Download frog dissection

FROG DISSECTION
The frog’s digestive system is very similar to ours so we can
get an idea of what our digestive organs look like by dissecting
a frog!
PROCEDURE:
 PLACE the frog in the dissecting pan belly side up.
 FOLLOW along with your teacher on the LCD to start your
dissection.
 USE tweezers to lift the THIN skin away from the body cavity.
 CUT the same way to remove the THIN layer of muscles so that
you can see the organs.
 If there are fatty bodies (bright orange, yellow greasy noodles), use
your scissors to CUT them away. Be careful that you cut out the
fatty bodies and NOT the intestines!
 If you have a female frog you may see hundreds of eggs which
look like black dots. REMOVE these eggs.
 IDENTIFY each of the structures in the table below and check the box to show you’ve found
them.
o ASK for help from your teacher if you cannot identify a structure.

FOLLOW the guidelines below to begin your dissection.
 LAY OUT the structures on a towel on the bench to show your teacher as you cut them away
STRUCTURE /
ORGAN
GALL
BLADDER
LIVER
HEART and
LUNGS
I HAVE
FOUND IT
WHAT DOES IT LOOK LIKE AND
WHERE IS IT?
HOW DO I REMOVE IT?
Under the liver there will be a
Use scissors to carefully
dark green small “grape” which
cut it out
stores the liquid bile
Brown colored large structure
with three lobes (parts)
Use scissors to carefully
cut it out. Do not damage
the organs underneath!
At the top of the liver there is a
small triangular structure which Use scissors to cut both
is the heart. Next to it are two the heart and lungs out.
little bags which are the lungs
I HAVE
REMOVED IT
FROG DISSECTION (continued)
STRUCTURE /
ORGAN
I HAVE
WHAT DOES IT LOOK
FOUND IT LIKE AND WHERE IS IT?
HOW DO I REMOVE IT?
I HAVE
REMOVED IT
Remove the “food tube” from the
frog by cutting at the top and
bottom of it. You may also need
to cut connective tissue.
Stretch the tube out and
MEASURE the following
lengths:
DIGESTIVE
SYSTEM
Under the liver you
should now see the entire Length of frog = ______cm
digestive tube.
Length of tube =_____cm
Length of small intestines
=______cm
IDENTIFY the stomach, small
intestine, and large intestine
STOMACH
Cut lengthwise along the stomach
This leads into the small to see if there is any food inside
intestines.
the stomach! Notice the stomach
muscles-they looked ribbed.
Notice the very small blood
vessels that are around the small
intestine.
This is where take the digested
food is taken into the blood
stream.
SMALL
INTESTINE
The long thin tube that
exits the stomach
LARGE
INTESTINE
Cut into the large intestine to see
The wider tube that leads
if there is any waste (poop)
from the small intestine
there!!
Remove the KIDNEYS, which are two red organs located against the back of the frog’s abdomen.
- These can be removed by gently lifting them and cutting through the membrane that’s attached to
the back.
On both sides of the spine and extending down to the legs, you will find NERVE BUNDLES that
look like little white threads.
- If you follow up the spine and look at the back on both sides of it, you will find more small
bundles of nerves branching out on both sides.
FROG DISSECTION GUIDE