Educational resource developed at the Veterinary Anatomy Section, ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Bareilly.
📝 STANDARD DESCRIPTION:
Three Standard Planes through the standing animal:
• Median (Sagittal) Plane — vertical, splits body into RIGHT and LEFT halves of equal size.
• Sagittal Plane — any vertical plane parallel to the median plane (off-centre).
• Transverse (Cross-sectional) Plane — perpendicular to the long axis; splits body into CRANIAL and CAUDAL parts.
• Dorsal (Frontal/Horizontal) Plane — perpendicular to the median plane and to the transverse plane; splits body into DORSAL and VENTRAL parts.
Used in: imaging (CT/MRI/USG), serial dissection, anatomical descriptions.
📚 DETAILED DESCRIPTION:
ANATOMICAL PLANES
Imagine three flat sheets of glass cutting through the standing animal — these are the reference planes used in anatomy and modern imaging.
1. MEDIAN (or Mid-sagittal) Plane:
• A single vertical plane that runs along the length of the body and divides it into two equal halves — right half and left half.
• Anything 'in the median plane' (e.g., the spinal cord, linea alba) is on the midline.
2. Sagittal Planes:
• Any vertical plane parallel to the median plane.
• These produce unequal right & left portions.
3. Transverse (Cross-sectional) Plane:
• Perpendicular to the long axis of the body or limb.
• Splits body into a cranial part and a caudal part.
• On the limbs, a transverse plane is at right angles to the long bone (used to take 'serial sections' of a forelimb at carpus, mid-radius, etc.).
4. Dorsal (also called Frontal or Horizontal) Plane:
• Perpendicular to BOTH the median plane and the transverse plane.
• Splits body into a dorsal part (back/top) and a ventral part (belly/floor).
• In humans this plane is called 'coronal'.
IMAGING APPLICATION:
• Lateral radiograph = X-ray beam crosses a sagittal plane.
• VD (ventro-dorsal) or DV (dorso-ventral) radiograph = beam crosses a dorsal plane.
• CT/MRI cross-sections = transverse slices, viewed cranial-side toward observer (so animal's right is on observer's left — opposite of human medicine convention!).
// COMPARATIVE ANALYSIS
| ALL |
Veterinary CT/MRI convention: 'animal's right' is on the observer's LEFT side of the image (DICOM standard for animals). |
CLINICAL RELEVANCE
Three-view radiography: Standard for fracture diagnosis = lateral (sagittal beam) + dorsoventral (dorsal beam) + sometimes oblique. Cross-sectional CT slices are always transverse.
