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Monday, February 11, 2013
Monday, February 11, 2013 - 1 Comment
For the identification of specific areas, the body can be divided by imaginary flat surfaces or planes.
The midsagittal plane divides the left and right sides of the body lengthwise along the midline into externally symmetrical sections. If a longitudinal plane is placed off-centre and separates the body into asymmetrical left and right sections, it is called a sagittal plane. A frontal plane divides the body into asymmetrical anterior and posterior sections.
A transverse plane divides the body horizontally into upper (superior) and lower (inferior) sections. A transverse (or horizontal) plane is at right angles to the midsagittal, sagittal, and frontal planes. Transverse planes do not produce material halves.
The system of planes is also used with parts of body, including internal parts. If your laboratory manual or any other refers a book for drawing of a sagittal section, frontal section, or a transverse section, you should be aware of what is actually being shown and how it relates to corresponding plane. A cut which produces exposed surface of the head is called a midsagittal section. A cut along a frontal plane produces a frontal section.
Some of the directional terms of the body are defined as follows:
Definition and Example
Toward the head.
e.g.: The leg is superior to the foot.
Toward the feet or tail region.
e.g.: The foot is inferior to the leg.
Toward the front of the body.
e.g.: The nose is anterior to the ears.
Toward the back of the body.
e.g.: The ears are posterior to the nose.
Toward the midline of the body.
e.g.: The nose is medial to the eyes.
Away from the midline of the body.
e.g.: The eyes are lateral to the nose.
Toward (nearer) the trunk of the body or the attached end of a limb.
e.g.: The shoulder is proximal to the wrist.
Away (farther) from the trunk of the body or the attached end of a limb.
e.g.: The wrist is distal to the forearm.
Nearer the surface of the body.
e.g.: The ribs are more superficial than the heart.
Farther from the surface of the body.
e.g.: The heart is deeper than the ribs.
Away from the central axis of the body.
e.g.: Peripheral nerves radiate away from the brain and spinal cord.