Anatomical Directions/Planes of the Body - Rat (L4) Flashcards
Study this section in conjunction with DIAGRAMS.
Cranial
“Towards the head”
Caudal
“Towards the tail”
Rostral
“Toward the nose”, used when talking about the head
Dorsal
Refers to the back of the body/where the backbone is (the upper surface in rats)
Ventral
Refers to the belly of the body (the undersurface in rats)
Anterior
“Forward”; in quadrupeds, the same direction as cranial. In bipeds, like humans, is the same direction as ventral.
Posterior
“Rearward”; in quadrupeds, the same direction as caudal. In bipeds, like humans, is the same direction as dorsal.
Distal and proximal
Describes the distance from the roots of the limbs. In a rat, the shoulder is proximal to the forelimb, and the front paw is distal to the forelimb. The distal ends of the limb are the toes. Where the limb joins the body is the proximal end.
Left and right
In anatomical directions, always pertain to the specimen’s left or right– regardless of the way the specimen is viewed by the observer.
Midline
An imaginary line that goes from the head or tail of an animal, through the center of the body.
Lateral
Refers to the side of the body (either right or left) away from the midline.
Medial
Nearer to the midline.
Longitudinal axis
Describes the direction from the caudal to cranial end of the animal.
Sagittal section/sagittal plane
A longitudinal, vertical section along the midline from the cranial to the caudal. Such a section lies in the sagittal plane. The frontal plane and the sagittal plane intersect at the midline of the animal. (Note that sections or planes parallel with– but lateral to– the sagittal plane are referred to as “parasagittal.”)
Frontal section/plane
Lies on the longitudinal axis, but horizontally, at 90 degrees from the sagittal plane. It also passes from the cranial to caudal ends, but divides dorsal from ventral.
