Longitudinal vs Transverse Section
When the anatomical structures of
animals and plants are studied, the longitudinal and transverse sections
become extremely important. This importance is mainly due to the
unveiling of the hidden tissues and organs through a longitudinal or
transverse section. Usually, a live animal cannot be dissected
longitudinally or transversely, yet the dead bodies could be studied
with these kinds of sections that will be helpful to understand the
living being of the same species.
Longitudinal Section
When a vertical section is cut along the
longest axis of an animal or a plant, the longitudinal cut is made.
However, it is sometimes defined as the longest section cut in the
vertical plane of an animal or a plant. There may be more than one
longitudinal section, and the main difference between those sections
will be the distance from the lateral ends to the sectioning plane. When
the longitudinal section is made through the line of symmetry, the
resulted section is called as a sagittal section.
In anatomy, the longitudinal cut serves
in many ways to understand the structures and their functions. The
digestive and nervous systems of elongated animals (worms or snakes) can
be easily understood only through a longitudinal section. The revealing
of internal anatomical structures through longitudinal sections enables
to make strong suggestions about the evolutionary history of modern
species when those are compared with the fossil evidences. The
longitudinal section is not limited to the entire body, but it could be
used to refer the same dissection as described above for an organ, as
well. However, such section of an organ would reveal the cellular and/or
tissue level organization. The longitudinal section of a skeletal
muscle will show the muscle fibres with their important regions, which
makes it very easy to understand the mechanism of muscle contraction and
relaxation.
Transverse Section
Transverse section is a cut made in a
plane that is made across the body of an animal, a plant, an organ, or a
tissue. It is usually referred as the cut made between left and right.
The transverse section usually runs between the lateral ends of an
organism, from left to right or the other way around. A transverse
section is right-angled with the longitudinal section. This section can
be made through different levels or heights of an organ or a structure.
Therefore, many transverse sections can be made to observe the anatomy
of an organ. As an example, the scan results of a brain show the
anatomical structure in different transverse sections, which is useful
in locating any problem in the brain. When ultrasound wave scans are
performed, the anatomical organization is studied at different levels,
which means the anatomy of the scanned organ(s) could be studied through
different transverse sections.
Usually, a transverse section would not
reveal all the structures in an animal or a plant since organs are
different tissues formed at different levels inside the organism.
Therefore, few sections have to be made to understand the entire anatomy
of an organism. The alimentary track of the animals is usually long in
all the animals, and transverse sections at different levels of the
track will reveal the anatomy and functions such as toothed mouths,
oesophagus with mucus layers, secretory stomach, absorbing guts, etc.
What is the difference between Longitudinal and Transverse Section?
• Longitudinal section runs through the anterior posterior axis, whereas the transverse section goes between lateral ends.• Longitudinal sections are usually longer than transverse sections.
• Usually, the number of possible transverse sections is higher than the number of possible longitudinal sections to be made through an organ or organism.
• Longitudinal section is right-angled to the transverse section
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