Chapter 1: Anatomical Terminology

• Anatomy is the study of structure, while physiology is the study of function
• Topographical anatomy focuses on the anatomy of one part in relation to other parts of the body
• Gross anatomy involves the study of structures that can be dissected and observed with the unaided eye or with a hand lens
• Applied anatomy involves the practical application of anatomical knowledge in the diagnosis and treatment of pathological conditions
• Microscopic anatomy studies structures that are too small to be seen without a light microscope
• Ultrastructural anatomy allows for the examination of structure in even greater detail using an electron microscope
• Pathological anatomy studies deviations from normal structure when an animal becomes diseased or its organs function improperly
• Embryology is the study of the development of an individual from the fertilized oocyte to birth
• Developmental anatomy studies the development of an individual from the zygote to adulthood
• Teratology is the study of abnormal development
• An understanding of directional terms is necessary for dissection
• Planes:

  • Median Plane: Divides the head, body, or limb longitudinally into equal right and left halves
  • Sagittal Plane: Passes through the head, body, or limb parallel to the median plane
  • Transverse Plane: Cuts across the head, body, or limb at a right angle to its long axis or across the long axis of an organ or a part
  • Dorsal Plane: Runs at right angles to the median and transverse planes, dividing the body or head into dorsal and ventral portions
• Directional terms:

  • Dorsal: Toward or relatively near the back and corresponding surface of the head, neck, and tail
  • Ventral: Toward or relatively near the belly and the corresponding surface of the head, neck, thorax, and tail
  • Medial: Toward or relatively near the median plane
  • Lateral: Away from or relatively farther from the median plane
  • Cranial: Toward or relatively near the head
  • Rostral: Toward or relatively near the nose
  • Caudal: Toward or relatively near the tail
  • Proximal: Relatively near the main mass or origin
  • Distal: Away from the main mass or origin
• Common regional synonyms:

  • Brachium: for the arm (between shoulder and elbow)
  • Antebrachium: for the forearm (between elbow and carpus)
  • Crus: for the leg (between stifle and tarsus)
• • Radial: On the side of the forearm in which the radius is located
  • Ulnar: On the side of the forearm in which the ulna is located
  • Tibial and Fibular: On the corresponding sides of the leg, with the tibial side being medial and the fibular side being lateral
  • Palmar: The aspect of the forepaw on which the pads are located
  • Plantar: The aspect of the hindpaw on which the pads are located
• Principles of dissection:

  • The purpose of dissection is to gain a clear understanding of the normal structures of the body and their relationships
  • Radiography and imaging procedures require a clear understanding of anatomical relationships and the ability to interpret three-dimensional anatomy from two-dimensional views
• Divides the head, body, or limb longitudinally into equal right and left halves.

  Median Plane
• Passes through the head, body, or limb parallel to the median plane.

  Sagittal Plane
• Cuts across the head, body, or limb at a right angle to its long axis or across the long axis of an organ or a part.

  Transverse Plane
• Runs at right angles to the median and transverse planes and thus divides the body or head into dorsal and ventral portions.

  Dorsal Plane
• Toward or relatively near the back and corresponding surface of the head, neck, and tail; on the limbs it applies to the upper or front surface of the carpus, tarsus, metapodium, and digits (opposite to the side with the pads).

  Dorsal
• Toward or relatively near the belly and the corresponding surface of the head, neck, thorax, and tail. This term is never used for the limbs.

  Ventral
• Toward or relatively near the median plane.

  Medial
• Away from or relatively farther from the median plane.

  Lateral
• Toward or relatively near the head; on the limbs it applies proximal to the carpus and tarsus. In reference to the head, it is replaced by the term rostral.

  Cranial
• Replaced by the term rostral.

  Cranial
• Toward or relatively near the nose; applies to the head only.

  Rostral
• Toward or relatively near the tail; on the limbs it applies proximal to the carpus and tar- sus. Also used in reference to the head.

  Caudal
• Close to, or in the di- rection of, the center of an organ, body cavity, or structure.

  Internal or Inner
• Away from the center of an organ or structure.

  External or Outer
• Relatively near the surface of the body or the surface of a solid organ.

  Superficial
• Relatively near the center of the body or the center of a solid organ.

  Deep
• Relatively near the main mass or origin; in the limbs and tail, the attached end.

  Proximal
• Away from the main mass or origin; in the limbs and tail, the free end.

  Distal
• On that side of the forearm (antebra- chium) in which the radius is located.

  Radial
• On that side of the forearm in which the ulna is located.

  Ulnar
• On the corresponding sides of the leg (crus), the tibial side being medial and the fibular side being lateral.

  Tibial and Fibular
• The aspect of the forepaw on which the pads are located—the surface that contacts the ground in the standing animal—and the corresponding surface of the metacarpus and carpus.

  Palmar
• The aspect of the hindpaw on which the pads are located—the surface that contacts the ground in the standing animal—and the cor- responding surface of the metatarsus and tarsus. The opposite surface of both forepaw and hind- paw is known as the dorsal surface.

  Plantar
• The opposite surface of both forepaw and hind- paw is known as the ...

  Dorsal Surface