Directional Terms

Question 1

median plane

Answer 1

divides the head, body, or limb longitudinally into equal right and left halves

Question 2

sagittal plane

Answer 2

passes through the head, body, or limb parallel to the median plane

Question 3

transverse plane

Answer 3

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

Question 4

dorsal plane

Answer 4

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

Question 5

dorsal

Answer 5

Toward or relatively near the upper surface (as opposed to the supporting surface) of the head, body, 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).

Question 6

ventral

Answer 6

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

Question 7

medial

Answer 7

Toward or relatively near the median plane.

Question 8

lateral

Answer 8

Away from or relatively farther from the median plane.

Question 9

cranial

Answer 9

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.

Question 10

rostral

Answer 10

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

Question 11

caudal

Answer 11

Toward or relatively near the tail; on the limbs it applies proximal to the carpus and tarsus. Also used in reference to the head.

Question 12

internal or inner

Answer 12

Close to, or in the direction of, the center of an organ, body cavity, or structure.

Question 13

external or outer

Answer 13

Away from the center of an organ or structure.

Question 14

superficial

Answer 14

Relatively near the surface of the body or the surface of a solid organ.

Question 15

deep

Answer 15

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

Question 16

proximal

Answer 16

Relatively near the main mass or origin; in the limbs and tail, the attached end of that structure.

Question 17

distal

Answer 17

Away from the main mass or origin; in the limbs and tail, the free end of that structure.

Question 18

ulnar

Answer 18

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

Question 19

tibial and fibular

Answer 19

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

Question 20

palmar

Answer 20

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.

Question 21

plantar

Answer 21

the aspect of the hindpaw on which the pads are located—the surface that contacts the ground in the standing animal—and the corresponding surface of the metatarsus and tarsus.

Question 22

dorsal surface

Answer 22

The opposite surface of both forepaw and hindpaw

Question 23

axis

Answer 23

The central line of the body or any of its parts.

Question 24

axial, abaxial

Answer 24

Of, pertaining to, or relative to the axis. In reference to the digits, the functional axis of the limb passes between the third and fourth digits. The axial surface of the digit faces the axis, and the abaxial surface faces away from the axis.

Question 25

flexion

Answer 25

The movement of one bone in relation to another in such a manner that the angle formed at their joint is reduced. The limb is retracted or folded; the digit is bent; the back is arched dorsally.

Question 26

extension

Answer 26

The movement of one bone upon another such that the angle formed at their joint increases. The limb reaches out or is extended; the digit is straightened; the back is straightened. Extension beyond 180 degrees is overextension.

Question 27

abduction

Answer 27

The movement of a part away from the median plane.

Question 28

adduction

Answer 28

The movement of a part toward the median plane.

Question 29

circumduction

Answer 29

The movement of a part when outlining the surface of a cone (e.g., the thoracic limb extended drawing a circle).

Question 30

rotation

Answer 30

The movement of a part around its long axis (e.g., the action of the radius when using a screwdriver). The direction of rotation of a limb or segment of a limb on its long axis is designated by the direction of movement of its cranial or dorsal surface (e.g., in medial rotation of the arm, the crest of the greater tubercle is turned medially).

Question 31

supination

Answer 31

Lateral rotation of the appendage so that the palmar or plantar surface of the paw faces medially.

Question 32

pronation

Answer 32

Medial rotation of the appendage from the supine position so that the palmar or plantar surface will face the substrate.