse.
Horizontal plane in a horse
A horizontal plane is at right angles to both the median plane and transverse planes. The horizontal plane divides the body into dorsal (upper) and ventral (lower) segments. If a cow walks into a lake until the water comes above the chest, the surface of the water is in a horizontal plane in relation to the cow.
All this terminology and these plans are also similarly applicable to other domestic and wild animals.
Medial and lateral terminology
In addition to the planes of reference, other descriptive terms are valuable in defining an area we wish to discuss.
Medial: Medial is an adjective meaning close to or toward the median plane. The heart is medial to the lungs; it is closer to the median plane than are the lungs. The chestnut is on the medial aspect (inside) of a horse’s limb; it is on the side closest to the median plane.
Lateral: Lateral is the antonym of medial; it means away from the median plane. The ribs are lateral to the lungs, that is, farther from the median plane.
Median term in animal
The term median is often confused with medial. Both words are used as adjectives when describing a horse’s or an animal’s anatomical structures.
Median means on the midline of the animal/horse, as in the median plane, or the median artery. Medial is subtly different, as it means toward the midline of the horse/animal’s and is a term of relativity (as it implies that there is a lateral).
Summary table for horse directional terms
| Terms/ aspect | Meaning/ areas |
| Median plane | This plane divides the body into almost two halves |
| Superficial | Close to the surface |
| Deep | Beneath the superficial |
| Cranial/anterior | toward the head |
| Caudal/posterior | toward the tail |
| Medial | inside of an area; toward the inside |
| Lateral | side of the body; toward the outside |
| Dorsal | toward the back area |
| Ventral | toward the abdomen or belly area |
| Rostral | toward the nose |
| Proximal | closer to the center of the body |
| Distal | away from the center of the body |
| Palmar | the bottom of the front feet |
| Plantar | the bottom of the rear feet |
Conclusion
So, the horse directional terms relate to the body position and are useful in recording locations relating to the body. They are also useful in surgical or radiographic positioning.
These terms relate to a specific area of the horse’s body and allow for better communication when referring to the horse’s anatomy.
References
- Beth Vanhorn and Robert W. Clark, Veterinary Assisting: Fundamentals & Applications, ISBN-13: 978-1-4354-5387-6, Maxwell Drive, Clifton Park, NY 12065-2919 USA.
- Anna Dee Fails and Christianne Magee, Anatomy and physiology of the Farm Animals, 111 River Street, Hoboken, NJ 07030, USA.
- Hilary M. Clayton, Peter F. Flood, Diana S. Rosenstein, and David Mandeville, Clinical Anatomy of the Horse, First edition 2005, ISBN 07234 3302 X.
- Pasquini and Spurgeon, Anatomy of domestic animals, systemic and regional approaches.
- Victoria Aspinall B, and Melanie Cappello, Introduction to Veterinary Anatomy and Physiology Textbook, ISBN 978-0-7020-5735-9, Elsevier.
