Download Dissection Guidelines

Dissection
Anatomical Direction
Before beginning a dissection, it is important to have an understanding of some of the basic
directional terminology associated with the dissection of specimens. Some of these terms
include proximal, which means toward the body, and distal, which means to move away from
the body. Other important anatomical directions are indicated below.
Key Anatomical Directions
Dissection Safety
Proper safety procedures when working with dissection tools and specimens is of greatest
importance. Some safety rules to engage in when dissecting specimens are as follows.
Dissection Safety Rules
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Follow all instructions given by your teacher.
Inform your teacher of any illness as a result of exposure
to chemicals used in specimen preparation.
Avoid contact with preservative chemicals. Rinse the
specimens completely before dissection.
Know where the eye-wash fountain is if needed.
Wear safety goggles to prevent the splashing of any
chemicals into the eyes.
Properly mount dissection specimens to dissecting pan.
Do not dissect a specimen while holding it.
Handle scalpel or razor blade (safety edged) with extreme
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care.
Always cut away from your body and away from others.
Never ingest specimen parts.
Never remove specimens or specimen parts from the
classroom -- until the dissection is completed all parts of
the dissection must remain within the dissecting pan.
Properly dispose of dissected materials.
Store specimens in as directed by your teacher.
Clean up the work area and return all equipment to the
proper place when the dissection is completed.
Wash hands after each dissection.
Dissection Equipment
Dissection Equipment
The pictured dissection
equipment from left to right is
(1.) a teasing or dissection
needle which used to pull apart
muscle tissue, (2) dissecting
scissors which are used to cut
through tissue, and (3) a scalpel,
which is a knife used to slice
through and cut tissue.
Plant Dissection
Many kinds of flowering plants, such as lilies, daffodils, or tulips are commonly subjects for
dissection in biology. The flower is the plant structure specialized for reproduction in
advanced plants. The processes of meiosis and fertilization occur in the flower.
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Some Key Flower structures
petals: colored parts inside the sepals which attract insects
sepals: structures which are usually green outside the petals
which help to protect the flower
stamen: forms the male reproductive organ and consists of an
anther and a filament
anther: pollen box in which pollen grains are formed containing
the genetic material which produces sperm
filament: supports the anther
pistil or carpel: female reproductive organ which consists of
three parts
stigma: found at the top of the pistil, is often sticky and hairy
adapting it to catch and hold pollen
style: tube-like connection between the stigma and the ovary
ovary: enlarged part of the pistil attached to the receptacle (stem
tip on which the flower rests) and contains the ovules
ovules: small white structures within the walls of the ovary which
produces the plant egg cells
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Animal Dissection
The dissection of animals is important for many reasons. It helps in the learning about the
internal structures of animals. It also allows students to learn how organs and tissues are
interrelated. Another purpose of dissection is to allow the comparison of organisms in terms of
their organs and relative complexities. While many good simulations of dissections may be
observed, it seldom can replace the benefits of the actual participation in an actual dissection.
A common invertebrate organism dissected is the honey bee. Usually the dissection procedure
involves cutting the organism open on its ventral side and teasing/peeling its tissues and muscles
back to observe internal organs. Different teachers may have their own preferences in terms of
their emphasis on the tissues and organs to be observed in a dissection.
Key Internal Organs of the Honey Bee
Organ
Body System
brain
nervous
heart
circulatory
stomach
digestive
stores and begins the chemical digestion of food
midgut
digestive
finishes chemical digestion and absorbs digested nutrients
into the blood
mandibular
gland
digestive
begins chemical digestion of food in the mouth
aorta
circulatory
transports blood to the thorax and head
trachea
respiratory
exchanges gases with the external environment (aided by the
skin in the frog)
malphigian
tubules
excretory
filter wastes from the blood
venom gland
Major Function
thinking and coordination of body activities
pumps blood through the body
Immune/defen
Produces poison for stinger
se
ganglia
nervous
nerve clusters controlling reflex reactions
muscle
muscular
control movement of appendages
ovaries
reproductive
makes eggs in queen bee
testes
reproductive
makes sperm in drone bee
Honey Bee Internal Anatomy
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